Digestive System 2- Unit 4

Question 1

Bolus

Answer 1

Partially digested food

Question 2

How does the muscularis externa of esophagus change as it nears stomach?

Answer 2

Transitions from skeletal muscle to smooth muscle

Question 3

Upper esophageal sphinctor

Answer 3

Pharyngeal constrictors

Question 4

Gastroesophageal sphincter location

Answer 4

Top of stomach, below diaphragm (pierces diaphragm)

Question 5

GERD, Barrett’s esophagus, Cancer

Answer 5

GERD = chronic acid reflux, which damages esophagus lining, leading to callouses (Barrett’s), higher chance of esophageal cancer

Question 6

Gastroesophageal vs Pyloric sphincters

Answer 6

Pyloric is better

Question 7

Gastric rugae

Answer 7

Let stomach distend

Question 8

Extra smooth muscle layer in stomach’s muscularis externa/tunica muscularis

Answer 8

Inner oblique, deep to circular and longitudinal layers

Question 9

Intrinsic Factor

Answer 9

Made in gastric gland by chief/parietal cells, affects B12 levels

Question 10

Relationship between gastric gland cells

Answer 10

Mucous cells- make mucin
Parietal cells- make HCl, int. fac.
Chief cells- make pepsinogen
ECL- histamine 2 (autocrine)
G-cells- gastrin (autocrine)

Food, hormones, nervous system triggers G-Cells to make Gastrin. Gastrin activates Chief cells (found between mucous and parietal) and ECL cells. Chief cells make Pepsinogen, ECL makes make Histamine 2, which triggers Parietal cells to make int. fac. and HCl, which turns Pepsinogen into Pepsin.

Question 11

Peptic ulcer

Answer 11

Infection from helicobacter pylori, causing gastritis. (Barry Marshall)

Question 12

HCl functions

Answer 12

Protection from bacteria
Activates pepsin
Denatures proteins

Question 13

What does pepsin digest?

Answer 13

Denatured proteins

Question 14

Stomach absorbes

Answer 14

Water, simple sugars, fatty acids, alcohol, aspirin