Affect on Eyes, Nose, Throat:
Within a few seconds of your first puff, irritating gases (formaldehyde, ammonia, hydrogen sulfide, and others) begin to work on sensitive membranes of your eyes, nose, and throat. They make your eyes water and your nose run. They irritate your throat. If you continue smoking, these irritating gases will eventually produce a smoker’s cough. One of the reasons many smokers prefer menthol cigarettes is that menthol is an anesthetic that masks the smoker’s perception of this irritation.
Continued smoking produces abnormal thickening in the membranes lining your throat. This thickening is accompanied by cellular changes that have been linked to throat cancer.
Lungs:
From your very first puff, the smoke begins to chip away at your lung’s natural defenses. Continued exposure can completely paralyze the lungs’ natural cleansing process.
Your respiratory rate increases, forcing your lungs to work harder.
Irritating gases produce chemical injury to the tissues of your lungs and the airways leading to the lungs. This speeds up the production of mucus and leads to an increased tendency to cough up sputum.
This excess mucus serves as a breeding ground for a wide variety of bacteria and viruses. The makes you more susceptible to colds, flu, bronchitis, and other respiratory infections. And if you do come down with an infection, your body will be less able to fight it, because smoking impairs the ability of the white blood cells to resist invading organisms.
The lining of your bronchi begins to thicken, predisposing you to cancers of the bronchi. Most lung cancers arise in the bronchial lining.
Farther down, inside your lungs, the smoke weakens the free-roving scavenger cells that remove foreign particles from the air sacs of the lungs. Continued smoke exposure adversely affects elastin (the enzyme that keeps your lungs flexible), predisposing you to emphysema.
Many of the compounds you inhale are deposited as a layer of sticky tar on the lining of your throat and bronchi and in the delicate air sacs of your lungs. A pack-a-day smoker pours about eight ounces—the one full cup—of tar into his or her lungs each year. This tar is rich in cancer-producing chemicals, including radioactive poloniumm 210.
Heart:
From the moment smoke reaches your lungs, your heart is forced to work harder. Your pulse quickens, forcing your heart to beat an extra 10 to 25 times per minute, as many as 36,000 additional times per day.
Because of the irritating effect of nicotine and other components of tobacco smoke, your heartbeat is more likely to be irregular. This can contribute to cardiac arrhythmia, and many other serious coronary conditions, such as heart attack. A recent Surgeon General’s report estimated that about 170,000 heart attacks each year are caused by smoking.
Blood vessels:
Your blood pressure increases by 10 to 15 percent, putting additional stress on your heart and blood vessels, increasing your risk of heart attack and stroke.
Smoking increases your risk of vascular disease of the extremities. Severe cases may require amputation. This condition can produce pain and can increase your risk of blood clots in the lungs.
Skin:
Smoking constricts the blood vessels in your skin, decreasing the delivery of life-giving oxygen to this vital organ. As the result of this decrease in blood flow, a smoker’s skin becomes more susceptible to wrinkling. This decreased blood flow can be a special problem in people who suffer from chronically cold hands and/or feet (Raynaud’s Syndrome).
Smokers are at particularly high risk for a medical syndrome called “smoker’s face,” which is characterized by deep lines around the corners of the mouth and eyes, a gauntness of facial features, a grayish appearance of the skin, and certain abnormalities of the complexion. In one study, 46 percent of long-term smokers were found to have smoker’s face.
Blood:
Carbon monoxide—the colorless, odorless, deadly gas present in automobile exhaust—is present in cigarette smoke in more than 600 times the concentration considered safe in industrial plants. A smoker’s blood typically contains 4 to 15 times as much carbon monoxide as that of a nonsmoker. This carbon monoxide stays in the bloodstream for up to six hours after you stop smoking. A 1982 University of Pittsburgh health survey found that nearly 80 percent of cigarette smokers had potentially hazardous levels of carbon monoxide in their blood. Research suggests that these abnormally high carbon monoxide levels may play a major role in triggering heart attacks.
When you breathe in a lung-full of cigarette smoke, the carbon monoxide passes immediately into your blood, binding to the oxygen receptor sites and figuratively kicking the oxygen molecules out of your red blood cells. Hemoglobin that is bound to carbon monoxide is converted into carboxyhemoglobin, and is no longer able to transport oxygen. This means that less oxygen reaches a smoker’s brain and other vital organs. Because of this added carbon monoxide load, a smoker’s red cells are also less effective in removing carbon dioxide—a waste product—from his or her body’s cells.
If you continue to smoke for several weeks, your number of red cells begins to increase, as your body responds to chronic oxygen deprivation. This condition, characterized by an abnormally high level of red blood cells, is known as smoker’s polycythemia. In addition, smoking makes your blood clot more easily. Both of these factors may increase your risk of heart attack or stroke.
Male reproductive system:
Two recent studies by Dr. Irving Goldstein and colleagues at the New England male Reproductive Health Center, Boston University Medical School, found a possible link between smoking and erection problems. In the first study, the researchers found that among a population of 1,011 men with erection problems, 78 percent were smokers—more than twice the number of men with erection problems found in the general population. The researches concluded that decreased potency might result from the negative effects of smoking on the blood vessels leading to the male reproductive organs.
In their second study, the researchers measured the blood flow to the penis in 120 men who had come to their clinic with erection problems. They found that decrease in blood flow was proportional to the number of cigarettes smoked. Dr. Goldstein believes that smoking is the leading cause of impotence in the U.S. today.
In addition to diminishing potency, smoking adversely affects the fertility of male smokers by decreasing sperm count and sperm motility as well as altering sperm shape.
Supply of Oxygen:
Because carbon monoxide lowers your blood oxygen carrying capacity, the blood delivers less oxygen to all the organs of the body. At the cellular level, oxygen is used to supply organs with the energy they need. Less oxygen means less energy.
In addition, more than thirty cancer-causing chemicals travel via the smoker’s bloodstream to every organ of the body. The organs most sensitive to these carcinogens are the stomach, the kidneys, the bladder, and the cervix.
Cigarette smoking also weakens the immune system by depressing antibody response and depressing cell-mediated reactions to foreign invaders. As a result, smokers are more susceptible to a variety of infections. These impairments are reversible if the smoker stops smoking.
Brain
Although a smoker’s blood carries less oxygen, the nicotine in tobacco smoke increases the heart rate, requiring more oxygen. This is why smokers become short of breath more easily than nonsmokers. The high concentration of carbon monoxide also reduces the level of oxygen that is carried to the brain. This can produce lethargy, confusion, and difficulty in thinking.
Taste and Smell:
Continued smoking will also result in a loss of your senses of taste and smell. This occurs so gradually that it may go unnoticed, but the end result is the decreased sensitivity of two very important sense perceptions
Wednesday, September 15, 2010
Alcohol: Its affect of different parts of body
Before describing the affects of alcohol on the body, you should know how alcohol enters the body and what it does when it gets there. After alcohol is ingested, it reaches the stomach where about 20% of the alcohol absorbs into the blood stream, through small blood vessels. The remaining 80% of the alcohol continues to the small intestine and is absorbed there into the blood stream.
The alcohol flows through the blood stream and is metabolized by the liver, where the alcohol is broken down by enzymes. The liver can, on average, metabolize about one standard drink (i.e. one 12 ounce bottle of beer, one 4 ounce glass of wine or 1.5 ounces of 40% alcohol) in one hour. Alcohol consumed in addition to these amounts can generally not be processed by the liver. When this happens, your blood becomes saturated and the additional alcohol makes its way to your body tissues and blood stream, until your liver can process the excess alcohol.
Affect on Blood:
Extended alcohol abuse can cause blood conditions including several forms of anemia and blood clotting abnormalities. These conditions could result in susceptibility to bleeding and bruising. Prolonged alcohol use can also impair white blood cell function and thus makes the abuser more likely to become infected.
Affect on Cerebral Cortex:
The cerebral cortex processes information from your senses, processes thoughts, initiates the majority of voluntary muscle movements and has some control over lower-order brain centers. In the cerebral cortex, alcohol can:
Affect thought processes, leading to potentially poor judgement.
Depresses inhibition, leading one to become more talkative and more confident.
Blunts the senses and increases the threshold for pain.
As the BAC increases, these effects get more pronounced.
Affects on limbic system (Hippocampus)
The limbic system, which consists of the hippocampus and septal area of the brain, controls memory and emotions. The affect of alcohol on this sytem is that the person may experience some memory loss and may have exaggerated states of emotion.
