SGNA GI Anatomy and Physiology 2 — Questions and Answers
Question 1: Peristalsis in the GI tract is primarily controlled by which nervous system component?
- Enteric nervous system (Correct answer)
- Central nervous system only
- Sympathetic nervous system
- Somatic nervous system
Correct answer: Enteric nervous system
The enteric nervous system (ENS), often called the 'second brain,' autonomously regulates GI motility, secretion, and blood flow.
Question 2: Which hormone is primarily responsible for stimulating gastric acid secretion?
- Gastrin (Correct answer)
- Secretin
- Cholecystokinin
- Motilin
Correct answer: Gastrin
Gastrin, produced by G cells in the gastric antrum, stimulates parietal cells to secrete hydrochloric acid.
Question 3: Where does bile storage primarily occur between meals?
- Gallbladder (Correct answer)
- Common bile duct
- Liver sinusoids
- Cystic duct
Correct answer: Gallbladder
Between meals, bile produced by the liver is concentrated and stored in the gallbladder until released by cholecystokinin stimulation.
Question 4: The ileocecal valve serves what primary purpose?
- Prevents backflow of colonic contents into the ileum (Correct answer)
- Controls gastric emptying
- Regulates bile entry into the duodenum
- Separates the jejunum from the ileum
Correct answer: Prevents backflow of colonic contents into the ileum
The ileocecal valve acts as a one-way valve preventing colonic bacteria and contents from refluxing into the small intestine.
Question 5: Which layer of the GI wall contains the myenteric (Auerbach's) plexus?
- Muscularis propria (Correct answer)
- Submucosa
- Mucosa
- Serosa
Correct answer: Muscularis propria
Auerbach's (myenteric) plexus lies between the inner circular and outer longitudinal muscle layers of the muscularis propria, controlling motility.
Question 6: What type of epithelium lines the majority of the small intestine?
- Simple columnar epithelium (Correct answer)
- Stratified squamous epithelium
- Transitional epithelium
- Pseudostratified columnar epithelium
Correct answer: Simple columnar epithelium
Simple columnar epithelium with specialized enterocytes and goblet cells lines the small intestine, optimized for absorption and mucus secretion.
SGNA GI Anatomy and Physiology 2
Peristalsis in the GI tract is primarily controlled by which nervous system component?