Anatomy and Physiology Answer Key

Mixing also helps to expose the food in anatomy and

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: membrane of the epithelial cells. (b) Chylomicrons: These aggregations of fats are coated with protein in such a way that the fat remains in suspension during transport. 2. It is important that nutrient-rich blood from the gut is taken directly to the liver so that the nutrients can be removed and processed most rapidly and efficiently. Nutrient-rich blood has a high osmotic potential and therefore also represents a potential threat to homeostasis. Rapid removal of nutrients from the blood is desirable in terms of maintaining homeostasis. Site: Pancreas Enzymes: trypsin/chymotrypsin Purpose: Digestion of proteins to polypeptides. Site: Pancreas Enzyme: pancreatic lipase Purpose: Digestion of fats to fatty acids and glycerol. Site: Pancreas Enzymes: peptidases Purpose: Digestion of polypeptides to amino acids. The Control of Digestion (page 185) 1. (a) Food in the mouth causes a reflex stimulation of salivary glands and stomach (parasympathetic stimulation via the vagus). The effect is a marked increase in salivary and gastric secretion. (b) Presence of fat and acid in the small intestine stimulates release of cholecystokinin and secretin from the intestinal mucosa. These hormones inhibit gastric motility and stimulate the secretions of the pancreas, the production and release of bile, and the secretions of the intestinal glands. (c) Stretching of the stomach stimulates the reflex secretion of the hormone gastrin from the gastric mucosa. Gastrin acts back on the stomach to increase gastric secretion and motility. 2. The vagus nerve provides the parasympathetic innervation of the gut, stimulating salivary, gastric, and pancreatic secretion. Anatomy and Physiology Site: Intestinal mucosa Enzymes: peptidases. Purpose: Digestion of polypeptides to amino acids. Site: Intestinal mucosa Enzymes: maltase, lactase, sucrase Purpose: Digestion of carbohydrates (maltose, lactose, sucrose respectively) into their constituent parts. 4. (a) The enzymes involved in digestion in different region...
View Full Document

Ask a homework question - tutors are online