Question

Describe the human digestive system? ​

Answer 1

HUMAN DIGESTIVE SYSTEM

The digestive system or the ailmentary canal starts in the buccal cavity and terminates in the anus. It is 8-10cm in length.

•Parts of the digestive system:

Buccal cavity: Mouth,tongue and teeth

Oesophagus

Stomach

Pancreas

Small Intestine

Anus

•Functions:

Buccal cavity:

The food here is chewed and partially digested(by the action of salivary amylase on starch and reducing it to maltose,a type of sugar).Teeth masticate the food,for easy swallowing of food. The food is called chyle

Oesophagus:

It is a long tubular structure which guides the food to the stomach. The muscles contract to pass on the food. This muscular movement is called peristalsis.

Stomach:

Here the food is acted upon by the digestive enzymes present in gastric juice. Pepsin reduces proteins to peptones.

There are three types of cells on the gastric glands:

1)Parietal cells:HCl

2) Zymogen Cells:Pepsin

3)Mucous cells:Mucus

Mucus protects the inner lining of gastric walls from corroding due to HCl

HCl activates Pepsin which is otherwise in it's inactive form

The food leaving stomach is called chyme(acidic in nature) and is regulated by pylorus sphincter.

Pancreas:

It produces insulin and glucagon which reduce glucose and provide energy for body activities.

Liver:

It produces the bile(alkaline in nature) which neutralises the acidic food coming from stomach.

Small intestine:

It has three parts: duodenum,jejunum and ileum. It is 6m in length. The partially digested proteins are digested by Trypsin and fats by the lipase. Digestion is completed over here.

Anus:

The undigested food is excreted from the body. This is regulated by anal sphincter