Digestive Hormones and Enzymes

Enzymes in the ___________ require a low pH. A. Stomach B. Pancreas C. Mouth D. Small intestine

A. Stomach (Remember that low pH (1-7) means acidic!)

What breaks down small polypeptides/small peptides into amino acids?

Aminopeptidases, carboxypeptidase, and dipeptidase. (Brush Border Enzymes)

Which of the following enzymes can be found in the stomach? A. Trypsin B. Pepsin C. Lipase D. Maltase

B. Pepsin

Where is bile stored? A. Pancreas B. Liver C. Gallbladder D. Duodenum

C. Gallbladder

Which substance is responsible for making the pH of the small intestine slightly basic? A. Trypsin B. Salivary amylase C. Pancreatic juice D. Pancreatic amylase

C. Pancreatic (Remember that basic means a high pH (7-14)!)

A secretion produced by the _________________ contains digestive enzymes that act on every major component of food. A. Pancreas B. Duodenum C. Salivary Glands D. Gastric Glands

C. Salivary Glands

Starch is mainly digested in __________________. A. The mouth B. The stomach C. The small intestine D. Both a and c

C. Small intestine (tricky!)

Site of Production is duodenal mucosa. The stimulus for production is fatty chyme but also partially digested proteins. Target organ is the pancreas/liver, pancreas, gallbladder, hepatopancreatic sphincter (of Oddi). Potentiates secretin's actions, increases output of enzyme rich pancreatic juice. Stimulates organs to contract and expel stored bile. Relaxes to allow entry of bile and pancreatic juice in duodenum.

CCK (Cholecystokinin)

Most secretions involved in digestion are, at some point or another, sent through the: A. Liver B. Gallbladder C. Stomach D. Duodenum E. Esophagus

D. Duodenum (tricky!)

Unemulsified fats are broken down into monoglycerides and fatty acids, and glycerol and fatty acids by?

Emulsifying bile salts in liver and Pancreatic lipase (In order of occurrence).

Site of Production is duodenal mucosa. The stimulus for production is fatty and/or glucose containing chyme. Target organ is the stomach. Inhibits gastric gland secretion and gastric mobility during gastric phase.

GIP (Gastric inhibitory peptide)

Site of Production is stomach mucosa. The stimulus for production is food in the stomach; acetylcholine released by nerve fibers. Target Organ is the stomach, small intestine, Ileocecal valve, and large intestine. Causes gastric glands to increase secretory activity; most pronounced effect is on HCI secretion. Stimulates gastric emptying, stimulates contraction of intestinal muscles. Relaxes ileocecal valves and stimulates mass movement.

Gastrin

All enzymes are transported sooner or later to the liver via what vein?

Hepatic portal vein

Site of Production is stomach mucosa. The stimulus for production is food in the stomach. Target organ is the stomach. Activates parietal cells o release HCI.

Histamine

Site of Production is duodenal mucosa. The stimulus for production is acidic and partially digested food in the duodenum. Target organ is the stomach. Stimulates gastric glands and mobility.

Intestinal Gastrin

What breaks down Lactose, Maltose, and Sucrose into Galactose, Glucose and Fructose?

Lactase, maltase, sucrase, dextrinase, and glucoamylase. (Brush Border Enzymes)

What breaks down oligosaccharides and disaccharides into Lactose, Maltose, and Sucrose?

Lactase, maltase, sucrase, dextrinase, and glucoamylase. (Brush Border Enzymes)

What breaks down large polypeptides into small polypeptides and small peptides?

Pancreatic Enzymes

Nucleic acids are broken down into Pentose sugars, N-containing bases, and phosphate ions by?

Pancreatic ribonuclease and deoxyribonuclease, and Nucleosidases and phosphatases (Brush Border Enzymes)(in order of occurrence).

What breaks down protein into large polypeptides?

Pepsin

What is the order of protein digestion?

Protein, large polypeptides, small polypeptides and small peptides, and amino acids (some dipeptides and tripeptides).

What enzymes breaks down starch and disaccharides into oligosaccharides and disaccharides?

Salivary and Pancreatic amylase

Site of Production is duodenal mucosa. The stimulus for production is acidic chyme (also partially digested proteins, fats, hypertonic or hypotonic fluids, or irritants in chyme). Target organ is the stomach, pancreas, and liver. Inhibits gastric gland secretion and gastric mobility during gastric phase of secretion. Increases output of pancreatic juice rich in bicarbonate ions; potentiates CCK's action. Increase bile output in Liver.

Secretin

Site of Production is stomach mucosa. The stimulus for production is food in the stomach. Target organ is the stomach. Causes contraction of stomach muscles.

Serotonin

Where are Brush Border Enzymes found?

Small Intestines

Site of Production is stomach and duodenal mucosa. The stimulus for production is food in the stomach, and stimulation by sympathetic nerve fibers. Target organ is the stomach, pancreas, small intestine and the gallbladder. Inhibits gastric secretions of all products; inhibits gastric mobility and emptying. Inhibits secretion. Inhibits GI blood flow; inhibits intestinal absorption. Inhibits contraction and bile release.

Somatostatin

True or False? Amylase hydrolyses oligosaccharides and disaccharides into monosaccharides.

True

Lipid subunits?

Trypsin and chymotrypsin.

What are the Pancreatic Enzymes?

Trypsin, chymotrypsin, and carboxypeptidase.

Site of Production is duodenal mucosa. The stimulus for production is chyme containing partially digested foods. Target organ is the stomach and duodenum. Stimulates buffer secretion; dilates intestinal capillaries. Inhibits HCI production, relaxes intestinal smooth muscles.

VIP (Vasoactive intestinal peptide)