HUMAN DIGESTIVE SYSTEM. DIGESTIVE SYSTEM DIGESTION PROCESS The start of the process - the mouth: The digestive process begins in the mouth. Food is partly.

HUMAN DIGESTIVE HUMAN DIGESTIVE SYSTEMSYSTEM

DIGESTIVE SYSTEMDIGESTIVE SYSTEM

DIGESTION PROCESSDIGESTION PROCESS

The start of the process - the mouthThe start of the process - the mouth:: The The digestive process begins in the mouth. Food is digestive process begins in the mouth. Food is partly broken down by the process of chewing partly broken down by the process of chewing and by the chemical action of salivary enzymes and by the chemical action of salivary enzymes (these enzymes are produced by the salivary (these enzymes are produced by the salivary glands and break down starches into smaller glands and break down starches into smaller molecules). molecules).

On the way to the stomach: the esophagus - After being chewed and swallowed, the food enters the esophagus. The esophagus is a long tube that runs from the mouth to the stomach. It uses rhythmic, wave-like muscle movements (called peristalsis) to force food from the throat into the stomach. This muscle movement gives us the ability to eat or drink even when we're upside-down

•In the stomach - The stomach is a large, sack-like organ that churns the food and bathes it in a very strong acid (gastric acid). Food in the stomach that is partly digested and mixed with stomach acids is called chyme.

•In the small intestine - After being in the stomach, food enters the duodenum, the first part of the small intestine. It then enters the jejunum and then the ileum (the final part of the small intestine). In the small intestine, bile (produced in the liver and stored in the gall bladder), pancreatic enzymes, and other digestive enzymes produced by the inner wall of the small intestine help in the breakdown of food.

•In the large intestine - After passing through the small intestine, food passes into the large intestine. In the large intestine, some of the water and electrolytes (chemicals like sodium) are removed from the food. Many microbes (bacteria like Bacteroides, Lactobacillus acidophilus, Escherichia coli, and Klebsiella) in the large intestine help in the digestion process. The first part of the large intestine is called the cecum (the appendix is connected to the cecum). Food then travels upward in the ascending colon. The food travels across the abdomen in the transverse colon, goes back down the other side of the body in the descending colon, and then through the sigmoid colon.

•The end of the process - Solid waste is then stored in the rectum until it is excreted via the anus.

ABSORPTION AND TRANSPORT ABSORPTION AND TRANSPORT OF NUTRIENTSOF NUTRIENTS

Digested molecules of food, as well as water and Digested molecules of food, as well as water and minerals from the diet, are absorbed from the minerals from the diet, are absorbed from the cavity of the upper small intestine. Most absorbed cavity of the upper small intestine. Most absorbed materials cross the mucosa into the blood and are materials cross the mucosa into the blood and are carried off in the bloodstream to other parts of carried off in the bloodstream to other parts of the body for storage or further chemical changethe body for storage or further chemical change

The digestible carbohydrates are broken into simpler molecules by enzymes in the saliva, in juice produced by the pancreas, and in the lining of the small intestine. Starch is digested in two steps: First, an enzyme in the saliva and pancreatic juice breaks the starch into molecules called maltose; then an enzyme in the lining of the small intestine (maltase) splits the maltose into glucose molecules that can be absorbed into the blood. Glucose is carried through the bloodstream to the liver, where it is stored or used to provide energy for the work of the body.

ProteinProtein.. Foods such as meat, eggs, and beans Foods such as meat, eggs, and beans consist of giant molecules of protein that must be consist of giant molecules of protein that must be digested by enzymes before they can be used to digested by enzymes before they can be used to build and repair body tissues. An enzyme in the build and repair body tissues. An enzyme in the juice of the stomach starts the digestion of juice of the stomach starts the digestion of swallowed protein. Further digestion of the protein swallowed protein. Further digestion of the protein is completed in the small intestine. Here, several is completed in the small intestine. Here, several enzymes from the pancreatic juice and the lining of enzymes from the pancreatic juice and the lining of the intestine carry out the breakdown of huge the intestine carry out the breakdown of huge protein molecules into small molecules called amino protein molecules into small molecules called amino acids. These small molecules can be absorbed from acids. These small molecules can be absorbed from the hollow of the small intestine into the blood and the hollow of the small intestine into the blood and then be carried to all parts of the body to build the then be carried to all parts of the body to build the walls and other parts of cells.walls and other parts of cells.