Affects on Cerebellum
The cerebellum coordinates muscle movement. The cerebral cortex initiates the muscular movement by sending a signal through the medulla and spinal cord to the muscles. As the nerve signals pass through the medulla, they are influenced by nerve impulses from the cerebellum, which controls the fine movements, including those necessary for balance. When alcohol affects the cerebellum, muscle movements become uncoordinated.
Affects on Hypothalamus:
The hypothalamus controls and influences many automatic functions of the brain (through the medulla), and coordinates hormonal release (through the pituitary gland). Alcohol depresses nerve centers in the hypothalamus that control sexual arousal and performance. With increased alcohol consumption, sexual desire increases - but sexual performance declines.
Affects on Pituitary glands:
By inhibiting the pituitary secretion of anti-diuretic hormone (ADH), alcohol also affects urine excretion. ADH acts on the kidney to reabsorb water, so when it is inhibitted, ADH levels drop, the kidneys don't reabsorb as much water and the kidneys produce more urine.
Affects on Medulla:
The medulla (brain stem) influences or controls body functions that occur automatically, such as your heart rate, temperature and breathing. When alcohol affects the medulla, a person will start to feel sleepy. Increased consumption can lead to unconscious. Needless to say, alcohol's effect on the medulla can be fatal if it is excessive.
Affects on Esophagus:
Half the cancers in the esophagus, larynx and mouth are linked to alcohol. Additionally, intense vomiting from excessive drinking can tear the esophogus
Affects on Heart:
Excessive and prolonged alcohol consumption can cause contribute to conditions such as high blood pressure, heart disease and heart failure. Social drinkers who binge can get irregular heartbeats from their alcoholic habits.
Affects on Muscles:
Osteoporosis and and some forms of arthritis can be advanced by alcohol abuse. Further, alcohol can lead to muscle atrophy, which can cause sharp muscle pain and weakness.
Affects on Kidneys:
Prolonged heavy drinking can cause kidney failure. The primary functions of kidneys are to regulate the composition and volume of the fluids and electrolytes circulating through the body. The kidneys regulate water, acid/base balance, certain hormones and minerals (calcium, potassium, sodium, etc.) in the body. Alcohol can influence or compromise the balancing functions of the kidneys, and thus can cause severe consequences on kidney function and thus the body.
Affects on Liver:
Cirrhosis is a buildup of scar tissue that changes the structure of the liver and blocks blood flow. Cirrhosis can be caused by alcoholic hepatitis, which is, of course, caused by overdrinking. Cirrhosis can cause varicose veins, which can rupture and potentially triggering internal bleeding.
Affects on lungs:
Heavy drinkers are more susceptible to pneumonia and lung collapse, and also have more pulmonary infections.
Affects on Pancreas:
Alcohol can reduce the amount of digestive enzymes secreted by the pancreas, thereby inflaming and leaking digestive enzymes, which subsequently attack the pancreas itself.
Affects on Reproductive system:
Because of alcohol's affects on the brain and alcohol's effects on the kidneys, hormonal production is affected. In men, this could mean that the production of sperm and testosterone are affected, and that can lead to impotence and/or infertility. In women, estrogen metabolism in the liver can be decreased, which boost estrogen levels in the body. These changes can contribute to menstrual irregularities and potentially infertility.
Affects on Small intestine:
Alcohol can damage the cells lining the stomach and intestines, which can block the absorption and breakdown of nutrients in those organs
Affects on Stomach:
Alcohol can irritate the stomach to the point of inducing gastritis (inflammation of the stomach lining), ulcers and acid reflux. Prolonged exposure to alcohol can erode the stomach lining and cause chronic blood seepage into the stomach. If the individual is particularly unlucky, a vessel can rupture and cause major bleeding.
The alcohol flows through the blood stream and is metabolized by the liver, where the alcohol is broken down by enzymes. The liver can, on average, metabolize about one standard drink (i.e. one 12 ounce bottle of beer, one 4 ounce glass of wine or 1.5 ounces of 40% alcohol) in one hour. Alcohol consumed in addition to these amounts can generally not be processed by the liver. When this happens, your blood becomes saturated and the additional alcohol makes its way to your body tissues and blood stream, until your liver can process the excess alcohol.
Affect on Blood:
Extended alcohol abuse can cause blood conditions including several forms of anemia and blood clotting abnormalities. These conditions could result in susceptibility to bleeding and bruising. Prolonged alcohol use can also impair white blood cell function and thus makes the abuser more likely to become infected.
Affect on Cerebral Cortex:
The cerebral cortex processes information from your senses, processes thoughts, initiates the majority of voluntary muscle movements and has some control over lower-order brain centers. In the cerebral cortex, alcohol can:
Affect thought processes, leading to potentially poor judgement.
Depresses inhibition, leading one to become more talkative and more confident.
Blunts the senses and increases the threshold for pain.
As the BAC increases, these effects get more pronounced.
Affects on limbic system (Hippocampus)
The limbic system, which consists of the hippocampus and septal area of the brain, controls memory and emotions. The affect of alcohol on this sytem is that the person may experience some memory loss and may have exaggerated states of emotion.
Affects on Cerebellum
The cerebellum coordinates muscle movement. The cerebral cortex initiates the muscular movement by sending a signal through the medulla and spinal cord to the muscles. As the nerve signals pass through the medulla, they are influenced by nerve impulses from the cerebellum, which controls the fine movements, including those necessary for balance. When alcohol affects the cerebellum, muscle movements become uncoordinated.
Affects on Hypothalamus:
The hypothalamus controls and influences many automatic functions of the brain (through the medulla), and coordinates hormonal release (through the pituitary gland). Alcohol depresses nerve centers in the hypothalamus that control sexual arousal and performance. With increased alcohol consumption, sexual desire increases - but sexual performance declines.
Affects on Pituitary glands:
By inhibiting the pituitary secretion of anti-diuretic hormone (ADH), alcohol also affects urine excretion. ADH acts on the kidney to reabsorb water, so when it is inhibitted, ADH levels drop, the kidneys don't reabsorb as much water and the kidneys produce more urine.
Affects on Medulla:
The medulla (brain stem) influences or controls body functions that occur automatically, such as your heart rate, temperature and breathing. When alcohol affects the medulla, a person will start to feel sleepy. Increased consumption can lead to unconscious. Needless to say, alcohol's effect on the medulla can be fatal if it is excessive.
Affects on Esophagus:
Half the cancers in the esophagus, larynx and mouth are linked to alcohol. Additionally, intense vomiting from excessive drinking can tear the esophogus
Affects on Heart:
Excessive and prolonged alcohol consumption can cause contribute to conditions such as high blood pressure, heart disease and heart failure. Social drinkers who binge can get irregular heartbeats from their alcoholic habits.
Affects on Muscles:
Osteoporosis and and some forms of arthritis can be advanced by alcohol abuse. Further, alcohol can lead to muscle atrophy, which can cause sharp muscle pain and weakness.
Affects on Kidneys:
Prolonged heavy drinking can cause kidney failure. The primary functions of kidneys are to regulate the composition and volume of the fluids and electrolytes circulating through the body. The kidneys regulate water, acid/base balance, certain hormones and minerals (calcium, potassium, sodium, etc.) in the body. Alcohol can influence or compromise the balancing functions of the kidneys, and thus can cause severe consequences on kidney function and thus the body.
Affects on Liver:
Cirrhosis is a buildup of scar tissue that changes the structure of the liver and blocks blood flow. Cirrhosis can be caused by alcoholic hepatitis, which is, of course, caused by overdrinking. Cirrhosis can cause varicose veins, which can rupture and potentially triggering internal bleeding.
Affects on lungs:
Heavy drinkers are more susceptible to pneumonia and lung collapse, and also have more pulmonary infections.
Affects on Pancreas:
Alcohol can reduce the amount of digestive enzymes secreted by the pancreas, thereby inflaming and leaking digestive enzymes, which subsequently attack the pancreas itself.
Affects on Reproductive system:
Because of alcohol's affects on the brain and alcohol's effects on the kidneys, hormonal production is affected. In men, this could mean that the production of sperm and testosterone are affected, and that can lead to impotence and/or infertility. In women, estrogen metabolism in the liver can be decreased, which boost estrogen levels in the body. These changes can contribute to menstrual irregularities and potentially infertility.
Affects on Small intestine:
Alcohol can damage the cells lining the stomach and intestines, which can block the absorption and breakdown of nutrients in those organs
Affects on Stomach:
Alcohol can irritate the stomach to the point of inducing gastritis (inflammation of the stomach lining), ulcers and acid reflux. Prolonged exposure to alcohol can erode the stomach lining and cause chronic blood seepage into the stomach. If the individual is particularly unlucky, a vessel can rupture and cause major bleeding.
