Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physiology III > Lecture 30: Intestinal Transport of Electrolytes and Water > Flashcards

Lecture 30: Intestinal Transport of Electrolytes and Water Flashcards

1
Q

What are the 3 ways for water intake

A

Food, drink and metabolic water

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

What are the 5 ways to lose water

A

Skin, lungs, GI tract, kidneys and milk

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

What are the enterosystemic sources of fluid

A
  1. Oral intake
  2. Saliva
  3. Secretion form stomach, pancreas, liver, SI and LI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is insensible evaporation

A

Humidification of breathing

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

What is a normal fluid balance important for intestinal function

A

Creates an appropriate environment for digestion, fermentation, and absorption, stabilizes pH

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

What % of fluid is recovered in small and large intestine

A

98%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

In dogs and cats, what % of fluid is reabsorbed in small intestine

A

80%

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

In dogs and cats, what % of fluid is reabsorbed in large intestine

A

18%

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

Colonic fluid provides __

A

Reserve capacity

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

What portion of the LI has a high absorptive capacity

A

Colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

___is the site for control of enterosystemic fluid balance

A

Epithelium

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

At what area of the epithelium does secretion occur

A

Crypts of small and large intestine

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

At what area of the epithelium does absorption occur

A

Villi of small intestine

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

What activates secretory mechanisms

A

Meals/food

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

What compensatory mechanism occur in order to increase uptake or excrete solutes and water

A

Expression of intestinal/epithelial transporters which can match the need

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

What does the SI absorbed

A

Water, Na+, Cl-, K+

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

What does the SI secrete

A

HCO3-

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

What does the LI absorb

A

Water, Na+, Cl-

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

What does LI secrete

A

K+ and HCO3-

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

T or F: SI fluid absorption is isomolar

A

True

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

What causes an increase in water absorption in GI

A

Increase in luminal osmotic pressure resulting from an influx and digestion of food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What ion facilitates the absorption of Na+ and water in the GI

23
Q

__stimulation of the luminal surface triggers chloride secretion

A

Mechanical

24
Q

___plexus is involved in mediating the secretory response

A

Submucosal

25
Stroking of the luminal surface releases ___ from unknown sources and causes __ secretion
Prostaglandins, and Cl-
26
Stroking of the musical surface also causes ___ release from enterochromaffin cells
Serotonin
27
Serotonin activates 5-HT1P/5-HT4 receptors containing substance P, ACh, glutamate. Release of these neurotransmitters activates release of ACh or VIP and cause __secretion
Cl-
28
What receptor is Cl- secretion linked to
CFTR
29
What are the two mechanisms in which CFTR can be activated
1. Food binds receptors on apical membrane 2. Receptors on basolateral membrane activated and increase Ca2+ and cAMP and pKA which phosphorylates CFTR channel and transport Cl- into intestinal lumen
30
What are some agonists that can activate basolateral K channel and CFTR
ACh, histamine, bile acids
31
What channel on basolateral membrane supplies cell with Cl-
NKCC1
32
How does V. Cholera toxin activate CFTR channel
1. Toxin is released from bacteria 2. Toxin activates G-protein and then AC 3. CAMP increase and opens CFTR
33
How does V. Cholera cause diarrhea
When it activates CFTR channel and increase Cl- secretion into lumen it draws Na+ and water into lumen resulting in diarrhea
34
How does the chyme remain isosmotic throughout passage throughout SI and LI
Balance between water secretion and absorption
35
How does water cross epithelium in GI
Passes through tight junctions
36
What two secondary active co-transporters are most important for fluid reuptake in GI
1. Na+/glucose 2. Na+/Amino acids
37
How does oral rehydration therapy work
Utilizes SGLT1 channel to drive H20 reabsorption
38
How do you activate the colonic reserve capacity
Stimulate ENaC channel in CD
39
How is ENaC activated
1. Aldosterone activates Na/K pump 2. Triggers insertion of preformed Na+ channels 3. Triggers expression of new channel proteins
40
__ is responsible for Na+ uptake from luminal fluid
ENaC
41
___ alters the rate of insertion, degradation and recycling of ENaC
Aldosterone
42
Describe the pathway of activating the RAAS system
1. Decrease pressure/blood loss 2. Angiotensinogen 3. AI 4. AII 5. Aldosterone 6. Kidney reabsorb Na+ and water 7. Colon reabsorbs Na+ and Cl- via ENac
43
How does amiloride work
Potassium sparing diuretic that blocks ENaC and inhibits Na+ absorption in distal colon of GI, promotes loss of Na+ and H20
44
Describe K+ absorption in the small intestine
Passive via solvent drag, uptake H20 take K+ with it
45
Describe K+ absorption in distal colon
Active K+ absorption based on pH. Increase H+ ions, decrease pH causes active K+ uptake
46
What transporter recovers K+ in the distal colon if diet K+ is low
H/K+ ATPase
47
What happens to K+ absorption if water is lost (ex: diarrhea)
Can’t build up gradient and can lead to hypokalemia
48
what are the 2 mechanisms Cl- is absorbed in GI tract
1. Voltage gated dependent- passive paracellular and transcellular Cl- absorption drive by SGLT or ENac 2. Electroneutral Cl-HCO3- exchanger
49
Where is the Cl-HCO3- present in GI
Epithelial cells of villi and surface cells of ileum and proximal colon
50
Why is the Cl/HCO3- exchanger important for hindgut
Net movement of bicarbonate into the gut elevates the pH which is important for hindgut fermentation Tightly linked to acid base homeostasis
51
What triggers Na+/H+ exchanger
High luminal pH
52
What causes the luminal pH to be high and then trigger Na/H+ exchanger
Secretin is stimulated in the SI from the arrival of acidic material from stomach, increase secretion of HCO3- in ductal cells, increasing pH and triggering Na/H+ exchanger
53
Describe the electroneutral absorption of Na and Cl-
The Cl-/HCO3- exchanger stimulated ton combat low pH from stomach acid by releasing bicarb into lumen and in response Na/H exchanger is activated to combat high luminal pH
54
Why can diarrhea occur after surgical resection of large part of the ileum
1. Bile salts and acids spill over into the colon because transporters in ileum reduced and maxed out. 2. Bile acid build up stimulate CFTR in colon which stimulates motility 3. Isosmotic absorption of h20 is compromised and decreased NACl- is decreased so resulting in diarrhea

Physiology III (34 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions