2.2 GI Physiology: GI Hormones and Acid Secretion

Questions and Answers

What is the main component of gastric exocrine secretion responsible for protein digestion?

Pepsin

What is the primary function of amylase in the oral cavity?

Breaking down carbohydrates

Which of the following is a stimulant of acid secretion in the stomach?

Gastrin

What is the primary function of lingual lipase in the oral cavity?

Breaking down lipids Signup and view all the answers

What is the primary function of mucous in the oral cavity?

Lubrication Signup and view all the answers

What is the primary function of Parietal cells in the stomach?

Producing HCl Signup and view all the answers

Which cranial nerve is involved in the regulation of salivation?

CNs VII and IX Signup and view all the answers

Which of the following is NOT a stimulant of acid secretion in the stomach?

Motilin Signup and view all the answers

During the Cephalic Stage of Digestion, which nerve is excited to stimulate secretion and motility in the stomach, pancreas, and duodenum?

Vagus Nerve Signup and view all the answers

What is the primary function of Cholecystokinin (CCK) in the digestive system?

Gall Bladder Contraction Signup and view all the answers

Which hormone is responsible for stimulating gastric and intestinal motility?

Motilin Signup and view all the answers

What is the primary function of Secretin in the digestive system?

Pancreatic and Biliary Bicarbonate Release Signup and view all the answers

What is the role of Gastrin in the regulation of gastric acid secretion?

Stimulates gastric acid secretion Signup and view all the answers

Which hormones are responsible for stimulating the release of pancreatic enzymes and bicarbonate?

Cholecystokinin (CCK) and Secretin Signup and view all the answers

What is the role of Somatostatin in the regulation of gastric acid secretion?

Inhibits gastric acid secretion Signup and view all the answers

Which hormone is responsible for stimulating the release of insulin from the pancreas?

Gastric Inhibitory Peptide (GIP) Signup and view all the answers

What is the role of Vasoactive Intestinal Peptide (VIP) in the digestive system?

Relaxes sphincters and smooth muscle Signup and view all the answers

Which hormone is responsible for stimulating the release of histamine from the gastric mucosa?

Gastrin Signup and view all the answers

What is the primary function of the vagus nerve in the cephalic stage of digestion?

Stimulating the release of gastrin Signup and view all the answers

What is the primary function of cholecystokinin (CCK) in relation to the gallbladder?

Stimulating the release of bile into the duodenum Signup and view all the answers

What is the primary function of motilin in the gut?

Stimulating the contraction of smooth muscle in the gut Signup and view all the answers

What is the primary function of secretin in relation to pancreatic enzyme secretion?

Stimulating the release of bicarbonate-rich pancreatic juice Signup and view all the answers

Which of the following hormones is responsible for regulating gastric acid secretion?

Gastrin Signup and view all the answers

What is the primary function of CCK in relation to pancreatic enzyme secretion?

Stimulating the release of pancreatic enzymes Signup and view all the answers

What is the primary function of somatostatin in the regulation of gastric acid secretion?

Inhibiting the release of gastric acid Signup and view all the answers

Which of the following hormones is responsible for stimulating the release of bicarbonate-rich pancreatic juice?

Secretin Signup and view all the answers

What is the primary function of the pancreas in the digestive system?

Producing enzymes that facilitate protein digestion Signup and view all the answers

Study Notes

GI Physiology – Key GI Hormones

Vago-Vagal Reflex: stimulates the stomach, pancreas, and duodenum to prepare for digestion
Cephalic Stage/Phase of Digestion: chewing, tasting, and swallowing excites the Vagus, which then sends impulses to the stomach, pancreas, and duodenum to improve secretion and motility

Gastric Acid Secretion

Gastrin: produced by G-cells in the gastric antrum, stimulates gastric acid secretion
Histamine: produced by ECL-cells in the gastric mucosa, stimulates gastric acid secretion
Ach: stimulates gastric acid secretion through parasympathetic nerves
Gastric Inhibitory Peptide (GIP): inhibits gastric acid secretion
Somatostatin: inhibits gastric acid secretion and gastric gland mucosa repair

Exocrine Secretion

Salivary Glands: produce saliva containing amylase, lingual lipase, mucous, antibacterial agents, glycoproteins, and nerve and epidermal growth factors
Stomach: produces gastric exocrine secretion including HCl, pepsin, lipase, mucous, and gastric intrinsic factor

Hormones and their Effects

Gastrin: stimulates gastric acid secretion, gastric gland mucosa repair, and gall bladder contraction
CCK (Cholecystokinin): stimulates gall bladder contraction, pancreatic enzyme release, and pancreatic bicarbonate release
Secretin: stimulates pancreatic and biliary bicarbonate release, pepsin secretion, and repair of exocrine pancreas
GIP (Gastric Inhibitory Peptide): stimulates insulin release, inhibits gastric acid secretion
Motilin: stimulates gastric and intestinal motility

GI Tract Movement

Vagus Nerve: stimulates gastric and intestinal motility
Motilin: stimulates gastric and intestinal motility
Enkephalins: stimulate smooth muscle contraction and intestinal secretion

Integrated Systemic View

Gastric and intestinal phases of digestion are controlled by the Vagus and local reflexes
Hormones and nerves interact to regulate digestion and absorption

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Learn about key GI hormones, their functions, and their role in gastric acid secretion. Covers Vago-Vagal Reflex, Cephalic Stage, Gastrin, and Histamine.