Agape Acupuncture

Over 45,000 Patients Treated

4th Generation in Natural Health

Treatment methods from the Emperor's Royal Physician of China's Qin Dynasty

Our family has been serving patients in the United States since 1980 and serving California for 30 years

Acupuncture and Herbal Medicine, Diet and Nutrition

Treatment of Difficult Diseases and PAIN

Natural Healing, Medicine & Well-Being

Our Patients include Doctors, Physicians (MD & Ph.D.), Nurses (RN), Chiropractors, Licensed Acupuncturists, Pastors, Post Graduates, and other Healthcare Professionals

MD Recommended

Acupuncture is FDA Approved
Painless, Safe and Gentle

We use DISPOSABLE needles only, guaranteed

Traditional Chinese Medicine

Supplements are Made in the U.S.A.

Great Results with Natural Medicine
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AGAPE ACUPUNCTURE
ORANGE COUNTY So.Cal

acupuncture, acupuncturist, herbal medicine, nutrition, food, diet, supplements
Dr. Kevin Huang, JD, NHD
    L.Ac., Dipl.Ac., Dipl.C.H.
Dr. Janet Marie Yeh
    Ph.D., M.Sc., L.Ac.

Psalm 118:8, Matthew 6:33
Gentle Loving Care

Read More About Us

4TH GENERATION IN NATURAL MEDICINE ACUPUNCTURE
714-979-9791
ACUPUNCTURE
HERBAL MEDICINE
NUTRITION & FOOD
DIETARY SUPPLEMENTS

We pledge to you our dedication to top quality medical excellence.
We are conveniently located off of the 405 freeway, by South Coast Plaza - in Orange County, California. We are at the corner of Fairview Road and MacArthur Blvd.

DISEASES TREATED

AUTO IMMUNE:
Rheumatoid Arthritis
Psoriatic Arthritis
Psoriasis, Lupus SLE
Graves' Disease
Crohn's Disease
Raynaud's Phenomenon
Hashimoto's Thyroiditis

DIGESTIVE DISORDERS:
GERD, IBS, Gastritis
Crohn's Disease
Colitis, Ulcerative Colitis
Chronic Diarrhea, Dysentery
Constipation,
Stomach & Abdominal Pain
Hemorrhoids, Bloody Stools

IMMUNE DISEASES:
Allergy, Sinusitis
Bronchitis, Asthma
Bladder & UTI Infections
Inflammation & Swelling
Viral Infections
Fungal Infections
Bacterial Infections

MOOD DISORDERS:
Panic Disorder, Panic Attack
Anxiety and Depression
Anger, Stress, Fear
Mood Swings, Moodiness

REPRODUCTIVE:
Infertility, Miscarriage
Natural Pregnancy
PMS, PCOS
Endometriosis
Hormonal Imbalance
Female System Care
Tumors & Cysts
Menopause, Hot Flashes
Sterility, ED
Male System Care

SKIN CONDITIONS:
Psoriasis, Eczema
Scaly, Itchy, Irritated Skin
Acne & Blemished Skin
Natural Face Lift
Sagging Skin, Wrinkles
Dermatitis, Inflammation
Hives (Urticaria)
Insect Bites

DIFFICULT DISEASES:
Hypertension (HBP)
High Cholesterol
Diabetes, Hypoglycemia
Phlebitis, Thrombosis
Thyroid Disorders
Hyper- or Hypothyroidism
Liver Diseases, Hepatitis
Liver Fibrosis & Cirrhosis
Neuralgia, Neuropathy
Chronic Severe Pain

SCHEDULE AN APPOINTMENT 714-979-9791
SCHEDULE AN APPOINTMENT

If you have a specific illness or if you have questions, schedule an appointment for an individualized consultation. Your treatment plan and progress are monitored by a qualified and experienced medical professional. Our natural medicine treatments are personalized and tailored for your body's needs. Call 714-979-9791 to schedule an appointment today.


NATURAL HEALTH ORANGE COUNTY
NATURAL HEALTH
ORANGE COUNTY
Agape Acupuncture, Inc.

2781 W. MacArthur Blvd
Suite G-3
Santa Ana, CA 92704
South Coast Market Place

Call: 714-979-9791
Call: 714-979-9790
Fax: 714-333-9317
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Acquisition of Nutrition - Through Food

NUTRITIONAL NEEDS OF THE BODY
"
Each day, normal cell functioning must be maintained, damaged cells need to be repaired,
and new cells are generated. These things cannot occur without proper nutrients.
"

       

THE SCIENCE OF NUTRITION


FOOD

Nutrition is the vital chemical components needed daily by the body, which can be acquired in one of three ways: either 1)through foods, 2)through supplements, and in certain circumstances, even 3)intravenously. The most commonly practiced method is through the consumption of food.

Food is an excellent method to take in nutrients. The body is fully equipped to ingest food into the body, digest it into smaller components, absorb food to utilize in cellular mechanisms, and excrete the waste products. In a healthy person, this chain of events occurs daily and is both natural and normal. It is safe to conclude that the human body cannot survive without food and nutrition. Food is very important to both the plant and animal kingdoms, and it is essential to life. It is used by people of different background, race, age, gender, culture, education level, and economic level. If the body does not get food, many problems will arise, such as hunger, weakness, deterioration of the body, imbalance of organs, cessation of normal bodily functions and even death.  Food is required and consumed by all.

But what is food? What is in the food that makes it so important? What happens to the food once it enters the mouth? What is digestion and metabolism? How does food fuel the body? What do words like "amino acids" and "carbohydrates" really mean? What would happen if we only ate meat for a whole week? Why can't we eat grass like cows or wood like termites? These are all legitimate questions that deserve correct answers, because this knowledge applies to each and every one of us. The journey each distinct component of food takes as it enters the human body and gets digested is important to all of us. Even though human metabolism and digestion is a complex event, in a healthy person, it is also extremely consistent and reliable – like clockwork.

The Basics of Food

Think about some of the foods people consume everyday: cereal, oatmeal, bread, rice, milk, juice, egg, ham, cheese, an apple, potatoes, carrot, peanut butter etc. These are all called foods, and they contain seven basic components: 1) Carbohydrates, 2) Proteins, 3) Fats, 4) Vitamins, 5) Minerals, 6) Fiber, and 7) Water. Once it enters the mouth, it is the body job to digest, absorb, assimilate, metabolize, and use the key components to keep the body alive. Each of these key ingredients is important and plays an individualized and specific role.

In the following sections, each of these basic components will be broken down and analyzed in order to understand what they really do and why they are so important for the body. Note that there might be "non-food" items mixed in with what is consumed, especially if the diet consists of a lot of processed foods. Things like artificial colors, artificial flavors and chemical preservatives are the most common. These are synthetic additives and are not part of the natural foods.

Carbohydrates

The term, carbohydrates and complex carbohydrates, should be familiar terms. Carbohydrates provide the body with its basic fuel, similar to gasoline for an automobile engine. The simplest carbohydrate is glucose. Glucose, also called "blood sugar" and "dextrose", flows in the bloodstream so that it is available to every cell in the body. The cells absorb glucose and convert it into energy to drive normalized bodily functions. 

A set of chemical reactions on glucose, called glycolysis, generates ATP (adenosine triphosphate). A phosphate bond in ATP powers human intracellular mechanisms. Therefore, if a solution of plain water and glucose is consumed, the glucose will pass directly from the digestive system and be absorbed into the bloodstream. The quick integration of simple carbohydrates into the bloodstream causes the pH within the blood system to shift to a more acidic level, and the blood sugar becomes elevated. Too high of an elevation of blood sugar is termed hyperglycemia, and this condition if prolonged leads to diabetes. On the converse, if not enough carbohydrates enter the bloodstream, the pH shifts to a more alkaline environment and the blood sugar becomes lowered. This lack of blood sugar is called hypoglycemia.

The word "carbohydrate" comes from the composition of glucose, which is made up of carbon and water.

1) Glucose: The basic chemical formula for glucose is C6H12O6, which was learned in general chemistry. Glucose is made of 6 carbon atoms "carbo" and the elements of 6 water molecules "hydrate". The simple sugar, glucose, is a monosaccharide carbohydrate. To the tongue, it tastes sweet.

2) Fructose: The simple sugar fructose is a monosaccharide carbohydrate and is the main sugar found in fruits. Fructose has the same chemical formula as glucose (C6H12O6), but the atoms are arranged slightly differently. The liver converts fructose to glucose.

3) Galactose: The monosaccharide carbohydrate, galactose, like fructose, has the same chemical components as glucose, but the atoms are arranged differently. The liver also converts the galactose to glucose.