FatsFats.. Fat molecules are a rich source of energy for Fat molecules are a rich source of energy for the body. The first step in digestion of a fat such as the body. The first step in digestion of a fat such as butter is to dissolve it into the watery content of the butter is to dissolve it into the watery content of the intestinal cavity. The bile acids produced by the liver intestinal cavity. The bile acids produced by the liver act as natural detergents to dissolve fat in water and act as natural detergents to dissolve fat in water and allow the enzymes to break the large fat molecules allow the enzymes to break the large fat molecules into smaller molecules, some of which are fatty acids into smaller molecules, some of which are fatty acids and cholesterol. The bile acids combine with the and cholesterol. The bile acids combine with the fatty acids and cholesterol and help these molecules fatty acids and cholesterol and help these molecules to move into the cells of the mucosa. In these cells to move into the cells of the mucosa. In these cells the small molecules are formed back into large the small molecules are formed back into large molecules, most of which pass into vessels (called molecules, most of which pass into vessels (called lymphatics) near the intestine. These small vessels lymphatics) near the intestine. These small vessels carry the reformed fat to the veins of the chest, and carry the reformed fat to the veins of the chest, and the blood carries the fat to storage depots in the blood carries the fat to storage depots in different parts of the body.different parts of the body.

VitaminsVitamins.. Another vital part of our food Another vital part of our food that is absorbed from the small intestine is that is absorbed from the small intestine is the class of chemicals we call vitamins. the class of chemicals we call vitamins. The two different types of vitamins are The two different types of vitamins are classified by the fluid in which they can be classified by the fluid in which they can be dissolved: water-soluble vitamins (all the B dissolved: water-soluble vitamins (all the B vitamins and vitamin C) and fat-soluble vitamins and vitamin C) and fat-soluble vitamins (vitamins A, D, and K).vitamins (vitamins A, D, and K).

HOW IS THE DIGESTIVE HOW IS THE DIGESTIVE PROCESS CONTROLLED?PROCESS CONTROLLED?

The hormones that control digestion are gastrin, The hormones that control digestion are gastrin, secretin, and cholecystokinin (CCK):secretin, and cholecystokinin (CCK):

GastrinGastrin causes the stomach to produce an acid for causes the stomach to produce an acid for dissolving and digesting some foods. It is also dissolving and digesting some foods. It is also necessary for the normal growth of the lining of the necessary for the normal growth of the lining of the stomach, small intestine, and colon.stomach, small intestine, and colon.

SecretinSecretin causes the pancreas to send out a digestive causes the pancreas to send out a digestive juice that is rich in bicarbonate. It stimulates the juice that is rich in bicarbonate. It stimulates the stomach to produce pepsin, an enzyme that digests stomach to produce pepsin, an enzyme that digests protein, and it also stimulates the liver to produce bile.protein, and it also stimulates the liver to produce bile.

CCKCCK causes the pancreas to grow and to produce the causes the pancreas to grow and to produce the enzymes of pancreatic juice, and it causes the enzymes of pancreatic juice, and it causes the gallbladder to empty.gallbladder to empty.

NERVE REGULATORSNERVE REGULATORS

Two types of nerves help to control the action of Two types of nerves help to control the action of the digestive system. Extrinsic (outside) nerves the digestive system. Extrinsic (outside) nerves come to the digestive organs from the unconscious come to the digestive organs from the unconscious part of the brain or from the spinal cord. They part of the brain or from the spinal cord. They release a chemical called acetylcholine and release a chemical called acetylcholine and another called adrenaline. Acetylcholine causes another called adrenaline. Acetylcholine causes the muscle of the digestive organs to squeeze with the muscle of the digestive organs to squeeze with more force and increase the "push" of food and more force and increase the "push" of food and juice through the digestive tract. Acetylcholine also juice through the digestive tract. Acetylcholine also causes the stomach and pancreas to produce more causes the stomach and pancreas to produce more digestive juice. Adrenaline relaxes the muscle of digestive juice. Adrenaline relaxes the muscle of the stomach and intestine and decreases the flow the stomach and intestine and decreases the flow of blood to these organs.of blood to these organs.

