In the large intestine the absorption of water continues until semisolid
consistency of faeces is achieved. Mineral salts, vitamins and some drugs are
also absorbed into the blood capillaries from the large intestine. The large
intestine is heavily colonized by certain types of bacteria which synthesize
vitamin K and Folic acid. Unabsorbed carbohydrate undergoes bacterial
fermentation and produces gas. These gases pass out of the bowel as flatus. The
large intestine exhibits mass movements.
Movements of the Gastro Intestinal Tract
the process by which the masticated food is
transported across the pharynx and reaches the stomach. Due to contractile
movements of the stomach, the food is well mixed up with gastric juice. After
being in the stomach for 3 or 4 hours the pyloric sphincter opens pushing the
food into the duodenum.
The small intestine shows three important types of movements, they are -
1. Pendular Movement
These movements are induced by contraction of the circular and
longitudinal muscles of the intestine. This movement contributes to the
thorough mixing of chyme with the digestive juice.
2. Segmenting Movement
This movement occurs by the contraction of the circular muscles which
produces transverse folds, dividing the intestine into short segments.
3. Peristaltic Movement
It is the wavelike contraction of the alimentary canal which propels the
food through the gastro intestinal tract.