Gastric Secretions Flashcards Preview

Medical Physiology > Gastric Secretions > Flashcards

Flashcards in Gastric Secretions Deck (17)
Loading flashcards...
1
Q

What is normal GIT secretions?

A

6-8 L/Day

2
Q

What is the role of Parietal Cells of the stomach?

A
  • Secrete HCl: Activates Pepsinogen and kills bacteria

- Secrete intrinsic factors: Comnpldes with Vit B12 (Cobalamine) for reabsorption

3
Q

What is the role of enterochromaffin cells of the Stomach?

A
  • Secrete Histamine: Stimulates Gastric Acid secretion
4
Q

What is the role of Chief cells of the stomach?

A

Release Pepsinogen: Cleaved and digests proteins

Release Gastric Lipase: Breaks down Fat

5
Q

What is the role of D Cells of the stomach?

A

Release Somatostatin: Inhibits Gastric Acid secretions

6
Q

What is the role of G Cells in the stomach?

A

Release Gastrin: Stimulates Gastric Acid secretions

7
Q

What are the mechanisms for HCl secretion?

A

ECL Cells —> Histamine —> Parietal H2 receptor —> H+ K+ ATPase

Vagal stimulation —> Ach —> M3 receptor —> H+ K+ ATPase

G Cells —> Gastrin —> CCK receptor —> H+ K+ ATPase

8
Q

How is Chlorine transported into the stomach?

A

Basolateral HCO3-\ Cl- transporter

CL= Channel on apical side

9
Q

How does Somatostatin inhibit gastric H+ secretion?

A
  1. Direct: Activating though GI protein thus inhibiting Adenylyl cyclase And CAMP
  2. Indirect: Inhibits Release of histamine and Gastrin
10
Q

How do prostaglandins affect Gastric H+?

A
  • Inhibits H+secretions b activating Gi protein
11
Q

How can NSAIDS promote peptic ulcer disease?

A

NSAIDS decrease prostaglandins which decrease H+ Secretions

INC H+ —> INC Ulcers

12
Q

How can gastric disease lead to macrolytic anemia?

A

Parietal cells deserted IF —> B12 reabsorption—> Deficiency —> MAcrolytic anemia

13
Q

Describe the D-Xylose Absorption test

A
  • Differentiate Small Noel vs pancreas malabsorption
  • If >5 gm than bowl is fine; pancreatic problems
  • If <5 gm then problem is in SI (Like celiac disease)
14
Q

What is treatment used for NSAID induced stomach ulcers?

A

Misprostol —> PGE2 analog

15
Q

Differentiate Gastric vs Duodenal ulcers

A

Gastric: Gain pain with eating

Duodenal: Lose pain when eating

16
Q

Describe Zollinger-Ellison syndrome

A

Gastrinoma:

  • Increase in Gastrin
  • Acid and pepsin overloads and results in duodenal ulcers
17
Q

What allows H. Pylori to thrive in the stomach? What is the fastest way to direct for H. Pylori?

A
  • Flagella allow it to move into deep Mucous layer
  • Urease allows mucous layer to be neutral (Urea + H20 —> NH3+ CO2)
  • Urease test (Urea breath Test) detects CO2 levels after Urea intake which indicates urease activity