GI 3 Flashcards

(50 cards)

1
Q

What is the total amount of daily secretions of mucous in the GI?

A

6.7 liters

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

mucous is secreted by what cells?

A

goblet cells

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

Which of the salivary glands only produce mucous?

A

buccal glands

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

Which of the salivary glands produce serous and mucous fluid? Why are they known as Extrinsic Glands?

A
  • parotid gland
  • submandibular gland
  • sublingual gland

they only inc/dec saliva secretion in response to Autonomic Stimulation or Chemoreceptors –> they produce 80% of the saliva

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

salivary constituents include a high level of these 3 things.

A
  • potassium
  • bicarbonate
  • amylase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 3 functions of saliva?

A
  • remove bacteria
  • destroy/opsonize bacteria via IgA
  • digest food particles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What can increase the secretion of saliva by 20x

A

sour taste

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

What are the 2 major secretions of parietal cells in the stomach?

A
  • intrinsic factor

- HCI

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

What does chief cells secrete?

A

pepsinogen

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

What are the 3 stimuli of HCL formation?

A
  • Ach
  • Gastrin
  • Histamine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Stomach cancer is associated with what infection?

A

H. pylori infection in the fundus

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

Intrinsic factor is important in the absorption of what vitamin?

A

Vitamin B12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What converts pepsinogen to pepsin?

A

presence of HCl

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

Where does the K+ come from for the H+/K+ antipoter?

A

saliva and leak channels

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

What is the major secretion of the pancreas?

A

sodium bicarbonate

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

bicarbonate is secreted by ductal cells in response to what?

A

secretin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

trypsinogen is converted into trypsin by what

A

enterokinase enzyme in SI

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does the pancreas secrete to break down protein?

A

trypsin

carboxypolypeptidase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does the pancreas secrete to break down carbs?

A

pancreatic amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the pancreas secrete to break down fats?

A

pancreatic lipase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what does pancreatic lipase do?

A

breakdown triglycerides into fatty acids and glycerol

22
Q

what is the major secretion of the liver?

23
Q

what is the main function of bile?

24
Q

Why don’t we see unconjugated bilirubin in the urine?

A

it is bound to albumin

25
What causes gallstones?
cholesterol will precipitate if its concentration exceeds the ability of the bile salts to emulsify
26
what is the function of the Brunner's glands?
secrete bicarbonate in small intestines
27
what is the function of the crypts of Lieberkuhn?
secretes mucous/electrolytes/water into the small intestine
28
what is the major and only secretion of the large intestines?
mucous
29
What are the major function of mucous in the GI tract?
- Protect against abrasions - Lubrication - Resistant to digestion - Buffers acids/bases
30
What are the 2 major stimulations of secretions?
``` Mechanical Stimuli from food Nervous stimulation (distention, chemicals, autonomic) ```
31
What stimulates G Cells to secrete Gastrin and what is the physiologic response?
Negatively charged proteins enter stomach --> buffers acids --> pH increases --> stimulates gastrin release --> parietal cells release HCl --> pH decreases
32
D Cells secrete somatostatin in response to what pH change in the stomach?
pH decreases (increased acidity) This inhibits gastrin --> decrease HCl secretion from parietal cells
33
How does the structure of the Oxyntic Tubular Gland impact pepsinogen function?
Tubular Glands are a "pit" --> Chief Cells are deep in pit --> secrete pepsinogen --> does not get activated until it moves UP the gland toward the lumen --> pH is low at the lumen --> acidity triggers pepsinogen conversion to pepsin --> prevents autodigestion of the stomach
34
What structures of the Parietal Cell allow us to use medications to decrease acid secretion?
H2 Receptor Antagonists (Ranitidine) | Proton Pump Inhibitors (Omeprazole)
35
Intrinsic Factor secreted from Parietal Cells helps absorption of Vitamin B12 in what way?
Intrinsic Factor binds to B12 and prevents it from being digested in the gut --> also allows it to be better absorbed in the Small Intestine
36
What triggers (2) Pepsinogen release from Chief Cells?
1. Parasympathetic stimulation | 2. Direct stimulation via chemoreceptors from stomach acid
37
Where in the stomach are Chief Cells located?
Body of Fundus
38
Where in the stomach are G Cells?
Antrum
39
What stimulates the pancreas to secrete bicarbonate?
Low pH chyme enters the duodenum --> S Cells --> secrete Secretin --> stimulates pancreas to release bicarbonate
40
Why does the pancreas not digest itself with the presence of trypsinogen?
Trypsinogen held under inhibition from Trypsin Inhibitor --> stops auto-activation
41
Trypsinogen gets converted to trypsin when and where?
Inhibited trypsin travels via the pancreatic duct to the duodenum --> encounters brush border enterokinases --> activate to trypsin
42
Pancreatic Amylase convers starch carbohydrates into di- and tri-saccharides. Name the 3 main disaccharides.
Maltose Sucrose Lactose
43
Where do the 3 disaccharides get converted to monosaccharides for absorption?
Brush border of small intestines
44
Name the components that make up the 3 Disaccharides: Maltose, Sucrose, Lactose
``` Maltose = glucose + glucose Sucrose = glucose + fructose Lactose = glucose + galactose ```
45
Explain the passage of bile from hepatocytes.
Hepatocytes --> Bile Canuliculi --> Terminal Bile Ducts --> Hepatic Duct --> Common Bile Duct --> Sphincter of Oddi (when open) --> Ampula of Vater ---> directly into Duodenum
46
What hormone triggers the gallbladder to contract, to release bile, and to relax the Sphincter of Oddi?
CCK
47
What triggers I cells to release CCK?
fatty acids entering the duodenum
48
Where are Brunner's Glands located?
In the Small Intestine between Pylorus and Ampulla of Vater
49
What causes the secretion of bicarb from Brunner's Glands?
Acidic (low) pH chyme entering the duodenum
50
Mucous secretion of the large intestine has what main purpose?
prevent abrasion of GI wall from solid fecal material