Brainscape's Knowledge GenomeTM

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


See full index

AFN Pathophysiology > Lecture 2 > Flashcards

Lecture 2 Flashcards

1
Q

1/3 of total body fluid

A

Extracellular fluid (ECF)

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

2/3 of total body fluid

A

Intracellular fluid (ICF)

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

What percentage of body weight is water?

A

55-65%

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

(T/F) Diffusion is a type of active transport

A

False

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

random movement/distribution of dissolved particles

A

Diffusion

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

Type of diffusion consisting of movement across lipid portion of membrane

A

Simple Diffusion

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

Type of diffusion consisting of movement through water filled membrane channel

A

Facilitated diffusion

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

Type of diffusion consisting of movement using carrier molecules

A

Facilitated diffusion

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

What does dn stand for in the diffusion rate equation?

A

number of molecules inside cell (mol)

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

What does dt stand for in the diffusion rate equation?

A

diffusion time (sec)

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

What does P stand for in the diffusion rate equation?

A

permeability constant for a particular molecule (cm/sec)

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

What does A stand for in the diffusion rate equation?

A

surface area of the cell membrane (cm2)

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

What does C stand for in the diffusion rate equation?

A

concentration of diffusing molecule (mol/cm3)

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

What does X stand for in the diffusion rate equation?

A

width of cell membrane (cm)

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

What does dn/dt stand for in the diffusion rate equation?

A

Diffusion rate

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

In the context of facilitated diffusion, what does Vmax mean?

A

The saturation constant

(when carrier proteins are at max capacity and can no longer transport additional solute)

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

In the context of the facilitated diffusion equation, what does K mean?

A

constant determining speed of saturation (mol/cm4)

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

Which type of diffusion reaches a plataeu in diffusion rate?

Passive or facilitated?

A

Facilitated

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

Movement of solute against its concentration gradient

A

Active transport (aka primary active transport)

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

Coupling one molecule to the transport of another. May be with or against the concentration gradient

A

Secondary active transport

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

This type of active transport is extremely important in the transport of molecules across the renal and intestinal epithelium

A

Secondary active transport

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

Net diffusion of water across a membrane

A

Osmosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Movement of water driven by osmosis

A

Osmotic flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Indication of force of pure water moving into a solution
with higher solute concentration

A

Osmotic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

(T/F) Clinically, Osmolarity = Osmolality

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the equation for manually calculating osmolarity/osmolality?

A

2[Na+] + (glucose/18) + (BUN/2.8)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Calculate the osmolarity/osmolality:

Na = 140, Glucose = 90 and BUN = 12

A

289

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

This term is defined as the effect of osmotic solutions on cell volume

A

Tonicity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Solution that does not cause osmotic flow across membrane (normal saline, 0.9%NaCl)

A

Isotonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Solution that causes osmotic flow into cell
• Patho Example: hemolysis (hemo-, blood + lysis, loosening)

A

Hypotonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Causes osmotic flow out of cell

Patho example: crenation of RBCs

A

Hypertonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Know how to read a Darrow-Yennet Diagram

A

Know it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

For ions to move across a membrane, they must have 2 things available. What are they?

A

A gradient (driving force)

A path to move on (its almost impossible for ions to move across a lipid membrane)

34
Q

In regards to ion movement, which type of gradient is more sensitive: Chemical or electrical?

A

Electrical

35
Q

When the membrane potential is 0, or there is no electrical gradient, the configuration of ions is considered to have the highest _______

A

entropy

36
Q

In regards to membrane potentials, what does Vm stand for?

A

Voltage across the membrane

37
Q

The unit of measurement for a membrane potential, in other words the potential energy of an ion across the cellular membrane.

A

Vm (voltage)

38
Q

Does a + Vm indicate a greater membrane potential than a - Vm?

A

No

(doesn’t matter if the charge is + or - because there is still charge which indicates polarity)

39
Q

(T/F) In physiological cells, very small movements of ions induce big changes in the Vm

A

True

40
Q

When discussing membrane potentials in physiology, the ________ compartment is always considered the reference.