Friday, May 28, 2010
Getting to know the muscles
The Psoas major is a long fusiform muscle placed on the side of the lumbar region of the vertebral column and brim of the lesser pelvis.
the Hip flexors are a group of muscles (including the iliopsoas which passes through the pelvis) that act to flex the femur onto the lumbo-pelvic complex.
* The hip flexors include:
o Tensor fasciae latae
o Sartorius muscle
o Pectineus muscle
o Adductor longus muscle
o Adductor brevis muscle
* Part of the Quadriceps:
o Rectus femoris muscle
* Collectively known as the Iliopsoas:
o Psoas major muscle
o Psoas minor muscle
o Iliacus muscle
The muscles also contribute to flexing the lower back onto the pelvis when the pelvis is fixed, or flexing the pelvis onto the lower back when the lower back is fixed.
The Psoas minor is a long, slender muscle that is placed (when present) in front of the psoas major muscle. It is absent in 40% of individuals. It arises from the sides of the bodies of the twelfth thoracic and first lumbar vertebrae and from the intervertebral discs separating them. It ends in a long flat tendon which is inserted into the pectineal line and iliopectineal eminence, and, by its lateral border, into the iliac fascia
The Iliacus is a flat, triangular muscle, which fills the iliac fossa.
It arises from the upper two-thirds of this fossa, and from the inner lip of the iliac crest; behind, from the anterior sacroiliac and the iliolumbar ligaments, and base of the sacrum; in front, it reaches as far as the anterior superior iliac spine and anterior inferior iliac spine, and the notch between them.
The fibers converge to be inserted into the lateral side of the tendon of the Psoas major, which contributes to flexing the femur anteriorly onto the pelvis. Some of the iliacus fibers may reach the body of the femur, for about 2.5 cm. below and in front of the lesser trochanter. The Iliacus is sometimes considered a part of the Iliopsoas group of hip flexor muscles. This muscle is innervated by the anterior branches of the Femoral nerve (anterior branches of L2-3).
Getting to know the muscles
The Psoas major is a long fusiform muscle placed on the side of the lumbar region of the vertebral column and brim of the lesser pelvis.
the Hip flexors are a group of muscles (including the iliopsoas which passes through the pelvis) that act to flex the femur onto the lumbo-pelvic complex.
* The hip flexors include:
o Tensor fasciae latae
o Sartorius muscle
o Pectineus muscle
o Adductor longus muscle
o Adductor brevis muscle
* Part of the Quadriceps:
o Rectus femoris muscle
* Collectively known as the Iliopsoas:
o Psoas major muscle
o Psoas minor muscle
o Iliacus muscle
The muscles also contribute to flexing the lower back onto the pelvis when the pelvis is fixed, or flexing the pelvis onto the lower back when the lower back is fixed.
The Psoas minor is a long, slender muscle that is placed (when present) in front of the psoas major muscle. It is absent in 40% of individuals. It arises from the sides of the bodies of the twelfth thoracic and first lumbar vertebrae and from the intervertebral discs separating them. It ends in a long flat tendon which is inserted into the pectineal line and iliopectineal eminence, and, by its lateral border, into the iliac fascia
The Iliacus is a flat, triangular muscle, which fills the iliac fossa.
It arises from the upper two-thirds of this fossa, and from the inner lip of the iliac crest; behind, from the anterior sacroiliac and the iliolumbar ligaments, and base of the sacrum; in front, it reaches as far as the anterior superior iliac spine and anterior inferior iliac spine, and the notch between them.
The fibers converge to be inserted into the lateral side of the tendon of the Psoas major, which contributes to flexing the femur anteriorly onto the pelvis. Some of the iliacus fibers may reach the body of the femur, for about 2.5 cm. below and in front of the lesser trochanter. The Iliacus is sometimes considered a part of the Iliopsoas group of hip flexor muscles. This muscle is innervated by the anterior branches of the Femoral nerve (anterior branches of L2-3).
Vajrasana
Posture Like Padmasana, this is also the Asana for meditation. One can sit comfortably for a prolonged period in this Asana.
Pre position Sitting Position.
Procedure
1. Fold the left leg in the knee and place the toe on the floor.
2. Fold the right leg in the knee and place the toe on the floor and join the two toes.
3. Sit on the pit formed by the parted heels.
4. Place the palms on the knees.
Position It is important to keep the spine, the neck and the head, upright in one straight line in this Asana. Keep the sight fixed at the level of the height. Don't have any pressure on the hands. The whole weight of the body be set on the spine. Continue smooth breathing, when the final position is attained.
Releasing
1. Remove the palms from the knees and bring them to the sides.
2. Take out the left leg and straighten it.
3. Take out the right leg and straighten it.
4. Take the sitting position.
Duration After a little practice, this Asana can be maintained for a long time. In the daily routine it should be kept for five minutes to experience good results. With more practice it can be kept for three hours.
Internal Effects
Along with the body, the mind also gets stabilized in this Asana. Hence, it is preferred for meditation in this Asana. Hence, it is preferred for meditation and concentration. This Asana is alsofound to be good for Pranayama.
The special fold of the legs forms one Bandha in this Asana. Consequently the blood circulation in the waist - downward parts is controlled. For this reason this Asana is recommended after Shirshasana.
Precaution The people having stiff joints and whose movements have become difficult, should practice this Asana with a lot of care. Such persons should practice this Asana after getting the joints free and relaxed.
Pre position Sitting Position.
Procedure
1. Fold the left leg in the knee and place the toe on the floor.
2. Fold the right leg in the knee and place the toe on the floor and join the two toes.
3. Sit on the pit formed by the parted heels.
4. Place the palms on the knees.
Position It is important to keep the spine, the neck and the head, upright in one straight line in this Asana. Keep the sight fixed at the level of the height. Don't have any pressure on the hands. The whole weight of the body be set on the spine. Continue smooth breathing, when the final position is attained.
Releasing
1. Remove the palms from the knees and bring them to the sides.
2. Take out the left leg and straighten it.
3. Take out the right leg and straighten it.
4. Take the sitting position.
Duration After a little practice, this Asana can be maintained for a long time. In the daily routine it should be kept for five minutes to experience good results. With more practice it can be kept for three hours.
Internal Effects
Along with the body, the mind also gets stabilized in this Asana. Hence, it is preferred for meditation in this Asana. Hence, it is preferred for meditation and concentration. This Asana is alsofound to be good for Pranayama.
The special fold of the legs forms one Bandha in this Asana. Consequently the blood circulation in the waist - downward parts is controlled. For this reason this Asana is recommended after Shirshasana.
Precaution The people having stiff joints and whose movements have become difficult, should practice this Asana with a lot of care. Such persons should practice this Asana after getting the joints free and relaxed.
Body fat explained
What Is The Purpose Of Storing Body Fat?
Storage of fat on the body is a critical defence mechanism. Remember, the human body has not changed essentially since the Stone Age. At that time starvation and famine were ever-present dangers to survival, while over-consumption and obesity were unheard of. To enable Stone Age humans to survive periods of food scarcity, the human body was designed to store energy which could then be drawn upon in times of famine. Thus for example, people could overeat during the hunting season, or when food was plentiful, and the surplus would be stored as fat tissue (adipose tissue). And when food was short, the body would burn the deposite fat as energy. Of course Stone Age life and body chemistry was/is much more complicated than this simple explanation suggests, but it suffices to explain why we have a built-in fat storage facility.
How Are Carbs, Protein And Fat Absorbed And Stored?
The human body needs energy to power muscles and to fuel the millions of chemical and biological reactions which take place throughout our system every day. This energy comes from the food we consume in our diet. Food consists mainly of water and three types of nutrient - protein, dietary fats and carbohydrate - which are found in varying proportions in most foods. These nutrients are broken down, digested and absorbed by the body in the gastrointestinal tract, running from the mouth to the anus. Each of these macronutrients is processed and absorbed by the digestive system in different ways.
How Are Surplus Carbs Used And Stored?
Carbohydrate is the major source of energy for the body. This is because, of all nutrients, it converts most readily to glucose which is the body's preferred fuel. When we eat carbohydrate, it is converted to glucose in the digestive tract and distributed via the liver to cells throughout the body for use as energy. Once our immediate energy needs are satisfied, the remaining carb glucose is handled in one of two ways. Either it is converted to liquid glycogen (a temporary source of readily available energy) and stored in the liver or muscles. Or, it is converted into fatty acids by the liver and stored in adipose cells (fat-cells) around the body.
How Is Surplus Protein Used And Stored?
Protein is broken down into amino acids in the stomach and small intestine, then distributed via the liver to cells throughout the body for a variety of uses included cell formation and repair. Some surplus protein amino acids are kept circulating in the bloodstream, the remainder is either converted into a type of simple sugar and used as energy, or (like carbohydrate) is converted to fatty acid and stored in adipose cells.
