Human intestine : functions and diseases

Human intestine:-

Intestine is the part of digestive tract or alimentary tract, extends from stomach to anus. For anatomical study purpose, intestine is divided into large intestine and small intestine.

The part of intestine joins with stomach is small intestine and the large intestine joins small intestine. Small intestine measures about 6 meters length and is coiled in the abdominal cavity. The small intestine is further is further divided into three sections, Duodenum, Jejunum, and Ileum. Secretin is the hormone secreted by the lining of small intestine. Secretin stimulates the pancreas to produce other digestive enzymes. Small intestine secretes major enzymes and helps in digestion of food materials, and also acts as a passage for food.

Human large intestine measures nearly 1.5 meters in length. The large intestine is further divided into six parts, Cecum,  Transverse colon, Descending colon, Sigmoid colon, and Rectum. Large intestine is not coiled like small intestine.

The human intestine has a specialized glandular epithelium which secretes mucus and helps in digestion.

Functions:-

The functions of large intestine and large intestine are not same. Small intestine plays a major role in the digestion of food, by secreting digestive juices and small intestine is the place where digested food is absorbed. Digestion of carbohydrates, fats, and protein takes place in small intestine. Small intestine absorbs all the essential nutrients and are transmitted to blood stream.

Duodenum : First part of small intestine receives the food associated with acid and bile is also added from the gallbladder. Pancreatic juice is also delivered to duodenum and mixed with the food. Mixed food with mucus, bile and digestive enzymes from pancreas is digested in the small intestine and nutrients are absorbed.

Food in the intestine is passed by rhythmic contractions and relaxation is called Peristalsis.

Jejunum measures 1-2 meters and ilium measures 4-5 meters. Jejunum is the mid part of small intestine, is coiled and helps in digesting food and passage of food. Ilium is the end part and is joined with large intestine.

Large intestine absorbs the water and electrolytes in the digested food and excretes the solid waste of digested food. Large intestine forms the fecal matter and stores it in the end part of intestine. Microbial fermentation also occur in the large intestine.

Both small and large intestine digests food, absorbs nutrients, and helps in the elimination of food from the body.

Common diseases of intestines:-

* Cancer of intestine,
* infection of intestine by bacteria,
* injury to intestines,
* Coeliac diseases,
* Gastroenteritis,
* Ileitis, etc

Constipation, malabsorption syndrome, bowel irritation are considered as intestinal disorders.