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Preksha Dhyana :
important organ of the digestive tract. The second and third portions of the small intestine are called jejunum and ileum respectively. The major part of tood-digestion and absorption takes place here. Peristalsis, the slow automatic movement along the whole length of the tract, propels the contents continuously onwards.
Next to the small intestine comes the large intestine or bowel. It is much wider—6 to 8 cms. in diameter, and about 2 metres in length. First it passes upwards. It bends when it reaches the bottom of the liver and remains horizontal upto the spleen. Then it bends downwards : its last part is in the pelvic cavity and is called the rectum. Finally, it ends at the external opening, the anus. Its outside wall is puckered rather than tube-like. Its lining secretes mucus but no digestive enzymes.
Accessory Organs of the Digestive System Liver and Biliary System
The liver is the most important and an extraordinary organ which contributes to the process of digestion. It is reddish brown in colour and weighs about 1.5 to 2 kg. It is not only the largest but the most versatile single organ in the body. It lies in the upper part of the abdomen on the right side, beneath (and loosely attached to the diaphragm. The bile secreted by the liver goes to the gall-- bladder through bile-ducts, where it is stored and concentrated. Liver is the largest chemical factory in the body, and has at least five hundred known functions. Pancreas and the Islets of Langerhans
Pancreas is an oblong, rather flattened, boneless, fatless and fleshy gland about 15 to 18 cms. long and 4 cms. wide. It has a head, a body and and a tail; its head rests in the curve of the duodenum and its tail touches the spleen. It is a versatile organ, the second largest gland in the body (liver being the largest). It is connected to the duodenum through the pancreatic duct which extends throughout its length. 700 mls. of pancreatic juice containing several
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