How Is Surplus Dietary Fat Used And Stored?
Dietary fat is broken down into fatty acids and glycerol by the stomach and small intestine. It is then distributed (in the form of triglycerides) via the lymphatic system and bloodstream to the cells for a variety of specialized uses or, in the absence of sufficient carbs, for energy. However, since dietary fat cannot be converted into protein and only about 5 percent (the glycerol part) is convertible into glucose, and because dietary fat is not the body's preferred choice of fuel, a significant amount ends up being stored as body fat in the adipose tissue.
Conversion Of Body Fat To Energy
If energy is required suddenly, the body first uses up its glycogen reserves. After this, it converts the body fat in the adipose cells into energy by a catabolic process called lipolysis. During lipolysis, triglycerides within the adipose cells are acted upon by a complex enzyme called hormone sensitive lipase (HSL). This converts the triglyceride into fatty acids and glycerol. The fatty acids are then transported via the bloodstream to tissues for use as energy, or (along with the glycerol) taken to the liver for further processing.
Adipose Tissue
Adipose cells which make up adipose tissue are specialized cells which contain and can synthesize globules of fat. This fat either comes from the dietary fat we eat or is made by the body from surplus carbohydrate or protein in our diet. Adipose tissue is mainly located just under the skin, although adipose deposits are also found between the muscles, in the abdomen, and around the heart and other organs. The location of fat deposits is largely determined by genetic inheritance. Thus it is not possible to affect where we store fat. Nor is it possible to influence from which area the body burns fat for energy purposes.
Why Do We Get Fat?
Most of us develop body fat because we eat more calories than we burn in exercise. Given a culture which emphasises "value for money food portions" and "super-sizing", along with an steady increase in serving size, an upsurge of new tasty high-calorie foods and energy drinks, such over-consumption is perhaps only to be expected. Lack of exercise is also a major contributory factor. However, overeating and lack of fitness is not the whole story.
Why Are So Many People Obese?
The prevalence and incidence of obesity (the disease of excess body fat) has risen considerably over the past 25 years, both in the developed and undeveloped world. Why is this? We don't know for sure. Despite extensive research into the causes and predictors of obesity, they remain unquantified. In other words, although we know that (eg) excessive calorie intake, lack of exercise, metabolic disorders and genetic inheritance all impact on the incidence and symptoms of obesity, experts still don't know the relative contribution of these causal factors. The only thing that most experts agree on, is that the recent upsurge in obesity cannot be attributed in any major way to the influence of genes, since genetic changes typically take millennia to appear, not two decades. Even so, the connections between type 2 diabetes, raised blood fats, obesity and insulin insensitivity - a cluster of symptoms which form the condition known as insulin resistance syndrome - is evidence of a progressive deterioration in the body's metabolic efficiency, which may be a growing underlying factor in the development of excess body fat among many people.
Storage of fat on the body is a critical defence mechanism. Remember, the human body has not changed essentially since the Stone Age. At that time starvation and famine were ever-present dangers to survival, while over-consumption and obesity were unheard of. To enable Stone Age humans to survive periods of food scarcity, the human body was designed to store energy which could then be drawn upon in times of famine. Thus for example, people could overeat during the hunting season, or when food was plentiful, and the surplus would be stored as fat tissue (adipose tissue). And when food was short, the body would burn the deposite fat as energy. Of course Stone Age life and body chemistry was/is much more complicated than this simple explanation suggests, but it suffices to explain why we have a built-in fat storage facility.
How Are Carbs, Protein And Fat Absorbed And Stored?
The human body needs energy to power muscles and to fuel the millions of chemical and biological reactions which take place throughout our system every day. This energy comes from the food we consume in our diet. Food consists mainly of water and three types of nutrient - protein, dietary fats and carbohydrate - which are found in varying proportions in most foods. These nutrients are broken down, digested and absorbed by the body in the gastrointestinal tract, running from the mouth to the anus. Each of these macronutrients is processed and absorbed by the digestive system in different ways.
How Are Surplus Carbs Used And Stored?
Carbohydrate is the major source of energy for the body. This is because, of all nutrients, it converts most readily to glucose which is the body's preferred fuel. When we eat carbohydrate, it is converted to glucose in the digestive tract and distributed via the liver to cells throughout the body for use as energy. Once our immediate energy needs are satisfied, the remaining carb glucose is handled in one of two ways. Either it is converted to liquid glycogen (a temporary source of readily available energy) and stored in the liver or muscles. Or, it is converted into fatty acids by the liver and stored in adipose cells (fat-cells) around the body.
How Is Surplus Protein Used And Stored?
Protein is broken down into amino acids in the stomach and small intestine, then distributed via the liver to cells throughout the body for a variety of uses included cell formation and repair. Some surplus protein amino acids are kept circulating in the bloodstream, the remainder is either converted into a type of simple sugar and used as energy, or (like carbohydrate) is converted to fatty acid and stored in adipose cells.
How Is Surplus Dietary Fat Used And Stored?
Dietary fat is broken down into fatty acids and glycerol by the stomach and small intestine. It is then distributed (in the form of triglycerides) via the lymphatic system and bloodstream to the cells for a variety of specialized uses or, in the absence of sufficient carbs, for energy. However, since dietary fat cannot be converted into protein and only about 5 percent (the glycerol part) is convertible into glucose, and because dietary fat is not the body's preferred choice of fuel, a significant amount ends up being stored as body fat in the adipose tissue.
Conversion Of Body Fat To Energy
If energy is required suddenly, the body first uses up its glycogen reserves. After this, it converts the body fat in the adipose cells into energy by a catabolic process called lipolysis. During lipolysis, triglycerides within the adipose cells are acted upon by a complex enzyme called hormone sensitive lipase (HSL). This converts the triglyceride into fatty acids and glycerol. The fatty acids are then transported via the bloodstream to tissues for use as energy, or (along with the glycerol) taken to the liver for further processing.
Adipose Tissue
Adipose cells which make up adipose tissue are specialized cells which contain and can synthesize globules of fat. This fat either comes from the dietary fat we eat or is made by the body from surplus carbohydrate or protein in our diet. Adipose tissue is mainly located just under the skin, although adipose deposits are also found between the muscles, in the abdomen, and around the heart and other organs. The location of fat deposits is largely determined by genetic inheritance. Thus it is not possible to affect where we store fat. Nor is it possible to influence from which area the body burns fat for energy purposes.
Why Do We Get Fat?
Most of us develop body fat because we eat more calories than we burn in exercise. Given a culture which emphasises "value for money food portions" and "super-sizing", along with an steady increase in serving size, an upsurge of new tasty high-calorie foods and energy drinks, such over-consumption is perhaps only to be expected. Lack of exercise is also a major contributory factor. However, overeating and lack of fitness is not the whole story.
Why Are So Many People Obese?
The prevalence and incidence of obesity (the disease of excess body fat) has risen considerably over the past 25 years, both in the developed and undeveloped world. Why is this? We don't know for sure. Despite extensive research into the causes and predictors of obesity, they remain unquantified. In other words, although we know that (eg) excessive calorie intake, lack of exercise, metabolic disorders and genetic inheritance all impact on the incidence and symptoms of obesity, experts still don't know the relative contribution of these causal factors. The only thing that most experts agree on, is that the recent upsurge in obesity cannot be attributed in any major way to the influence of genes, since genetic changes typically take millennia to appear, not two decades. Even so, the connections between type 2 diabetes, raised blood fats, obesity and insulin insensitivity - a cluster of symptoms which form the condition known as insulin resistance syndrome - is evidence of a progressive deterioration in the body's metabolic efficiency, which may be a growing underlying factor in the development of excess body fat among many people.
Body Fat
If you want to lose weight and maintain good health, it's beneficial to understand why body fat is an important factor for weight loss and health. See also Body Fat Calculators
Body Weight and Body Fat
Body weight may be divided into three types: bones, muscle and fat. In a healthy female of average weight, bones make up 12 percent of total body weight, muscle/lean tissue about 35 percent and body fat about 27 percent. The remaining body weight is skin, connective tissue, tendons, blood, organs and so forth.
Body Fat is Lighter Than Muscle by Volume
Fat is lighter by volume than lean body tissue. For example, a 'cup' of fat is lighter than a 'cup' of muscle. This explains why increased physical exercise (which builds muscle) may actually cause weight gain rather than weight loss - at least to begin with.
