Digestion notes

The wall of stomach undergoes periodic movement as well as contraction producing churning movement called peristalsis, which results in breakdown of complex food into simpler form.

Bile is alkaline and neutralises the acid which was added to the food in the stomach. It is carried out by passive, active or facilitated transport mechanisms.

Before swallowing the tongue rolls the food into a soft ball and pushes it to the back of the mouth. Digestive enzymes act only on the surfaces of food particles; therefore, the rate of digestion is dependent on the total surface area exposed to the digestive secretions.

Moves material that has not been digested along. Gastric glands have three major types of cells namely — i mucus cells: The mucus and bicarbonates present in the gastric juice play an important role in lubrication and protection of the mucosal epithelium from excoriation by the highly concentrated hydrochloric acid.

The pancreatic juice contains inactive enzymes — trypsinogen, chymotrypsinogen, procarboxypeptidases. Gastric glands have three major types of cells namely — i mucus cells: The glands in the wall of the small intestine produce intestinal juice.

Biologically active molecules such as hormones as well as toxins are broken down or modified by enzymes associated with hepatic cells and excreted in bile. The lacteal takes away fats after absorption.

This layer is made up of connective tissue that contains blood vessels, nerves and lymphatics, vessels that carry lymph material. In addition the villi also have their own projections which are called microvilli. Elimination of undigested food as faeces. The structure of the villus is very specific.

Epithelium is only one cell layer thick and so food is quickly absorbed. In addition, grinding the food to a very fine particulate consistency prevents excoriation of the gastrointestinal tract and increases the ease with which food is emptied from the stomach into the small intestine, then into all succeeding segments of the gut.

Carbohydrate digestion is continued in the intestine by pancreatic amylase. The egestion of faeces to the outside through the anal opening defaecation is a voluntary process and is carried out by a mass peristaltic movement.

Through passive and active diffusion, the nutrients will be absorbed into the blood stream and carried through the circulatory system to the rest of the body. The structural and functional units of liver containing hepatic cells which are arranged in the form of cords.

This is the taking of food into the alimentary tract, i.

Function of the Digestive System

Canines are pointed and used for piercing and tearing. Somatostatin from D cells inhibit HCl secretion. The absorbed substances finally reach the tissues which utilise them for their activities. This mechanism is called the facilitated transport. The bolus is then swallowed through Oesophagus to the stomach.

Carbohydrate digestion is continued in the intestine by pancreatic amylase. The stomach stores the food for hours. Stomach Secretion of pepsinogen from chief cells in stomach lining and hydrochloric acid from parietal cells.

The bolus is then swallowed through Oesophagus to the stomach. The anal sphincters provide fine control of stool. The vast majority of lipase is secreted by the pancreas. About ml per day gets to the large intestine and less than about ml is excreted.

HCL provides optimum pH for pepsin. The stomach is an important part of the digestive system. Fatty acids and glycerol being insoluble, cannot be absorbed into the blood. Trypsinogen is activated by enterokinase secreted by duodenum into trypsin, which in turn activates the other 3 enzymes —chymo-trypsinogen becomes chymotrypisn, proaminopeptidase becomes aminopeptidase, and procarboxypeptidase becomes carboxypeptidase.

During the process ofdigestion, polysaccharides are broken down into smaller chains and finally into disaccharides and monosaccharides. Human Anatomy & Physiology: Digestive System; Ziser Lecture Notes, 1 The Digestive System We need food for cellular utilization:!nutrients as building blocks for synthesis!sugars, etc to break down for energy most food that we eat cannot be directly used by the.

NEET Biology Notes Digestion Digestion. Digestion is a process which involves breakdown of complex food substances by hydrolysis into smaller molecules that can be absorbed through the epithelium of the gastro-intestinal tract.

Human and other animals have holozoic nutrition, i.e. intake of. Human Digestive System This is a complex process.

Physiology of digestion

The breakdown of the nutrients requires the coordination of several enzymes secreted from specialized cells within the mouth, stomach, intestines, and liver. Digestion is the process of gradual break down of foods that we eat in a soluble form suitable for absorption.

For example, meat, even when cooked, is chemically too complex to be absorbed from the alimentary elonghornsales.com, it first digested before absorption.

Digestive System Notes 1. Essentials of Human Anatomy & PhysiologyThe Digestive System Anatomy & Physiology II Mr. Hildebrandt Mouth Anatomy: Digestion begins• Hard palate – forms the anterior roof• Soft palate – forms the posterior roof• Uvula – fleshy projection of the soft palate• Tongue – attached at hyoid and skull 6.

Nutrition and Digestion BIOLOGY Notes MODULE - 2 Forms and Functions of Plants and animals In this lesson you will study the various modes of nutrition, types of digestion, the process of digestion of food, and its absorption and assimilation in humans.

Digestion notes
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Digestion, notes for Human Physiology, Bio