explain these terms Peristalsis Villi Composition of feces P

explain these terms

Peristalsis

Villi

Composition of feces

Solution

Villi: These are small fingure like projections present in small intestine. They are meant for increasing the surface area for absorption of digested food material.Villi consists of blood capillaries,lacteals. The fats absorbed from digested food are transported to lacteals in form of chylomicrons, whereas all other nutrients like amino acids and sugars from inetstine are transported to blood capillary.Each villus further has smalll microprojections called mirovilli to further increase the surface area for food absorption.

Composition of Feces:Feces consists of 75% of water by wieght and 25% of solid undigested matter( includes:undigested fibre, solidifed digestive juices, gut bacteria, fat etc). These are stored in rectum where furtehr water absorption continues from fecal matter. The color of feces is brown due to presence of urobilin and stercobilin which are metabolic products of bilirubin released from liver to assist fat digestion.

Peristalsis: These are rhythmic contractions and expansions in alimenatry canal that help to push the food forward into the alimentary canal (especially oesophagus and inetstine) for digestion. This is done with the help of longitudnal and circular smooth muscles present in the alimentay canal.

The similar movement in earthworm hydrostatic skeleton also helps in locomotion in earthworm.