Brainscape's Knowledge GenomeTM

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


See full index

Gastrointestinal > 13. Gut Fluid Balance - secretion, absorption, malabsorption > Flashcards

13. Gut Fluid Balance - secretion, absorption, malabsorption Flashcards

1
Q

EPITHELIAL CELLS can … or … WATER and ELECTROLYTES

A

SECRETE or ABSORB

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

FLUID INPUT per day

A

9 L

  • Ingest 2L
  • Saliva 1.5L
  • Gastric secretions 2L
  • Pancreatic juices 1.5L
  • Bile 0.5 L
  • Intestinal secretions 1.5L
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

FLUID OUTPUT per day

A

9 L

  • Small intestine absorbs 8.5L
  • Colon absorbs 0.4L
  • Excrete 0.1L
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

ENERGY is SUPPLIED by … and … GRADIENTS

A

SODIUM (by sodium pump) and PROTON gradients

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

what is PARACELLULAR ROUTE

A

between cells, THROUGH LEAKY TIGHT JUNCTIONS

  • Nutrients eg Na+ and most H2O by osmosis

TRANSCELLULAR: Through cells using transporters

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

ABSORPTION at which part of INTESTINAL walls

A

VILLUS

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

SECRETION at the … in Intestinal walls

A

CRYPT

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

DIFFERENTIATING CELLS of intestine walls move up from

A

CRYPT
- STEM CELLS
- PROLIFERATING ZONE

Move up and mature

  • old cells shed at top of villus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what FACTORS AFFECT ABSORPTION and SECRETION

A
  • NUTRIENT INTAKE
  • GASTRIC MOTILITY
  • INTESSTINAL MOTILITY (increased = less time for absorption)
  • NUMBER and STATE of ENTEROCTES
  • BLOOD and LYMPH FLOWS (clearance rate)

Regulated by
- HORMONAL, PARACRINE, NEURAL networks

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

TRANSPORTERS for GLUCOSE ABSORPTION

A
  • SGLT-1 (SODIUM GLUCOSE LIKE TRANSPORTER 1)
    into cell with Na+
    (Na+ pumped out basolateral end via Na+-K+ ATPase)
  • GLUT2 into blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

H2O can also be absorbed by TRANSCELLULAR ROUTE using which AQUAPORINS

A
  1. AQP10
  2. AQP3
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Na+ (and cl-) diffuses down TIGHT JUNCTIONS and what follows

A

H2O

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

what is SECRETED into INTESTINAL LUMEN from CRYPT cells

A

Ca2+

-> draws Na+ through tight junctions (NaCl)
-> H2O follows

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

ION CHANNELS ACTIVATED /opened for INTESTINAL FLUID SECRETIONS (CRYPT cells)

A
  • NA+/K+ ATPase
  • NA+/K+/ 2CL- CO-TRANSPORTER
    sodium potassium dichloride cotransporter (2cl-, Na+, K+ in)
  • K+ CHANNEL
  • CL- CHANNEL
  • CL- INTO LUMEN

(Na+ and H2O through tight junctions)

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

what cause the ACTIVATION and OPENING of CHANNELS in INTESTINAL CRYPT CELLS

A

ACH
-> IP3 -> intracellular CA2+ Release

VIP binding to G-PROTEIN COUPLED RECEPTOR
- cAMP

allow Cl- out

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

what happens in HYPERMOTILITY type of DIARRHOEA

A

Transport is TOO FAST in intestines for Absorption

17
Q

Causes of HYPERMOTILITY type of DIARRHOEA

A

HIGH FIBRE DIET

DIABETES - ADRENERGIC NEUROPATHY

18
Q

what happens in OSMOTIC type of DIARRHOEA

A

NON-SOLUTE ABSORPTION

  • ENZYME DEFFICIENCY
    or
  • VILLOUS ATROPHY

so particular solute not absorbed or total reduction in nutrient absorption

19
Q

When do you get OSMOTIC type of DIARRHOEA

A

LACTASE DEFICIENCY (cant break down LACTOSE)

COELIAC (sprue) DISEASE
(gluten sensitive)

20
Q

what happens in DEFECTIVE TRANSPORT type of DIARRHOEA

A

NA+ or CL- TRANSPORTERS are ABSENT

  • electrolytes stay in gut lumen so WATER not absorbed

caused by rare congenital defects

21
Q

what happens in SECRETORY type of DIARRHOEA

A

NET SECRETION > NET ABSORPTION

due to
INFLAMMATION
blood HORMONES (ie pancreas secrete VIP, Thyroid - calcitonin)
TUMOURS (secrete)
ENTEROTOXINS
VIRUSES/PARASITES

22
Q

TRAVELLERS DIARRHOEA caused by

A

BACTERIA ,VIRUSES, PARASITES

FOOD or WATER BORNE

23
Q

EXAMPLE of BACTERIA that commonly causes DIARRHOEA

A

VIBRIO CHOLERAE - CHOLERA TOXIN (on chr. 1)

24
Q

structure of CHOLERA TOXIN

A

1X ALPHA SUB-UNIT (large, heavy)

5X Light BETA SUB-UNITS

25
Q

what happens to CHOLERA TOXIN INTRACELLULAR

A
  1. taken up into ENDOSOME
  2. through GOLGI
  3. into ER
  4. ALPHA SUB-UNIT CLEAVED by furin enzyme
  5. ALPHA SUB-UNIT passed out of pore into CYTOSOL
  6. ACTIVATES ADENYLATE CYCLASE
  7. converts ATP into cAMP
  8. OPENS CHANNELS so CL- SECRETION
    -> drives Na+ and H2O through Tight Junctions

HYPERSECRETION NACL, NAHCO3, LOTS H2O

26
Q

what does CHOLERA TOXIN ACTIVATE INTRACELLULAR (second messenger)

A

cAMP

  • by activating ADENYLATE CYCLASE with ALPHA Sub-Unit
27
Q

what on CELL SURFACE allows for CHOLERA TOXIN ENDOCYTOSIS

A

GM1
- glycolipid structure that interacts with BETA SUB-UNITS of CHOLERA TOXIN

28
Q

what does GM1 on cell surface INTERACT with on the CHOLERA TOXIN

A

BETA SUBUNITS

29
Q

when CHOLERA TOXIN INTRACELLULAR, what does the ALPHA 1 SUB-UNIT HYDROLYSE for activation of ADENYLATE CYCLASE

A

HYDROLYSES NAD+
into ADP-RIBOSE

which is transferred by alpha 1 onto G-PROTEINS
(GDP)

30
Q

with CHOLERA TOXIN how are the ION CHANNELS and why

A

ALWAYS OPEN

  • CONSTITUTIVE ACTIVATION of ADENYLATE CYCLASE

as ADP-RIBOSE on G-PROTEIN is IRREVERSIBLY ACTIVATED

therefore HYPERSECRETION

31
Q

ORAL REHYDRATION THERAPY contains:

A

WATER
ELECTROLYTE (ie NaCl, KCl)
GLUCOSE

for transport of nutrients and water absorption
& replacement of lost K+

Gastrointestinal (19 decks)

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