Human Digestive system (HDS) – Digestion and Organs of digestive system презентация

Human Digestive system (HDS) – Digestion and Organs of digestive system

NUTRIENTS and DIGESTIVE SYSTEM The energy that food provides is necessary for the continuity of life on earth Food can be divided into six groups: - carbohydrates - lipids - proteins - vitamins - minerals - water

Digestion

Digestive system organs The digestive tract is comprised of the - mouth - pharynx - esophagus - stomach - small intestine - large intestine

Digestive system The major glands which secrete substances are - salivary glands - glands of the stomach - glands in the intestinal wall - pancreas - liver

MOUTH The structures found in the mouth are - the teeth - salivary glands - the tongue Function of teeth is to grind food into small particles and to mix it with digestive secretions

Tongue regions Sweet foods are tasted at the tip of the tongue Bitter foods are tasted at the rear Sour and salty foods are simultaneously tasted on both sides of the tongue

Pharynx The pharynx is a cavity located directly behind the mouth, in front of the esophagus and trachea

Esophagus (25 cm) The esophagus is a pipe It passes from the pharynx to the stomach A rhythmic contraction of the digestive tract is called peristalsis, pushes the food Peristalsis begins in the esophagus

Stomach The largest portion Cardiac sphincter, a valve through which food enters the stomach Pyloric sphincter - it regulates the movement of chyme (a soupy liquid) into the duodenum

Stomach The stomach is composed of three layers of smooth muscle They regulate the movement of stomach Stomach has a mucosal layer (слизистая оболочка) Mucosal layer has gastric glands

Stomach Gastric glands produce - hydrochloric acid (HCl) - pepsinogen (enzyme) into the gastric juice, where it is converted to pepsin by HCl acid

Small Intestine (6 m) It has 3 segments: - duodenum (25 cm) - jejunum - ileum Function of the jejunum is the absorption of nutrients into the blood, because this part of small intestine has villi

Large Intestine (1.5 to 2 meters in length) It has 3 segments: - caecum - colon - rectum The appendix, a projection of the caecum This organ may become inflamed causing severe pain In such cases, it must be surgically removed

Pancreas Mixed gland It’s secretions have basic characteristics – neutralizes acidic (HCl) condition which comes from stomach It opens into small intestine Hormones – glugacon and insulin

Liver The liver is the largest organ of the body and gland It contains the gall bladder Bile duct leading from the gall bladder transmits bile salts, which break down fats in the duodenum

Functions of the liver Formation and secretion of bile Regulation of blood sugar level Formation of fibrinogen and thrombogen, which are active during blood clotting Detoxification of substances (ex, alcohol is broken down in liver) Stores Fe, Cu ions and vitamins A, D, E and K