Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GI Exam 1 > GI secretions > Flashcards

GI secretions Flashcards

1
Q

In the duct of salivary glands, what are the main things secreted (2) and the main things reabsorbed (2)?

A

Secreted: bicarb, potassium
Absorbed: sodium, chloride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Salivary secretion is always secreted isotonic in the acinus but then as it proceeds thru the ducts and out into the GI tract it is hypotonic. How does the flow rate of saliva affect tonicity?

A

Faster flow rates lead to less hypotonic saliva and slower flow rates lead to more hypotonic saliva. This is because the reabsorption and secretion is given more time during slow flow rate and the Na/K pump reabsorbs 3 sodium and secretes 2 potassium leading to less osmolarity in saliva overall.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name the two major chemical mediators that increase saliva secretion.

A
  1. VIP (major)
  2. ACh
    parasympathetics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does bradykinin lead to increased salivary production?

A

Vasodilation of blood vessels allows more fluid to surround the acinar cells that can be used for salivary secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the major function of the bicarb secreted in saliva?

A

Neutralize acid that may reflux from the stomach in the distal esophagus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Name the 3 gastric endocrine cells and what each secretes.

A
  1. G-cells: gastrin
  2. Enterochromaffin-Like (ECL) cells: histamine
  3. D-cells: somatostatin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What do gastric parietal cells secrete?

A
  1. HCl

2. Intrinsic Factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the Alkaline Tide?

A

Carbon dioxide diffuses into gastric parietal cells where carbonic anhydrase combines it with water to form carbonic acid. The acid dissociates to form a proton and bicarbonate. The bicarbonate is transported thru a bicarb/Cl- antiport back into the blood resulting in alkaline blood stream by the stomach.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do protons in the parietal cells exit into the stomach lumen?

A

Thru a H+/K+ antiport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 3 activators of acid secretion?

A
  1. Histamine (major)
  2. Gastrin
  3. ACh
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name two major inhibitors of acid production.

A
  1. Somatostatin

2. Prostaglandins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Name 5 hormones that signal D cells to secrete somatostatin.

A
  1. VIP
  2. Secretin
  3. Low pH
  4. GIP
  5. Glucagon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does acid damage the mucosa layer?

A

The protons enter the mucosal layer and stimulate mast cells with release immune mediators that signal the immune system to release damaging inflammatory mediators.

It also activates pepsinogen which breaks down proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a general mechanism that leads to stress ulcers?

A

Trauma, burns, ventilators lead to an increase in sympathetic activity. This constricts blood vessels around the GI tract. The mucosa in the stomach and duodenum need the blood supply for nutrients so that they can produce the protective mucous. Without the blood supply the mucous is not produced.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What supplies the bicarb to neutralize acid that enters the duodenum?

A

Pancreatic exocrine duct cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Zymogen released by the pancreas that activates all the other enzymes released by the pancreas.

A

Trypsinogen: activated by enterokinase located on the duodenal lumen wall
(if a blockage occurs in the exocrine ducts, trypsinogen can “self-activate” and lead to pancreatitis)

17
Q

Name the 2 major stimulators of zymogen secretion from pancreatic acinar cells.

A
  1. CCK (from duodenal I-cells)

2. ACh

18
Q

How do cystic fibrosis patients get pancreatitis?

A

Lack of CFTR channel prevents water from entering the lumen of the pancreatic ducts. The zymogens cannot flow into the duodenum and remain in the pancreas where they are activated.

19
Q

Name the 2 major stimulators of bicarb and potassium secretion from pancreatic ductal cells.

A
  1. Secretin (from S-cells, stimulated by acid, fats, proteins)
  2. VIP
20
Q

What is the regulator of bile production in the liver?

A

The amount of bile that is recycled in the enterohepatic circulation.

21
Q

Regulator that relaxes the sphincter of oddi and contracts gallbladder smooth muscle.

A

CCK

22
Q

Regulator that increases liver ductal secretion of bicarb to increase flow of bile salts into the biliary system.

A

Secretin

23
Q

How does bile enter the portal circulation from the ileum?

A

Thru a Na+/bile symporter

24
Q

Name 4 causes of gallstones.

A
  1. Gallbladder concentrates bile to 5x that of circulation. stones can be caused by reabsorbing too much water
  2. Reabsorbing too much bile salts
  3. Too much cholesterol
  4. Inflamed epithelium
25
Q

What neutralizes acid in the early duodenum?

A

Brunner’s glands which secrete mucous.

Bicarb from the pancreas and duodenal mucosa

26
Q

Name the 2 major stimulators of bicarb and potassium secretion from intestinal ductal cells.

A
  1. Secretin
  2. VIP
    (same as pancreatic ductal cells)
27
Q

Main secretion in the colon.

A

Potassium. Chronic diarrhea leads to hypokalemia

GI Exam 1 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions