Questions and Answers

Describe the features of gas exchange surfaces in humans, limited to: large surface area, thin surface, good blood and air supply

State the function of the hepatic portal vein as the route taken to the liver by most of the molecules and ions absorbed from the ileum

Understand that water is absorbed from the lumen of the small intestine and the colon, but that most absorption of water happens in the small intestine

Explain the significance of villi and microvilli in increasing the internal surface area of the ileum

Describe the structure of a villus and the roles of capillaries and lacteals

Understand that assimilation is the uptake and use by cells of nutrients from the blood

Understand that absorption (by diffusion, osmosis and active transport) is the movement of nutrients from the intestines into cells lining the digestive system and then into the blood

State that the small intestine is the region where nutrients are absorbed

Describe peristalsis as waves of contractions of longitudinal and circular muscles which move food through the digestive system

Outline the role of bile in emulsifying fats to increase the surface area for the chemical digestion of fat to fatty acids and glycerol by lipase