Body Fat Requires Fewer Calories Than Muscle
Fat is metabolically less active than muscle. Meaning, it needs less calories to sustain it, than muscle. This is why body fat percentage is so important for weight control. The higher your percentage of fat (and the smaller your percentage of muscle) the less calories you need to maintain your weight and therefore the easier it is to gain weight.
Body Fat Percentage
Body fat is often expressed as our "Body Fat Percentage" or "Body Fat Percent." Body fat percentage is the amount of body-fat-tissue as a percentage of total body weight. If your total body weight is 160 pounds and you have 32 pounds of fat, your body fat percentage is 20 percent.
Body Fat Calculation and Health
The higher your percentage of fat above average levels, the higher your health risk for weight-related illness, like heart disease, high blood pressure, gallstones, type 2 diabetes, osteoarthritis, and certain cancers.
Body Fat Location, Abdominal Fat and Body Fat Percentage
As we can see, the total amount of body fat we have is an important factor in weight control. But where our fat is stored is also important - especially for health. In simple terms, the more fat we have around our middle (abdominal fat, or visceral fat) the worse for our health. Excess abdominal fat has a strong link to "syndrome X," the deadly quartet of high insulin, high sugar, high cholesterol, and high blood pressure. Even in people who don't have all these problems, excess abdominal fat is associated with high levels of LDL ("bad") cholesterol and low levels of HDL ("good") cholesterol. All in all, abdominal fat is strongly linked to an increased risk of heart disease and stroke and is far more hazardous to health than lower-body fat.
Who Develops Excess Abdominal Fat?
Generally, men tend to store fat around their middle (apple body shape), while women store fat around their pelvis, thighs and butt (pear body shape). But while gender is the most powerful influence on the distribution of body fat, it's not the only factor - genes and genetics also count. A 1996 study of twins found that hereditary factors are responsible for up to 70 percent of an individual's tendency to accumulate extra weight in the midsection. Age, too, has an effect. Aging is actually responsible for the middle-age spread so common in America. But the effect of age is magnified enormously by the final factor, lack of exercise. A recent study of 427 healthy men between 17 and 90 found that in each decade of adult life, the body fat of sedentary men increased 17 percent and the waist circumference 2 percent; regular exercise, though, reduced fat accumulation to just 3 percent per decade and held the mid-body bulge to just 1 percent per decade.
For a concise explanation of how ALL surplus calories (from fats, protein AND carbs) are converted to body fat and stored as adipose tissue, see How We Gain Body Fat?
Waist Circumference - Indicator of Body Fat Location
A high waist circumference is associated with an increased risk for type 2 diabetes, dyslipidemia, hypertension, and cardiovascular disease CVD in patients with a body mass index (BMI) between 25-34.9. Furthermore, in obese patients with metabolic complications, changes in waist circumference are useful predictors of changes in CVD risk factors.
Unhealthy Waist Circumference
If you are overweight (BMI 25+), then as a very general rule, an unhealthy waist circumference is above 35 inches (women), or above 40 inches (men).
Body Weight and Body Fat
Body weight may be divided into three types: bones, muscle and fat. In a healthy female of average weight, bones make up 12 percent of total body weight, muscle/lean tissue about 35 percent and body fat about 27 percent. The remaining body weight is skin, connective tissue, tendons, blood, organs and so forth.
Body Fat is Lighter Than Muscle by Volume
Fat is lighter by volume than lean body tissue. For example, a 'cup' of fat is lighter than a 'cup' of muscle. This explains why increased physical exercise (which builds muscle) may actually cause weight gain rather than weight loss - at least to begin with.
Body Fat Requires Fewer Calories Than Muscle
Fat is metabolically less active than muscle. Meaning, it needs less calories to sustain it, than muscle. This is why body fat percentage is so important for weight control. The higher your percentage of fat (and the smaller your percentage of muscle) the less calories you need to maintain your weight and therefore the easier it is to gain weight.
Body Fat Percentage
Body fat is often expressed as our "Body Fat Percentage" or "Body Fat Percent." Body fat percentage is the amount of body-fat-tissue as a percentage of total body weight. If your total body weight is 160 pounds and you have 32 pounds of fat, your body fat percentage is 20 percent.
Body Fat Calculation and Health
The higher your percentage of fat above average levels, the higher your health risk for weight-related illness, like heart disease, high blood pressure, gallstones, type 2 diabetes, osteoarthritis, and certain cancers.
Body Fat Location, Abdominal Fat and Body Fat Percentage
As we can see, the total amount of body fat we have is an important factor in weight control. But where our fat is stored is also important - especially for health. In simple terms, the more fat we have around our middle (abdominal fat, or visceral fat) the worse for our health. Excess abdominal fat has a strong link to "syndrome X," the deadly quartet of high insulin, high sugar, high cholesterol, and high blood pressure. Even in people who don't have all these problems, excess abdominal fat is associated with high levels of LDL ("bad") cholesterol and low levels of HDL ("good") cholesterol. All in all, abdominal fat is strongly linked to an increased risk of heart disease and stroke and is far more hazardous to health than lower-body fat.
Who Develops Excess Abdominal Fat?
Generally, men tend to store fat around their middle (apple body shape), while women store fat around their pelvis, thighs and butt (pear body shape). But while gender is the most powerful influence on the distribution of body fat, it's not the only factor - genes and genetics also count. A 1996 study of twins found that hereditary factors are responsible for up to 70 percent of an individual's tendency to accumulate extra weight in the midsection. Age, too, has an effect. Aging is actually responsible for the middle-age spread so common in America. But the effect of age is magnified enormously by the final factor, lack of exercise. A recent study of 427 healthy men between 17 and 90 found that in each decade of adult life, the body fat of sedentary men increased 17 percent and the waist circumference 2 percent; regular exercise, though, reduced fat accumulation to just 3 percent per decade and held the mid-body bulge to just 1 percent per decade.
For a concise explanation of how ALL surplus calories (from fats, protein AND carbs) are converted to body fat and stored as adipose tissue, see How We Gain Body Fat?
Waist Circumference - Indicator of Body Fat Location
A high waist circumference is associated with an increased risk for type 2 diabetes, dyslipidemia, hypertension, and cardiovascular disease CVD in patients with a body mass index (BMI) between 25-34.9. Furthermore, in obese patients with metabolic complications, changes in waist circumference are useful predictors of changes in CVD risk factors.
Unhealthy Waist Circumference
If you are overweight (BMI 25+), then as a very general rule, an unhealthy waist circumference is above 35 inches (women), or above 40 inches (men).
Human digestive system
What Is Digestion?
The human body obtains the energy and nutrients it needs from food. However, our cells cannot absorb these nutritional benefits until the food has been "digested" - meaning, "processed and converted into a useable form". Thus digestion is the complex process of breaking down food molecules into energy and other useful components, which can then be absorbed into the bloodstream and distributed throughout the body to maintain good health. Food remnants which are not absorbed during the digestion process are expelled as waste in the form of feces.
Where Do We Digest Our Food?
The digestion of food in humans takes place in the gastrointestinal tract - a series of hollow organs (mouth, esophagus, stomach, large and small intestines) connected to form a long tube of about 24 feet in length which extends from the mouth to the anus. It is also referred to as the GI Tract, the alimentary canal, the digestive tract, or the gut. Above the large intestine, the digestive system is sometimes called the upper gastrointestinal tract, while everything below is the lower gastrointestinal tract. The tract has muscular walls that propel food along the tube (a process called peristalsis) breaking it down and mixing it with digestive juices for optimum absorption.
The Functions Of The Digestive Tract
The gastrointestinal tract has four main functions. It ingests the food we eat; it breaks it down into simple chemical components for energy and nutritional purposes; it extracts nutrients from it (eg. macronutrients such as carbs, fats, proteins; as well as micronutrients like vitamins and minerals); and finally it expels the remaining food waste.
Figure 1. Diagram Of Digestive System
How Food Passes Through The Digestive Tract
During eating, food passes from the mouth into the esophagus, then into the stomach from where it enters the small intestine (comprising the duodenum, jejunum and ileum). Most if not all nutrients are absorbed in the stomach and small intestine. The remaining water and waste products then pass into the large intestine (comprising the cecum, colon and rectum) from where it leaves the body via the anus. Other organs which contribute to healthy digestion include the liver, the pancreas and the gallbladder. A number of important digestive hormones and digestive enzymes help to regulate digestion, especially in the the upper gastrointestinal tract. The movement of food through the main digestive tubes (esophagus, small intestine and large intestine) is maintained by a series of muscular contractions called peristalsis. Several muscular valves control the passage of food and prevent it from moving backwards. On average, it takes about 40-45 hours for food remnants to pass through the entire digestive tract.