4) Sucrose: Another familiar simple sugar is sucrose, also known as white sugar or table sugar. Sucrose is a disaccharide carbohydrate made up of one glucose and one fructose molecule bonded together.

5) Lactose: This simple sugar, lactose, is a disaccharide carbohydrate found in milk and is made up of one glucose and one galactose molecule bonded together.

6) Maltose: The simple sugar maltose is a disaccharide carbohydrate found in malt and is made from two glucose atoms bonded together.

Glucose, fructose and galactose are monosaccharides and are the only carbohydrates that can be absorbed into the bloodstream through the intestinal lining. Lactose, sucrose and maltose are disaccharides, meaning they contain two monosaccharides. These simple sugars are easily converted to their monosaccharide bases by enzymes in the digestive tract. Monosaccharides and disaccharides are called simple carbohydrates, so they are digested quickly and enter the bloodstream quickly. They are all sugars, which means they all taste sweet to the tongue. On the "Nutrition Facts" label on a food package, it is very common to find "sugars" under the term "carbohydrates". These six simple sugars are what the label is talking about.

There are also complex carbohydrates, commonly known as starches. A complex carbohydrate is made up of chains of glucose molecules. Starches are the manner in which plants store energy. Plants produce glucose and chain the glucose molecules together to form starch. Most grains, such as wheat, corn, oat and rice, and foods, such as potatoes and plantains are high in starch. When consumed, the digestive system breaks a complex carbohydrate (starch) back down into glucose molecules. The glucose can then enter the bloodstream.

Starches take a longer time to break down than simple sugars. If someone drinks a can of soda full of sugar, glucose will enter the bloodstream at a rate of 30 calories per minute. A complex carbohydrate, rice for example, is digested more slowly, so glucose enters the bloodstream at a rate of only 2 calories per minute. Therefore, eating complex carbohydrates is a good thing and eating sugar is a bad thing.

"The Yale Guide to Children's Nutrition" addresses the question: if complex carbohydrates are broken down to monosaccharides in the intestines before they are absorbed into the bloodstream, why are they better than refined sugar or other di- or mono- saccharides? To a great extent, it has to do with the processes of digestion and absorption. Simple sugars require little digestion, and when a child eats a sweet food, such as a candy bar or a can of soda, the glucose level of the blood rises rapidly. In response, the pancreas secretes a large amount of insulin to keep blood glucose levels from rising too high.

This large insulin response, in turn, tends to make the blood sugar fall to levels that are too low 3 to 5 hours after the candy bar or can of soda has been consumed. This tendency of blood glucose levels to fall may then lead to an adrenaline surge, which in turn can cause nervousness and irritability. The same roller-coaster ride of glucose and hormone levels is not experienced after eating complex carbohydrates or after eating a balanced meal because the digestion and absorption processes are much slower.

Thinking about this concept is incredibly interesting, because this means that foods and the manner in which they are consumed can affect mood and temperament. They do so by affecting the levels of different hormones in the bloodstream over time. Another interesting thing about this quote is the mention of insulin. It turns out that insulin is incredibly important to the way the body uses glucose that foods provide. The functions of insulin are: 1) to enable glucose to be transported across cell membranes, 2) to convert glucose into glycogen for storage in the liver and muscles, 3) to help excess glucose be converted into fat, and 4) to prevent protein breakdown for energy.

Insulin is a simple protein in which two polypeptide chains of amino acids are joined by disulfide linkages. Insulin helps transfer glucose into cells so that they can oxidize the glucose to produce energy for the body. In adipose tissue, insulin facilitates the storage of glucose and its conversion to fatty acids. Insulin also slows the breakdown of fatty acids. In muscle it promotes the uptake of amino acids for making proteins. In the liver it helps convert glucose into glycogen, the storage carbohydrate, and it decreases gluconeogenesis, the formation of glucose from non-carbohydrate sources. The action of insulin is opposed by glucagon, another pancreatic hormone, and by epinephrine.

From the above description, there are a lot of different things happening within the body having to do with glucose. Because glucose is the essential energy source, the body has many different mechanisms to ensure that the right level of glucose is flowing in the bloodstream. For example, the body can store glucose in the liver as glycogen and also convert protein to glucose when needed. Therefore, carbohydrates are important to the body because they provide the energy that cells need to survive.

Proteins

A protein is a chain of amino acids. An amino acid is a small molecule that acts as the building block of each and every cell. Carbohydrates provide cells with energy, while amino acids provide cells with the building material needed to grow and maintain structure. The body consists of approximately 20% protein by weight.

These small molecules are called "amino acids" because they all contain an amino group (NH2) and a carboxyl group (COOH), which is acidic. The top parts of amino acids are identical. The chain at the bottom is the only thing varying from one amino acid to the next. In some amino acids the variable part can be quite large. The human body is constructed of 22 different amino acids, and there are roughly 100 different amino acids available in nature. As far as the body is concerned, there are two different types of amino acids: essential and non-essential. Non-essential amino acids are amino acids that the body can create out of other chemicals found in your body. Essential amino acids cannot be created, and therefore the only way to get them is through food.

Protein in the diet comes from both animal and vegetable sources. Sources, such as soy, spirulina, meat, milk and eggs provide "complete protein", meaning that they contain all of the essential amino acids. Some vegetable sources contain quite a bit of protein, such as nuts, beans; soybeans are all high in protein. Certain sources are sometimes low or missing certain essential amino acids. For example, rice is low in isoleucine and lysine. In order to complement deficiencies of different amino acids, by combining different foods all of the essential amino acids will be attained throughout the course of a day. The digestive system breaks all proteins down into amino acids to facilitate their entrance into the bloodstream. Cells then use the amino acids as building blocks, therefore, the body needs protein and cannot survive strictly on carbohydrates.

Fats

Most people are familiar regarding common fats that different foods contain. Meat contains animal fat. Most breads and pastries contain vegetable oils, shortening or lard. Deep fried foods are cooked in heated oils. Fats are greasy and slick. Commonly, there are two main kinds of fats: saturated and unsaturated. Saturated fats are normally solid at room temperature while unsaturated fats are liquid at room temperature.

Vegetable oils are the best examples of unsaturated fats while lard, shortening, and animal fats are saturated fats. However, most fats contain a mixture. For example, the label on a bottle of olive oil states that it contains both saturated and unsaturated fats. But the saturated fats are dissolved in the unsaturated fats. To separate them, put olive oil in the refrigerator. The saturated fats will solidify and the unsaturated fats will remain liquid. There is even a further distinction of unsaturated fats between polyunsaturated and monounsaturated.

Fats that are consumed enter the digestive system and meet with an enzyme called lipase. Lipase breaks the fat into its parts: glycerol and fatty acids. These components are then reassembled into triglycerides for transport in the bloodstream. Muscle cells and fat, or adipose, cells absorb the triglycerides either to store them or to burn them as fuel. The benefits of fat are: 1) Certain vitamins are fat-soluble. The only way to get these vitamins is to eat fat. 2) In the same way that there are essential amino acids, there are essential fatty acids (for example, Linoleic acid used to build cell membranes). They must also be obtained from the diet because the body has no way to make them. 3) Fat turns out to be a good source of energy. Fat contains twice as many calories per gram as carbohydrates or proteins. The body can burn fat as fuel when necessary.

Vitamins

The Merriam-Webster Dictionary defines vitamin as “any of various organic substances that are essential, in minute quantities, to the nutrition of most animals and some plants. They may act as coenzymes and precursors of coenzymes in the regulation of metabolic processes but do not provide energy or serve as building units, and are present in natural foodstuffs or sometimes produced within the body.” Vitamins are small molecules that the body needs to keep it running properly. Vitamin B-12 is the largest, with a molecular weight of 1,355. With the exception of Vitamin D, vitamins must be provided in food. The human body needs 13 different vitamins for survival:

        Vitamin A (Fat soluble, Retinol)  - comes from beta-carotene in plants - when beta-carotene is consumed, an enzyme in the stomach turns it into vitamin A.

        Vitamin B1: Thiamine (Water soluble)

        Vitamin B2: Riboflavin (Water soluble)

        Vitamin B3: Niacin (Water soluble)

        Vitamin B6: Pyridoxine (Water soluble)

        Vitamin B12: Cyanocobalamin (Water soluble)

        Folic Acid (Water soluble)

        Vitamin C (Water Soluble, Ascorbic Acid)

        Vitamin D (Fat Soluble, calciferol)

        Vitamin E (Fat soluble, tocopherol)

        Vitamin K (Fat Soluble, Menaquinone)

        Pantothenic Acid (Water soluble)

        Biotin (Water soluble)

In most cases, the lack of a vitamin causes severe problems. A diet of fresh, natural food usually provides all of the vitamins that you need. Processing tends to destroy vitamins; so many processed foods are "fortified" with man-made vitamins. The following list shows diseases associated with the lack of different vitamins:

        Lack of Vitamin A: Night blindness, xerophthalmia

        Lack of Vitamin B1: Beriberi

        Lack of Vitamin B2: problems with lips, tongue, skin,

        Lack of Vitamin B3: Pellagra

        Lack of Vitamin B12: Pernicious anemia

        Lack of Vitamin C: Scurvy

        Lack of Vitamin D: Rickets

        Lack of Vitamin E: malabsorption of fats, anemia

        Lack of Vitamin K: poor blood clotting, internal bleeding

Minerals

            Minerals are elements that the body must have in order to create specific molecules needed within the body. Some minerals are supplied in the molecule that uses them. For example, sulfur comes via the amino acid methionine and cobalt comes in as part of vitamin B12. Food provides these minerals, and if they are lacking in the diet, then various problems and diseases will arise. The common minerals needed by the body are calcium, chlorine, chromium, copper, fluorine, iodine, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, and zinc.

Water

The body is about 60% water. A person at rest loses about 40 ounces of water per day. Water leaves the body through the urine, sweat and skin and through the breath during exhalation. Obviously while working, exercising and sweating hard, the body can lose much more water. Because the body loses water all the time, it must be replaced. It is recommended to take in 64-80 fl. oz. of water per day through moist foods and liquids. In hot weather and when exercising, the body may need up to twice that amount. Many foods contain a surprising amount of water, especially fruits. Pure water and drinks provide the rest.

Fiber

            Fiber is the broad name given to the things consumed that the body cannot digest. The three fibers eaten on a regular basis are cellulose, hemicellulose and pectin. Hemicellulose is found in the hulls of different grains like wheat. Bran is hemicellulose. Cellulose is the structural component of plants. It gives a vegetable its familiar shape. Pectin is found most often in fruits, and is soluble in water but non-digestible. Pectin is normally called "water-soluble fiber" and forms a gel.

Cellulose is a complex carbohydrate. It is a chain of glucose molecules. Some animals and insects can digest cellulose. Both cows and termites have no problem with it because they have bacteria in their digestive systems secreting enzymes that break down cellulose into glucose. Human beings have neither the enzymes nor these beneficial bacteria, so cellulose is fiber or “roughage”.

When fiber enters the body, it simply passes straight through, untouched by the digestive system. However, fiber has an important role to maintain normal digestive function. It benefits normal bowel function, diverticular diseases, colon cancer, irritable bowel syndrome, heart disease, diabetes and weight control. Nutrition researchers and medical professionals are reevaluating the benefits of fiber and are stressing the importance of consuming fiber as a part of the daily diet.

Physiology of Starvation

A normal person who is eating three meals a day and snacking between meals gets almost all of his/her energy from glucose that carbohydrates provide. What happens when the body stops eating? What if a person is lost in the woods or is purposefully fasting? What does the body do for energy? The body goes through several phases in the attempt to keep the person alive during the absence of food.

The first line of defense against starvation is the liver. The liver stores glucose by converting it to glycogen. It holds approximately a 12-hour supply of glucose in the form of glycogen. Once the digesting of all the carbohydrates from the most recent meal is complete, the liver starts converting stored glycogen back into glucose and releases it to maintain glucose in the blood. Lipolysis also starts breaking down fat in the fat cells and releasing fatty acids into the bloodstream. Tissues that do not need to use glucose for energy, for example muscle cells, start burning the fatty acids. This reduces the glucose demand so that the nerve cells get glucose.

Once the liver runs out of glycogen, the liver converts to a process called gluconeogenesis. Gluconeogenesis turns amino acids into glucose. The liver then begins producing ketone bodies from fatty acids being made available in the blood by lipolysis. Brain and nerve cells convert over from being pure consumers of glucose to partial consumers of ketone bodies for energy.

Some of these alternative metabolic processes are actually used on a regular basis. For example, Eskimos eating a traditional Eskimo diet have virtually no carbohydrates on the menu. Also, several recent weight-loss programs try to take advantage of ketone metabolism to "burn fat".

So how does the body know that it is time to eat? Where does the sense of hunger come from? It's not from a rumbling stomach because people who have their stomachs removed still feel hungry. It appears that a small brain structure called the hypothalamus is the center of hunger. If one part of the hypothalamus is damaged, a person will overeat tremendously. If another part is damaged, a person never gets hungry. So clearly these two parts balance one another to produce the sense of hunger.

Digestion

Digestion is the process of breaking large molecules into smaller molecules by chemical and physical means so that the body can use them. The digestive tract, which is also known as the alimentary canal, is a long tube extending from the mouth to the anus.  This muscular tube is about nine meters long and it passes through the body’s ventral cavity. It is composed of the mouth, pharynx, esophagus, stomach, small intestines, and large intestines.  Along the alimentary canal are various glands, which secrete substances that contribute to the process of digestion. 

The alimentary canal is comprised of four layers, which are the mucosa, submucosa, muscular layer and serosa. The mucosa or mucous membrane is composed of epithelium, connective tissue and smooth muscle. This first layer protects the tissue beneath while absorbing nutrients and secreting digestive enzymes and mucous. The submucosa is made up of loose connective tissue as well as blood vessels, lymphatic vessels, glands and nerves. This layer nourishes the surrounding tissue and helps transport absorbed materials. The muscular layer is composed of smooth muscle fibers arranged in circular and longitudinal groups and is mainly responsible for providing the movements of the tube and its contents. The fourth layer is the serosa, which consists of epithelium and connective tissue and its function is for protection and lubrication.

Digestion starts when food is chewed in the mouth.  Chewing breaks up food so that it has more exposed surface area.  The tongue moves food under the teeth so that it can be chewed.  The tongue has taste buds, which convey information to the brain about the food.  It also aids in the process of swallowing foods.  The act of chewing is called mastication.

Salivary glands supply the mouth with a liquid substance called saliva. Saliva moistens and lubricates food so that it can be more easily chewed and swallowed.  It also dissolves some of the food so that it can be tasted.  Saliva has a pH of 6.7, making it slightly acidic.  Although saliva is 99% water, it also contains a digestive enzyme called salivary amylase, which helps to digest starch. 

There are three pairs of salivary glands. The largest pair is the parotid gland, which lie just in front of, and slightly below the opening of the ears. The parotid salivary glands become infected and enlarged when one has the mumps. Below the parotid salivary glands, near the angle of the lower jaw, are the submaxillary salivary glands. Under the sides of the tongue are the sublingual salivary glands.  If our body becomes dehydrated, the body draws water from the salivary glands to replace that which is lost from the blood through sweating.  Therefore, when we are thirsty (dehydrated) our mouth is dry from the lack of saliva.  Mastication in the presence of saliva changes food into a ball of food called a bolus. 

The act of swallowing starts as a voluntary process involving muscles in the mouth and pharynx, but becomes an involuntary process as the food comes under the control of the smooth muscles of the esophagus. As the swallowing process takes place, the bolus passes from the mouth to the pharynx. The pharynx is a region shared by both the digestive and respiratory systems.  The uvula, a small flap of tissue which hangs from the back of the mouth, prevents food from entering the nasal cavity.  Also in the pharynx, the epiglottis covers the windpipe so that the bolus cannot enter the lungs. When swallowing, the part of the nervous system responsible for breathing is inhibited, so that it is almost impossible to breathe and swallow at the same time. This also serves to prevent food from entering the respiratory system. 

The bolus is taken down the esophagus by a series of involuntary muscular movements known as “peristalsis”.  Lining the esophagus are cells, which produce mucus. The mucus lubricates the esophagus to allow the bolus to pass with less friction. The continued muscular contractions of peristalsis occur behind the bolus so that it is pushed toward the stomach. At the point where the esophagus meets the stomach is a value called the cardiac sphincter. When the peristaltic wave reaches the cardiac sphincter, the sphincter opens to allow the bolus to pass into the stomach. Then it closes. It is the cardiac sphincter that prevents food from coming back into the esophagus when one, for example, does a cartwheel or stands on the head. 

The stomach lies to the left of and just below the diaphragm.  The capacity of the average stomach is a little over a quart.  The internal lining of the stomach is called the “gastric mucosa”.  The gastric mucosa contains long tubular gastric glands that secrete the gastric juices used in digestion.  About 35,000 of these glands line the normal stomach.  The gastric glands have three different types of cells, which secrete three different substances.  The parietal cells secrete hydrochloric acid, the chief cells secrete pepsinogen, and the mucous neck cells secrete mucin. 

Hydrochloric acid (HCL) causes the acidity of gastric juice to be in the range of pH 1 to pH 3. (pH is the negative logarithm of the hydrogen ion concentration. A complete definition requires that the logarithm be defined as being to the base ten and the concentration to be measured as activity in moles per liter. When stomach acid increases, then the pH will decrease. Neutral is the pH at which there are equal numbers of [H+] ions and [OH-] ions. Water is more ionized at body temperature than at room temperature; neutral is pH 6.8 rather than 7.0. This is also the average pH inside the cell. The body preserves neutrality (pH 6.8) inside our cells, where most of the body's chemistry occurs, and maintains the blood at pH 7.4, which is 0.6 pH units on the alkaline side of.)

The hydrochloric acid of the stomach practically guarantees that any bacteria ingested with food will be destroyed.  The few that are not destroyed can in some cases cause food poisoning.  Hydrochloric acid combines with pepsinogen to form the enzyme called pepsin.  Pepsin digests only protein.  Mucin is a secretion, which protects the stomach from being dissolved by the hydrochloric acid. The presence of the acid producing bacteria H. pylori, increases the acidity of the stomach so that the stomach lining is dissolved.  This condition is called a peptic ulcer.  The quantity of gastric juices secreted to digest an average meal is a little over a half-quart.

Within the walls of the stomach are muscular contractions and waves, which move the food about. As in the esophagus, this muscular action is referred to as peristalsis.  This muscular action combined with the digestive action of gastric juices convert the food into a thick liquid called a chyme. Under certain conditions, the normal path of the peristaltic wave is reversed to produce vomiting. The region of the nervous system, which triggers vomiting, is in a part of the brain stem called the medulla oblongata.

At the bottom of the stomach is the pyloric sphincter. When it opens it releases the chyme into the first part of the small intestines called the duodenum, a region which is wider that the rest of the small intestines. The glands of the small intestines secrete large quantities of alkaline mucus, which is unlike the highly acidic gastric juice produced by the stomach.

The liver and the pancreas also pour digestive juices into the duodenum. The digestive juice produced by the liver is called bile, and it is made in the liver from the worn out hemoglobin of red blood cells.  When bile is not needed for digestion, it is stored in the gall bladder.  Bile is a base that digests fats.  The digestive part of the pancreas produces pancreatic juice, which is an enzyme that digests protein, fat and carbohydrates. Another part of the pancreas produces insulin, the hormone that transports sugar across the cell membrane.  If insulin is not produced, a disease called diabetes mellitus results. However, insulin is not involved in the digestion process in the small intestines.

The digestion of chyme is completed by intestinal enzymes and then passed into the blood stream. As the peristaltic wave continues, the digested food and waste pass through the circular folds of the small intestines, which have small finger-like projections called villi.  The capillaries of the villi absorb the digested food into the blood steam.

The waste products of digestion move on by way of peristaltic contraction into the large intestines, which is also called the colon.  The large intestines separate water from waste and allow the reabsorption of water into the body.  No digestion occurs in the large intestines.  In the large intestines are large colonies of bacteria that act on the undigested waste and convert these into gases, acids, vitamins, and waste. 

The reabsorption of water and the action of bacteria change the consistency of the intestinal contents from a liquid to a semisolid called feces.  Feces are composed of bacteria, waste products brought by blood, products of the action of bacteria in the intestines, salts, mucus, and the indigestible components of food, such as cellulose.  The indigestible parts of food, such as cellulose, are called fiber. Fiber stimulates the lining of the intestines to induce peristalsis and the opening of the anal sphincter, which allows the elimination of feces from the body.

A part of the large intestines is a small projection called the appendix. This can occasionally become infected and inflamed by bacteria and rupture. The bacteria of the large intestines rush into the body cavity from a ruptured appendix.  Since the body cavity has few blood vessels, white blood cells cannot be delivered quickly enough to prevent massive bacterial infection of the body cavity.  The quicker this rupture can be closed, the better the chance to avoid extensive infection and even death.  Severe inflammation and rupture of the appendix is known as appendicitis.

The small intestines are about 25 feet long. The large intestines are about five feet long. The small intestines are called "small" because its diameter is smaller than that of the large intestines.  Conversely, the large intestines are called "large" because its diameter is larger than that of the small intestines.