Importance Of Animal Physiology

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Animal Physiology As the meaning of word ’anatomy’ is the biological form of an animal, physiology means the biological function of an animal. Animal physiology differs in several ways from animal to animal, but all animals share some principal functions. Such functions are attaining nutrients, performing osmoregulation and excretion, and protecting themselves against pathogens. Animals manage these actions by exchanging with the environment. Exchanging is the action when substances in an aqueous solution move across the plasma membrane. Usually this aqueous solution is an interstitial fluid, such as blood. As the animal grows larger, it’s not convenient for them to be single celled as efficiency of exchange depends on the membrane to surface …show more content…
Ingestion and some enzyme activity takes place in the oral cavity. This is a part when digestion is mostly mechanical, but the food activates salivary glands which produce amylase containing saliva. Mucus protects the mouth and makes the food easier to swallow. Tongue helps the bolus, the lump of food, to form and pushes it into the pharynx. The bolus will then travel down through esophagus to the stomach with the help of peristalsis that happens all the way in the esophagus. In the stomach, gastric juice is secreted and mixed with the food to form chyme. Gastric juice consists of HCL and pepsin. HCL creates low pH in the stomach that denatures proteins thus peptide bonds get exposed and vulnerable to pepsin. Proteins are cut up into smaller polypeptides by pepsin. The gastric juice does not destroy the stomach cells because they are activated only when they reach the lumen. HCL composes of hydrogen and chloride ions that are secreted by parietal cells. Pepsin is released by chief cells in the inactive form, pepsinogen. It is the HCL that catalyzes the chain of events of making pepsin …show more content…
This is the site for hydrolysis of the macromolecules to occur. In the first 25 cm of the small intestine, called duodenum, the chyme merges with digestive enzymes and an alkaline secretion from the pancreas and bile from gallbladder. The alkaline secretion from pancreas contains a lot of bicarbonate. It neutralizes the stomach acids of chyme. The digestive enzymes of pancreas help to digest lipids, carbohydrates and proteins. Bile breaks down fats. It is produced in the liver but stored in the gallbladder. The epithelial cells of the duodenum produce some enzymes. Most digestion finishes in duodenum and the next steps are to mold the wastes into a form that can exit the body easily. The large intestine is the last part of the alimentary canal. Its parts are cecum, colon, rectum and anal canal. The cecum is inhabited by symbiotic bacteria that are able to break down cellulose. Cellulose is a material that animal alimentary canal couldn’t digest independently without symbionts. Colon reabsorbs the excess water using osmosis. This solidifies the structure of feces. Colon has a lot of symbiotic bacteria of which some even produce vitamins. The feces leave the body through rectum and exit from

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