Step-By-Step Guide To The Digestive Process
The Mouth
Digestion starts in the mouth - the beginning of the digestive tract. Food smells cause the salivary glands in the mouth to secrete saliva ("mouth-watering"), so even before we start eating our digestive system is primed and ready for action! Saliva contains antibacterial compounds and various enzymes to aid the breakdown of food molecules. It also softens the food - enabling the tongue to mould it into a bolus or ball for swallowing. The tongue, teeth and saliva work together to start digestion and aid swallowing. Teeth chop and grind food, breaking the food down into pieces small enough to be digested and increasing the surface area over which the digestive enzymes in saliva can act. For more, see Guide To Digestion In The Mouth.
The Pharynx and Esophagus
Food is then swallowed and passes into the pharynx, or throat. When we swallow, passages to the lungs (windpipe) and the nasal cavity are automatically closed, and the food goes into the esophagus - a muscular tube extending from the pharynx to the stomach. Food is propelled through the esophagus and into the stomach by means of muscular contractions called peristalsis. At the bottom of the esophagus, just before the opening to the stomach is a ring-shaped muscle known as the lower esophageal sphincter (LES). This muscle relaxes (opens) to let food into the stomach and then tightens (closes) to prevent regurgitation. If the LES malfunctions and allows food in the stomach to re-enter the esophagus, it may cause a condition called gastroesophageal reflux disease (GERD), characterised by heartburn and regurgitation. For more, see Guide To Digestion In The Esophagus.
The Stomach
A large pouch with strong muscular walls, the stomach serves as a temporary holding station and food-processor for the chewed and swallowed food. It has the ability to expand or contract depending upon the amount of food it contains. The stomach aids digestion in two ways. Its strong muscular walls churn the food into chyme - a semi-fluid mixture resembling porridge - while glands within the walls secrete gastric juice - a blend of hydrochloric acid and various digestive enzymes - that helps to digest foods like protein, fats, a few carbohydrates and alcohol. To prevent the stomach from digesting itself(!) its walls are lined with a membrane called mucosa which secretes a protective slimy substance called mucus. Liquids pass through the stomach in a matter of minutes, while solid food can remain in the stomach for up to 5 hours. Chyme slowly exits the stomach and passes into the small intestine. For more, see Guide To Digestion In The Stomach.
The Small Intestine
Approximately 17 feet in length, the small intestine is a coiled tube made up of three sections - the duodenum, jejunum and ileum. As the semi-digested food (chyme) enters the duodenum from the stomach, the duodenal lining releases intestinal hormones that stimulate the gallbladder and pancreas to release special digestive juices (bile and pancreatic juice) which help to further break down food molecules in the chyme. It is in the small intestine that most nutrients are digested and absorbed, although different nutrients are absorbed at different speeds. Typically carbs are digested most rapidly, followed by proteins and finally fats. Micronutrients (vitamins and minerals) consist of molecules tiny enough for the body to absorb without breaking them down first, but water soluble vitamins are absorbed faster than fat soluble ones. The duodenum and jejunum is where the chyme is broken down, while the ileum is responsible for absorbing nutrients into the bloodstream. The absorbed nutrients pass through the bloodstream to the liver where they are processed and either stored or distributed to other parts of the body. After every useful, digestible ingredient other than water has been wrung out of the chyme, the remaining "waste" passes into the large intestine. For more, see Guide To Digestion In The Small Intestine.
Surplus Energy Converts To Stored Body Fat
Aside from breaking down and absorbing nutrients, the digestive system also converts food into energy to help power the muscles and fuel the millions of chemical reactions needed to sustain good health. After immediate energy requirements have been satisfied, any remaining surplus is stored as glycogen (a small reserve of liquid energy stored in the liver and muscles), or body fat. For more, see Guide To Body Fat And Adipose Tissue/Body Fat - How We Gain Fat.
The Large Intestine
Also known as the large bowel, the large intestine - consisting of 3 sections, the cecum, colon and rectum - is approximately 5 feet in length and has two main functions: to absorb all remaining water from the food waste and to compress the remaining matter into a compact bundle (feces or stool) so that defecation (excretion of waste) is easy and convenient. The cecum is a short pouch containing a valve which opens to receive chyme from the ileum. The colon absorbs water and through bacterial action reduces the bulk of fiber in the feces. The rectum is the terminal segment of the digestive tract, in which feces accumulate just prior to discharge. They are discharged through the anus which contains two important muscles - the internal sphincter and the external sphincter. The internal sphincter is always tight, except when feces enter the rectum, in order to keep us continent (eg) when we are asleep. When we get an urge to defecate, we depend upon the external sphincter to keep the stool in until we go to the toilet. In total, it takes about 36-48 hours or longer for waste matter to pass through the large intestine. As in the esophagus and the small intestine, the contents of the large intestine are pushed forward by a sequence of muscular contractions called peristalsis (a type of motility or muscular movement). Peristalsis is regulated by a large network of nerves, hormones and muscles. Malfunction of any of these components may lead to a range of intestinal problems, including indigestion and constipation. For more, see Guide To Digestion In The Large Intestine.
Indigestion And Other Digestive Disorders
Bad eating habits - like over consumption of refined carbs, or lack of dietary fiber - can cause constipation, indigestion, nonulcer dyspepsia, or can lead to certain specific digestion-related conditions such as diverticulosis and Irritable Bowel Syndrome (IBS), or nutritional deficiencies. Other digestive disorders include candida, celiac disease and lactose intolerance. Viral infections can lead to diarrhea and gastroenteritis for which specific anti-diarrhea dietary treatment may be urgently required. Lastly, ingested food toxins can cause a number of unpleasant digestive complaints or even food poisoning. For more, see Diet Advice For Digestion Problems.
The human body obtains the energy and nutrients it needs from food. However, our cells cannot absorb these nutritional benefits until the food has been "digested" - meaning, "processed and converted into a useable form". Thus digestion is the complex process of breaking down food molecules into energy and other useful components, which can then be absorbed into the bloodstream and distributed throughout the body to maintain good health. Food remnants which are not absorbed during the digestion process are expelled as waste in the form of feces.
Where Do We Digest Our Food?
The digestion of food in humans takes place in the gastrointestinal tract - a series of hollow organs (mouth, esophagus, stomach, large and small intestines) connected to form a long tube of about 24 feet in length which extends from the mouth to the anus. It is also referred to as the GI Tract, the alimentary canal, the digestive tract, or the gut. Above the large intestine, the digestive system is sometimes called the upper gastrointestinal tract, while everything below is the lower gastrointestinal tract. The tract has muscular walls that propel food along the tube (a process called peristalsis) breaking it down and mixing it with digestive juices for optimum absorption.
The Functions Of The Digestive Tract
The gastrointestinal tract has four main functions. It ingests the food we eat; it breaks it down into simple chemical components for energy and nutritional purposes; it extracts nutrients from it (eg. macronutrients such as carbs, fats, proteins; as well as micronutrients like vitamins and minerals); and finally it expels the remaining food waste.
Figure 1. Diagram Of Digestive System
How Food Passes Through The Digestive Tract
During eating, food passes from the mouth into the esophagus, then into the stomach from where it enters the small intestine (comprising the duodenum, jejunum and ileum). Most if not all nutrients are absorbed in the stomach and small intestine. The remaining water and waste products then pass into the large intestine (comprising the cecum, colon and rectum) from where it leaves the body via the anus. Other organs which contribute to healthy digestion include the liver, the pancreas and the gallbladder. A number of important digestive hormones and digestive enzymes help to regulate digestion, especially in the the upper gastrointestinal tract. The movement of food through the main digestive tubes (esophagus, small intestine and large intestine) is maintained by a series of muscular contractions called peristalsis. Several muscular valves control the passage of food and prevent it from moving backwards. On average, it takes about 40-45 hours for food remnants to pass through the entire digestive tract.
Step-By-Step Guide To The Digestive Process
The Mouth
Digestion starts in the mouth - the beginning of the digestive tract. Food smells cause the salivary glands in the mouth to secrete saliva ("mouth-watering"), so even before we start eating our digestive system is primed and ready for action! Saliva contains antibacterial compounds and various enzymes to aid the breakdown of food molecules. It also softens the food - enabling the tongue to mould it into a bolus or ball for swallowing. The tongue, teeth and saliva work together to start digestion and aid swallowing. Teeth chop and grind food, breaking the food down into pieces small enough to be digested and increasing the surface area over which the digestive enzymes in saliva can act. For more, see Guide To Digestion In The Mouth.
