Epithelial Transport Flashcards Preview

M2M Unit III > Epithelial Transport > Flashcards

Flashcards in Epithelial Transport Deck (51):
1

At rest, the apical _____ channels are closed.

Cl-

1

What kinds of metabolic waste molecules are non-volatile?

urea and protons

2

_____ cannot maintain large energy gradients because solutes and water leak back across the epithelium through the pericellular shunt.

Leaky epithelia

2

In the lungs, ____ diffuses passively from blood to air.

CO2

3

How does someone get cystic fibrosis?

it's genetic

3

How do the kidneys filter waste?

the epithelial cells lining the tubules reabsorb the things that it wants to keep (glucose, salts, bicarbonate, etc)

4

Each day the cells in an adult human produce about ____ of metabolic waste solute.

15 moles

4

What is Uremia?

urine in the blood

4

Functions of the kidney include excreting non-volatile metabolic wastes and _____.

regulating the composition of virtually all ECF solutes as well as water

5

By keeping the ______ concentration low, the Na/K pump provides the energy to drive a host of secondary transporters.

intracellular sodium ion

5

How are the metabolic waste solutes removed from the body?

fluid exits the lungs; the kidneys do the rest

6

Synonyms for _____ include serosal and peritubular.

basolateral

7

Where are water pumps located in the body?

they don't exist

8

What is the defect in cystic fibrosis?

the Cl- channel is mutated, reducing the epi's ability to secrete serous fluid, causing very thick mucous and infections

9

What does CFTR stand for?

Cystic Fibrosis Transmembrane Conductance Regulator

10

In general, epithelia engaged in _____ are leaky, while those epithelia doing the finishing work are tight.

massive transport of substances

10

A ____ transepithelial voltage would be measured in leaky tight junctions.

lower

11

By keeping the intracellular sodium ion concentration ____, the Na/K pump provides the energy to drive a host of secondary transporters.

low

13

In general, epithelia engaged in massive transport of substances are leaky, while those epithelia _____ are tight.

doing the finishing work

13

How are the GI tract epithelium transporters regulated?

they aren't- they will absorb everything ingested

14

Water always moves passively down _____.

osmotic gradients

15

What is the equation for transepithelial potential difference (transPD)?

TransPD = Vm (Basolateral) – Vm (Apical)

15

How does cholera toxin work?

it locks open the Cl- channels, causing a massive efflux of fluid from the cell

15

Water always moves _____ down osmotic gradients.

passively

17

The _____ is always located on the basolateral membrane.

Na/K pump

18

Synonyms for _____ include mucosal and luminal.

apical

20

What is the key player in secretion of fluid by an epithelial cell?

the Cl- channel

21

The ____ and _____ are examples of sodium-dependent secondary active transport systems.

sugar; amino acid pumps

22

The sugar and amino acid pumps are examples of ______.

sodium-dependent secondary active transport systems

23

Functions of the ____ include excreting non-volatile metabolic wastes and regulating the composition of virtually all ECF solutes as well as water.

kidney

25

The driving force for nearly all transport is the ______.

Na/K pump

27

Leaky epithelia cannot maintain large energy gradients because solutes and water leak back across the epithelium through the _________.

pericellular shunt

29

Name 2 ways a substance can cross the epithelium.

1) entering the epi and exiting the other side 2) pass through the tight junctions via the pericellular shunt pathway

29

Synonyms for basolateral include _____ and ______.

serosal; peritubular

30

A lower transepithelial voltage would be measured in ____.

leaky tight junctions

31

____ always moves passively down osmotic gradients.

Water

33

Epithelial cells transport glucose by ____.

sodium-dependent secondary active transport pumps

35

____ are the main exception to the otherwise universal dependence of epithelial pumping on the Na/K pump.

Protons

36

The Na/K pump is always located on the ______.

basolateral membrane

37

Functions of the kidney include_____ and regulating the composition of virtually all ECF solutes as well as water.

excreting non-volatile metabolic wastes

38

How does Cl- leaking into the lumen pull water with it?

Na+ passively follows Cl-,and the resulting osmotic gradient draws water along with it

40

What is the pericellular shunt pathway?

solutes and water passing in between the epi cells through leaky tight junctions

42

By keeping the intracellular sodium ion concentration low, the _____ provides the energy to drive a host of secondary transporters.

Na/K pump

43

What activates the Cl- channels?

hormones, parasympathetic nerves, pathogens

44

Synonyms for apical include _____ and ______.

mucosal; luminal

45

vasopressin

anti-diuretic hormone

47

How is a sugary snack absorbed by the epithelium?

NaCl leaks from the blood and crosses the leaky tight junctions

48

Each day the cells in an adult human produce about 15 moles of _____.

metabolic waste solute

49

At rest, the apical Cl- channels are _____.

closed

50

Non-epithelial cells transport glucose by _____.

facilitated diffusion

51

Protons are the main exception to the otherwise universal dependence of epithelial pumping on the ____.

Na/K pump