Even more important, though, are the intrinsic Even more important, though, are the intrinsic (inside) nerves, which make up a very dense (inside) nerves, which make up a very dense network embedded in the walls of the esophagus, network embedded in the walls of the esophagus, stomach, small intestine, and colon. The intrinsic stomach, small intestine, and colon. The intrinsic nerves are triggered to act when the walls of the nerves are triggered to act when the walls of the hollow organs are stretched by food. They release hollow organs are stretched by food. They release many different substances that speed up or delay many different substances that speed up or delay the movement of food and the production of the movement of food and the production of juices by the digestive organs.juices by the digestive organs.

DIGESTIVE DISORDERSDIGESTIVE DISORDERS

The inflammation of the intestinal tract is The inflammation of the intestinal tract is the most common ailment due to bacterial the most common ailment due to bacterial or viral infections. The infections are also or viral infections. The infections are also caused by the parasites of the intestine caused by the parasites of the intestine like tape worm, round worm, thread worm, like tape worm, round worm, thread worm, hook worm, pin worm etc.hook worm, pin worm etc.

CONSTIPATIONCONSTIPATION WHAT IS WHAT IS

CONSTIPATION?CONSTIPATION?Constipation, costiveness, or irregularity, is a condition of the digestive system where a person (or animal) experiences hard feces that are difficult to egest. It may be extremely painful, and in severe cases (fecal impaction) lead to symptoms of bowel obstruction

CAUSES AND TREATMENT:CAUSES AND TREATMENT:Causes of constipation may be dietary, hormonal, anatomical, a side effect of medications (e.g. some painkillers), or an illness or disorder. Treatments consist of changes in dietary and exercise habits, the use of laxatives, and other medical interventions depending on the underlying cause.

DIARRHOEADIARRHOEA WHAT IS DIARRHOEA-WHAT IS DIARRHOEA-Diarrhoea is loose, watery Diarrhoea is loose, watery

stools. Diarrhoea can cause dehydration, which stools. Diarrhoea can cause dehydration, which means the body lacks enough fluid to function means the body lacks enough fluid to function properly.properly.

CAUSE- CAUSE- Acute diarrhea is usually related to a Acute diarrhea is usually related to a bacterial, viral, or parasitic infection. Chronic diarrhea bacterial, viral, or parasitic infection. Chronic diarrhea is usually related to functional disorders such as is usually related to functional disorders such as irritable bowel syndrome or inflammatory bowel irritable bowel syndrome or inflammatory bowel disease disease

SYMPTOMS- SYMPTOMS- Diarrhea may be accompanied by Diarrhea may be accompanied by cramping, abdominal pain, bloating, nausea, or an cramping, abdominal pain, bloating, nausea, or an urgent need to use the bathroom. Depending on the urgent need to use the bathroom. Depending on the

cause, a person may have a fever or bloody stoolscause, a person may have a fever or bloody stools

JAUNDICEJAUNDICE

Jaundice, also known Jaundice, also known as icterus (attributive as icterus (attributive adjective: "icteric"), is adjective: "icteric"), is yellowish discoloration yellowish discoloration of the skin, comjuctiva of the skin, comjuctiva (a clear covering over (a clear covering over the sclera, or whites of the sclera, or whites of the eyes) and mucous the eyes) and mucous membranes caused by membranes caused by hyperbilirubinemiahyperbilirubinemia

INDIGESTIONINDIGESTION

WHAT IS INDIGESTION?WHAT IS INDIGESTION?

Indigestion is a condition that is frequently caused by eating too fast, especially by eating high-fat foods quickly.

CAUSES:CAUSES: Excessive acid accumulation in the Excessive acid accumulation in the

stomach.stomach. Over consumption of alcoholOver consumption of alcohol OvereatingOvereating

SYMPTOMSSYMPTOMS Pain or burning feeling in upper part Pain or burning feeling in upper part

of the stomachof the stomach HeartburnHeartburn NauseaNausea

MANAGEMENT:MANAGEMENT: Use of antacidsUse of antacids Digestive enzymes capsuleDigestive enzymes capsule Activity modificationActivity modification RestRest

PREPARED BY-PREPARED BY-

SHAMIM AKHTAR , M.N. SHAMIM AKHTAR , M.N. RENUKARENUKA

XI-AXI-A