The Pharynx and Esophagus
Food is then swallowed and passes into the pharynx, or throat. When we swallow, passages to the lungs (windpipe) and the nasal cavity are automatically closed, and the food goes into the esophagus - a muscular tube extending from the pharynx to the stomach. Food is propelled through the esophagus and into the stomach by means of muscular contractions called peristalsis. At the bottom of the esophagus, just before the opening to the stomach is a ring-shaped muscle known as the lower esophageal sphincter (LES). This muscle relaxes (opens) to let food into the stomach and then tightens (closes) to prevent regurgitation. If the LES malfunctions and allows food in the stomach to re-enter the esophagus, it may cause a condition called gastroesophageal reflux disease (GERD), characterised by heartburn and regurgitation. For more, see Guide To Digestion In The Esophagus.
The Stomach
A large pouch with strong muscular walls, the stomach serves as a temporary holding station and food-processor for the chewed and swallowed food. It has the ability to expand or contract depending upon the amount of food it contains. The stomach aids digestion in two ways. Its strong muscular walls churn the food into chyme - a semi-fluid mixture resembling porridge - while glands within the walls secrete gastric juice - a blend of hydrochloric acid and various digestive enzymes - that helps to digest foods like protein, fats, a few carbohydrates and alcohol. To prevent the stomach from digesting itself(!) its walls are lined with a membrane called mucosa which secretes a protective slimy substance called mucus. Liquids pass through the stomach in a matter of minutes, while solid food can remain in the stomach for up to 5 hours. Chyme slowly exits the stomach and passes into the small intestine. For more, see Guide To Digestion In The Stomach.
The Small Intestine
Approximately 17 feet in length, the small intestine is a coiled tube made up of three sections - the duodenum, jejunum and ileum. As the semi-digested food (chyme) enters the duodenum from the stomach, the duodenal lining releases intestinal hormones that stimulate the gallbladder and pancreas to release special digestive juices (bile and pancreatic juice) which help to further break down food molecules in the chyme. It is in the small intestine that most nutrients are digested and absorbed, although different nutrients are absorbed at different speeds. Typically carbs are digested most rapidly, followed by proteins and finally fats. Micronutrients (vitamins and minerals) consist of molecules tiny enough for the body to absorb without breaking them down first, but water soluble vitamins are absorbed faster than fat soluble ones. The duodenum and jejunum is where the chyme is broken down, while the ileum is responsible for absorbing nutrients into the bloodstream. The absorbed nutrients pass through the bloodstream to the liver where they are processed and either stored or distributed to other parts of the body. After every useful, digestible ingredient other than water has been wrung out of the chyme, the remaining "waste" passes into the large intestine. For more, see Guide To Digestion In The Small Intestine.
Surplus Energy Converts To Stored Body Fat
Aside from breaking down and absorbing nutrients, the digestive system also converts food into energy to help power the muscles and fuel the millions of chemical reactions needed to sustain good health. After immediate energy requirements have been satisfied, any remaining surplus is stored as glycogen (a small reserve of liquid energy stored in the liver and muscles), or body fat. For more, see Guide To Body Fat And Adipose Tissue/Body Fat - How We Gain Fat.
The Large Intestine
Also known as the large bowel, the large intestine - consisting of 3 sections, the cecum, colon and rectum - is approximately 5 feet in length and has two main functions: to absorb all remaining water from the food waste and to compress the remaining matter into a compact bundle (feces or stool) so that defecation (excretion of waste) is easy and convenient. The cecum is a short pouch containing a valve which opens to receive chyme from the ileum. The colon absorbs water and through bacterial action reduces the bulk of fiber in the feces. The rectum is the terminal segment of the digestive tract, in which feces accumulate just prior to discharge. They are discharged through the anus which contains two important muscles - the internal sphincter and the external sphincter. The internal sphincter is always tight, except when feces enter the rectum, in order to keep us continent (eg) when we are asleep. When we get an urge to defecate, we depend upon the external sphincter to keep the stool in until we go to the toilet. In total, it takes about 36-48 hours or longer for waste matter to pass through the large intestine. As in the esophagus and the small intestine, the contents of the large intestine are pushed forward by a sequence of muscular contractions called peristalsis (a type of motility or muscular movement). Peristalsis is regulated by a large network of nerves, hormones and muscles. Malfunction of any of these components may lead to a range of intestinal problems, including indigestion and constipation. For more, see Guide To Digestion In The Large Intestine.
Indigestion And Other Digestive Disorders
Bad eating habits - like over consumption of refined carbs, or lack of dietary fiber - can cause constipation, indigestion, nonulcer dyspepsia, or can lead to certain specific digestion-related conditions such as diverticulosis and Irritable Bowel Syndrome (IBS), or nutritional deficiencies. Other digestive disorders include candida, celiac disease and lactose intolerance. Viral infections can lead to diarrhea and gastroenteritis for which specific anti-diarrhea dietary treatment may be urgently required. Lastly, ingested food toxins can cause a number of unpleasant digestive complaints or even food poisoning. For more, see Diet Advice For Digestion Problems.
Guide to digestion of proteins
Why Protein Digestion Is So Important
An essential macronutrient, protein is used by the body to build and repair cells, to regulate a huge number of body functions. For example, almost 50 percent of the dietary protein we consume each day goes into making enzymes, the specialized proteins that help to digest food, assemble or divide molecules to make new cells and other chemical substances. Protein is also used to make neurotransmitters, essential for sending nerve messages around the body. Protein is also used in the creation of DNA and RNA, the nucleic acids responsible for determining how our body cells are formed and how they behave.
Protein Digestion In The Stomach
Enzymes are crucial contributors to protein digestion. Protein-digesting enzymes are referred to as proteinases or proteases. Protein generally takes the form of very complex molecules arranged in chains of amino acids. So the bonds binding these complex molecules together must first be broken down. This digestive process begins in the stomach, where hydrochloric acid, secreted in the stomach's gastric acid, attacks the protein molecules separating them and breaking them down into amino acids. Then the gastric enzyme pepsin - the only protease able to digest collagen (the fibrous protein found in animal connective tissue) - starts to digest the amino acids.
Protein Digestion In The Small Intestine
Digestion of proteins continues in the duodenum, the first segment of the small intestine. As in fat digestion, the pancreas helps the process by secreting the pancreatic protease enzymes trypsin and chymotrypsin. Like pepsin, trypsin breaks down a protein into single amino acid molecules, through a process called hydrolysis. During hydrolysis, a water molecule is inserted between the two amino acids which are bonded together. This breaks the bond between them. After breakdown, the amino acids are small enough to pass through the intestinal lining into tiny veins (capillaries) in the villi (the finger-like projections on the wall of the small intestine). Once in the bloodstream, the amino acids are distributed by both red blood cells and by the liquid blood plasma to tissues throughout the body where they are used in the creation and repair of cell structures. Such is the demand for protein, the body maintains a constant balance of amino acids in the blood.
Surplus Protein Calories In Diet
If protein requirements are exceeded by protein intake, the surplus amino acids may be converted to glucose for energy use, or converted to fatty acids and stored as adipose tissue.
Insufficient Protein In Diet
If we eat insufficient protein (not very likely for most people), the body may break down stored protein in the muscles and transport the amino acids to the more vital organs, as required. Alternatively, if our energy intake falls dangerously low, protein amino acids will be taken from the muscles and sent to the liver to be converted into glucose.
An essential macronutrient, protein is used by the body to build and repair cells, to regulate a huge number of body functions. For example, almost 50 percent of the dietary protein we consume each day goes into making enzymes, the specialized proteins that help to digest food, assemble or divide molecules to make new cells and other chemical substances. Protein is also used to make neurotransmitters, essential for sending nerve messages around the body. Protein is also used in the creation of DNA and RNA, the nucleic acids responsible for determining how our body cells are formed and how they behave.
Protein Digestion In The Stomach
Enzymes are crucial contributors to protein digestion. Protein-digesting enzymes are referred to as proteinases or proteases. Protein generally takes the form of very complex molecules arranged in chains of amino acids. So the bonds binding these complex molecules together must first be broken down. This digestive process begins in the stomach, where hydrochloric acid, secreted in the stomach's gastric acid, attacks the protein molecules separating them and breaking them down into amino acids. Then the gastric enzyme pepsin - the only protease able to digest collagen (the fibrous protein found in animal connective tissue) - starts to digest the amino acids.
Protein Digestion In The Small Intestine
Digestion of proteins continues in the duodenum, the first segment of the small intestine. As in fat digestion, the pancreas helps the process by secreting the pancreatic protease enzymes trypsin and chymotrypsin. Like pepsin, trypsin breaks down a protein into single amino acid molecules, through a process called hydrolysis. During hydrolysis, a water molecule is inserted between the two amino acids which are bonded together. This breaks the bond between them. After breakdown, the amino acids are small enough to pass through the intestinal lining into tiny veins (capillaries) in the villi (the finger-like projections on the wall of the small intestine). Once in the bloodstream, the amino acids are distributed by both red blood cells and by the liquid blood plasma to tissues throughout the body where they are used in the creation and repair of cell structures. Such is the demand for protein, the body maintains a constant balance of amino acids in the blood.
