DIGESTIVE SYSTEM
The process of converting food into energy giving susbstances is carried out by this system.
1. Buccal Cavity
In the mouth salivary glands secrete saliva which contains the enzyme ptyalin.
Also contains Lysozyme which kills bacteria
Teeth: They are produced in two sets temporary and permanent. The teeth are of four types: Incisors, Canines, Premolars and Molars Structure of a Tooth:
It is covered by a shining material called Enamel.
Enamel is the hardest substance in the human body. Dental Formula:
2123/2123. This means that there are 2 incisors, 1 canine, 2 premolars and 3 molars in half of the upper jaw and exactly the same arrangement in half of the lower jaw. i.e. 32
The premolars and the molars are called the grinding teeth. The last molars are called the wisdom teeth.
Linked with pharyns.
Pharynx
Trachea opens into pharynx through an aperture called Glottis. It also receives the opening of the Eustachian tubes from the middle ear through an aperture called Gullet.
Oesophagus
25 cm long tube.
Leads to stomach
Stomach
In stomach, the food is called chime.
Has 3 parts: Fundus, Cardiac and Pyloric
It is a warehouse, where food can be stored to await the main process of digestion.
Gastric juices produced in the stomach help in digestion of food. Also contains HCl which kills bacteria and provides acidic medium.
Small intestine(Duodenum + Jejenum + Ileum)
Here the food from the stomach is mixed with bile (from liver) and pancreatic juice (from pancreas) and moves forward by peristaltic movement.
Duodenum receives the bile-pancreatic duct formed by the union of bile duct and pancreatic duct. Bot jejunum and ileum have numerous fingurelike projections called the villi.
Bile doesn’t take direct part in digestion of fat, it just makes the food alkaline.
Large Intestine (Caecum+colon + Rectum)
It receives undigested material from the small intestine and absorbs water.
Cellulose digestion takes place in it.
Vermiform appendix is a part of caecum, which produces antibodies.
TONGUE
Saliva, secreted by the salivary glands, is mixed with the chewed food by the tongue.
Tongue also contains taste buds due to which we sense bitter, sour, salty or sweet taste.
The process of converting food into energy giving susbstances is carried out by this system.
1. Buccal Cavity
In the mouth salivary glands secrete saliva which contains the enzyme ptyalin.
Also contains Lysozyme which kills bacteria
Teeth: They are produced in two sets temporary and permanent. The teeth are of four types: Incisors, Canines, Premolars and Molars Structure of a Tooth:
It is covered by a shining material called Enamel.
Enamel is the hardest substance in the human body. Dental Formula:
2123/2123. This means that there are 2 incisors, 1 canine, 2 premolars and 3 molars in half of the upper jaw and exactly the same arrangement in half of the lower jaw. i.e. 32
The premolars and the molars are called the grinding teeth. The last molars are called the wisdom teeth.
Linked with pharyns.
Pharynx
Trachea opens into pharynx through an aperture called Glottis. It also receives the opening of the Eustachian tubes from the middle ear through an aperture called Gullet.
Oesophagus
25 cm long tube.
Leads to stomach
Stomach
In stomach, the food is called chime.
Has 3 parts: Fundus, Cardiac and Pyloric
It is a warehouse, where food can be stored to await the main process of digestion.
Gastric juices produced in the stomach help in digestion of food. Also contains HCl which kills bacteria and provides acidic medium.
Small intestine(Duodenum + Jejenum + Ileum)
Here the food from the stomach is mixed with bile (from liver) and pancreatic juice (from pancreas) and moves forward by peristaltic movement.
Duodenum receives the bile-pancreatic duct formed by the union of bile duct and pancreatic duct. Bot jejunum and ileum have numerous fingurelike projections called the villi.
Bile doesn’t take direct part in digestion of fat, it just makes the food alkaline.
Large Intestine (Caecum+colon + Rectum)
It receives undigested material from the small intestine and absorbs water.
Cellulose digestion takes place in it.
Vermiform appendix is a part of caecum, which produces antibodies.
TONGUE
Saliva, secreted by the salivary glands, is mixed with the chewed food by the tongue.
Tongue also contains taste buds due to which we sense bitter, sour, salty or sweet taste.
இடுகைகள்
