P3: Outline the gross structure of all main body systems
Digestive system: This is made up of the gastrointestinal tract also called the digestive system and the liver, pancreas and gall bladder. The gastrointestinal tract is a series of hollow organ that joined in a long twisting tube from mouth to the anus; the hollow organs made up the GI tract are the mouth, oesophagus, stomach, small intestine, large intestine which includes the rectum and anus. Food enters the mouth and passes to the anus through the hollow organs of the GI tract the liver, pancreas and goal bladder are the solid organs of the digestive system. The digestive system helps the body digest food, this is important for breaking down food into nutrients which the body uses for energy growth and cell repair food and drink must be changed into smaller molecules from nutrients before the bloody absorbs them and carries them to the cells throughout the body, the body breaks down the nutrients from food and drink into carbohydrates, protein, fats and vitamins. Digestion works by moving food through the GI tract, digestion begins in the mouth with chewing and anus in the small intestine as food passes thought the GI tract it mixes with digestion juices, which causes the large molecules of food to break down into smaller molecules the body then absorbs these smaller molecules through the walls of the small intestines into the bloodstream which delivers them to the rest of the body. Waste products of digestion pass through the large intestine and out the body as a solid matter called stool/poo.
The Teeth: Our teeth equip us for destroying chunks of food by a gamut of mechanical actions ranging from gripping and puncturing to grinding and pulverizing. The teeth in front canines and incisors do most of the gripping, ripping, and tearing, while the premolars and molars at the back of the jaws do the grinding
The Tongue: The is a muscular organ located on the floor of the mouth, is an extremely mobile structure and is an important accessory organ in such motor functions as speech, chewing, and swallowing. In conjunction with the cheeks, it is able to guide and maintain food between the upper and lower teeth until mastication is complete.
: The , which passes food from the mouth to the stomach, is about 25 cm (10 inches) in length the width varies from 1.5 to 2 cm (about 1 inch). The esophagus lies behind the and and in front of the it passes through the before entering the stomach.
The Liver: Is the largest internal organ in the human body it is on the right side of the abdominal cavity just below the diaphragm the liver performs a number of functions including storage of iron and some vitamins, removal of drugs, alcohol and other toxins from the blood, production of the heat that keeps the body warm and production of the bile salts that break down fat in the small intestines.
The Intestines: Are part of the alimentary canal extending from the stomach to the anus the small intestines is a greyish purple colour 35mm and 6m to 7m long in an average adult the main function of the small intestine is dark red colour and 1.5m long it stores undigested food as faeces until it is passed out of the body through the anus.
The Pancreas: Produces some of the hormones that control glucose levels in the blood to secrete enzymes into the small intestine that help the body to break down and digest food
The Kidneys: Are located at the back of the abdominal cavity there is 1 at each side of the spine just below the level of the diaphragm they are bean shaped and weigh between 115g and 170g in the adults with the left kidney slightly larger than the right the kidney filter out and remove excess salt, water and waste products from the blood creating urine they keep the composition of the blood balanced, maintain correct levels of minerals, salt and fluids.
The Stomach: Function is to store food while some of the processes of digestion take place in the stomach chewed solids are further broken down and mixed with digestive juices to form a liquid. Digestive enzymes in the juices catalyse the breakdown of food