Surplus Protein Calories In Diet
If protein requirements are exceeded by protein intake, the surplus amino acids may be converted to glucose for energy use, or converted to fatty acids and stored as adipose tissue.
Insufficient Protein In Diet
If we eat insufficient protein (not very likely for most people), the body may break down stored protein in the muscles and transport the amino acids to the more vital organs, as required. Alternatively, if our energy intake falls dangerously low, protein amino acids will be taken from the muscles and sent to the liver to be converted into glucose.
Food habits
Reduce the "Damp-forming" foods
Returning to our theme of dampness in the system caused by the poor digestion. The "damp" forming foods are obviously the ones that should be removed. Most of you will be able to identify the main culprits - dairy and wheat. But there are others - bananas, concentrated orange and tomato juices, soy products, pork and rich meats, fats, bread, yeast, alcohol and sugars.
Reduce the "Cold" foods
Then there are the "cold" foods which include all food and drink that is taken cold or raw. An overload of damp and cold foods impairs the digestion. The Chinese have an energy equation where they measure the net amount of energy that is derived from a food after digestion. In other words, you subtract the amount of energy the body uses to bring the food to body temperature and digest it, from the total energy value of that food. Warm and easily digestible foods obviously will come out on top - they will deliver more net energy than cold, damp foods.
So the diet will rely heavily on vegetables cooked in their own juices and ripe fruits (they will not tax the system), and cereal grains and legumes for their energy and protein content. But the person with the poor digestion may be unable to tolerate grains and legumes, so how do we adjust to meet these requirements? We bring these foods down to a minimum (but observe cooking techniques - see later) and bring the vegetables up to a maximum - which means juicing. But isn't this increasing the content of cold and raw? You are right, except when you juice you are actually increasing the net energy of the food.
Include vegetable juices
Freshly prepared juices, strained so that there is no fibre, require very little digestion. Not only this, if you use a juicer that does not destroy the enzymes, and take the juice as soon as it is prepared (60% of enzymes die within 30 minutes), then the nutrients contained within the living enzymes are rapidly taken up by the body, particularly the sick tissues which have already lost their capacity to recycle, retain and utilize nutrients. These tissues are unable to reactivate their own enzyme systems and so by default, they perpetuate a state of nutritional deficiency, even if plied with chemical nutrients. However, nutrients in their living state will support and replenish the enzyme systems of the cells until such a point when the organs are sufficiently restored to take over their full function. Nutrients fall out of their living state when the enzymes die or are oxidized, and they are no longer as effective. Enzymes are only living when taken in the raw state of the vegetable or fruit, not freeze-dried or processed in any other way.
Observe Food Preparation/Cooking Techniques
Cooked foods, particularly the cereal grains and legumes, must be prepared properly to maximize their nutritional value. They may form only a small part of the diet; perhaps you will take an oat porridge for breakfast daily, and include brown rice and legumes three times weekly. Protein requirements can be made good through the volume of juicing and by taking small amounts of yoghurt, already partially digested through bacterial activity (sheep or goat is less damp-forming than cow's), preferably unpasteurized and organic.
The food preparation techniques for the seeds (nuts, grains and legumes are all seeds) are paramount to digestibility. It is the soaking, followed by the semi-germinating of these products that enables maximum digestion and absorption of nutrients. Soaking for at least 12 hours, inactivates phytic acid (very high in soy products) which binds with, and leads to heavy losses of dietary calcium, iron and zinc; while semi-germinating (rinse and drain the soaked seed and place in a glass bowl covered with a damp cloth for 12 hours) inactivates the enzyme inhibitors contained in all seeds. These inhibitors, which stop the seed from germinating until conditions are right, will inactivate your own digestive enzymes - hence the tremendous digestive difficulties people may experience with these products. I would recommend starting with lentils if your digestion is very poor.
So the diet is simple, it won't jam the system and it will allow the digestion to restore. I use very few supplements, as if we can get the body to unlock all the nutrients - both the discovered and undiscovered, in their correct composition, mixture and quantity - then what better medicine can you get. However, I do recommend digestive enzymes, and the poorer the digestion, the more we take. There are many to choose from, both plant and animal enzymes are available (the ones derived from animal sources tend to be more effective). The basic rule of thumb is that you take as many as required, that will alleviate digestive discomfort on this very simple diet. Charcoal is quite good for alleviating the gas. You can take some salads, as the digestion will allow, and remember, to take your juices fresh, to help to eliminate gas build-up.
Returning to our theme of dampness in the system caused by the poor digestion. The "damp" forming foods are obviously the ones that should be removed. Most of you will be able to identify the main culprits - dairy and wheat. But there are others - bananas, concentrated orange and tomato juices, soy products, pork and rich meats, fats, bread, yeast, alcohol and sugars.
Reduce the "Cold" foods
Then there are the "cold" foods which include all food and drink that is taken cold or raw. An overload of damp and cold foods impairs the digestion. The Chinese have an energy equation where they measure the net amount of energy that is derived from a food after digestion. In other words, you subtract the amount of energy the body uses to bring the food to body temperature and digest it, from the total energy value of that food. Warm and easily digestible foods obviously will come out on top - they will deliver more net energy than cold, damp foods.
So the diet will rely heavily on vegetables cooked in their own juices and ripe fruits (they will not tax the system), and cereal grains and legumes for their energy and protein content. But the person with the poor digestion may be unable to tolerate grains and legumes, so how do we adjust to meet these requirements? We bring these foods down to a minimum (but observe cooking techniques - see later) and bring the vegetables up to a maximum - which means juicing. But isn't this increasing the content of cold and raw? You are right, except when you juice you are actually increasing the net energy of the food.
Include vegetable juices
Freshly prepared juices, strained so that there is no fibre, require very little digestion. Not only this, if you use a juicer that does not destroy the enzymes, and take the juice as soon as it is prepared (60% of enzymes die within 30 minutes), then the nutrients contained within the living enzymes are rapidly taken up by the body, particularly the sick tissues which have already lost their capacity to recycle, retain and utilize nutrients. These tissues are unable to reactivate their own enzyme systems and so by default, they perpetuate a state of nutritional deficiency, even if plied with chemical nutrients. However, nutrients in their living state will support and replenish the enzyme systems of the cells until such a point when the organs are sufficiently restored to take over their full function. Nutrients fall out of their living state when the enzymes die or are oxidized, and they are no longer as effective. Enzymes are only living when taken in the raw state of the vegetable or fruit, not freeze-dried or processed in any other way.
Observe Food Preparation/Cooking Techniques
Cooked foods, particularly the cereal grains and legumes, must be prepared properly to maximize their nutritional value. They may form only a small part of the diet; perhaps you will take an oat porridge for breakfast daily, and include brown rice and legumes three times weekly. Protein requirements can be made good through the volume of juicing and by taking small amounts of yoghurt, already partially digested through bacterial activity (sheep or goat is less damp-forming than cow's), preferably unpasteurized and organic.
The food preparation techniques for the seeds (nuts, grains and legumes are all seeds) are paramount to digestibility. It is the soaking, followed by the semi-germinating of these products that enables maximum digestion and absorption of nutrients. Soaking for at least 12 hours, inactivates phytic acid (very high in soy products) which binds with, and leads to heavy losses of dietary calcium, iron and zinc; while semi-germinating (rinse and drain the soaked seed and place in a glass bowl covered with a damp cloth for 12 hours) inactivates the enzyme inhibitors contained in all seeds. These inhibitors, which stop the seed from germinating until conditions are right, will inactivate your own digestive enzymes - hence the tremendous digestive difficulties people may experience with these products. I would recommend starting with lentils if your digestion is very poor.
So the diet is simple, it won't jam the system and it will allow the digestion to restore. I use very few supplements, as if we can get the body to unlock all the nutrients - both the discovered and undiscovered, in their correct composition, mixture and quantity - then what better medicine can you get. However, I do recommend digestive enzymes, and the poorer the digestion, the more we take. There are many to choose from, both plant and animal enzymes are available (the ones derived from animal sources tend to be more effective). The basic rule of thumb is that you take as many as required, that will alleviate digestive discomfort on this very simple diet. Charcoal is quite good for alleviating the gas. You can take some salads, as the digestion will allow, and remember, to take your juices fresh, to help to eliminate gas build-up.
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