A

intracellular

41
Q

A ________ _________ arises when there is a difference in charge across the membrane

A

membrane potential

42
Q

A(n) _________ Potential is the difference in charge (measured in millavolts (mV)) across the membrane that exactly offsets the energy in an ion’s concentration gradient

A

Equilibrium

43
Q

(T/F) Equilibrium potentials are specific to each ion

A

True

44
Q

Also called “Nernst Potential” or “Reversal Potential”

A

Equilibrium potential

45
Q

What is the Nernst equation for calculating equilibrium potentials?

A

Eion = 61mV/z log ([Ion]o/[Ion]i)

z = # of valence electrons specific to the ion

46
Q

If a K+ ion has an Ek = -94mV (this means that intracellularly a charge of -94mV is needed to counteract the + charge created from the small extracellular concentration of K+), What would theoretically happen to Ek if the extracellular K+ is increased to 20mM (this would be altering the Nernst equation components)?

A

Ek will decrease

(This question is testing knowledge of how the Nernst equation works. All ions have a specific, set equilibrium potential (Eion) for the normal concentrations in a homeostatic human body. Under pathologic conditions, or when altering EC concentrations, Eion can change due to concentration gradient changes.

47
Q

(T/F) The farther away Vm is from Eion, the lesser the driving force is on that ion

A

False

(greater the driving force)

48
Q

Which ion has the greatest driving force on it?

A. K+ at Vm of -62mV (EK = -94mV)
B. Na+ at Vm of -62mV (ENa = +62mV)
C. Cl- at Vm of -62mV (ECl = -62mV)

A

B. Na+

(greater difference between Vm & ENa)

49
Q

A measure of the ability of an ion to diffuse across the membrane (due to open ion channels)

A

Conductance (gion)

50
Q

the inverse of resistance

A

conductance (gion)

51
Q

The higher the conductance of an ion, the _____ Vm will be to that ion’s equilibrium potential (closer or farther?)

A

closer

52
Q

Why is K+ conductance (gion) so much higher than the other ions?

A

At rest, most ion channels that are open conduct K+ (these channels are called K+ leak channels)

53
Q

(T/F) At rest, most ion channels that are open conduct K+

A

True

54
Q

What is the resting membrane potential within a homeostatic human body?

A

-70mV

55
Q

Why is the resting membrane potential highly negative?

A

The inside of the cell needs to be at a highly negative charge to repel the extremely low concentration of extracellular K+ ions that can easily pass through the open ion channels. This, paired with the fact that K+ has a much higher conductance than the other ions, lead to the resting membrane potential being closer to the K+ Nuerst potential (Eion).

(Remember under normal homeostasis, the extracellular K+ concentration is 4mM & intracellular K+ concentration is 140mM)

56
Q

A complex of proteins that come together to form a water-filled pore that spans the cell membrane

A

Ion channel

57
Q

Type of ion channel that open or close when when Vm changes

A

Voltage-gated

58
Q

Type of ion channel that open or close when ligand binds to channel complex (receptors)

A

Ligand-gated

59
Q

Na+ channels open and close very ______

A

quickly

60
Q

K+ channels open ______, and many
types stay open long

A

slower

61
Q

Ca++ channels open and close ______

A

slowly

62
Q

Vm - Eion = ?

A

NDF (Net driving force)

This is the current when ions move through channels. Magnitude depends on NDF.

63
Q

When channel opens, ionic current direction and magnitude depends on the ____ ______ ______

A

net driving force

64
Q

Term for the Vm required for conformational change in
ion channel protein structure (aka Vm required to open an ion channel)

A

Threshold

65
Q

When ________ is reached, action potentials are initiated

A

threshold

66
Q

What is the threshold for all ion gates to open?

A

-50mV

67
Q

The current Vm is -55mV. Are all ion gates open?

A

No

(Vm needs to be -50mV or lower (more positive))

68
Q

The n-gate is in the channel for what ion?

A

K+

69
Q

The m-gate and h-gate are in the channel for what ion?

A

Na+

70
Q

Which is the slowest voltage gate channel?

A

n-gate

(for K+ ions)

71
Q

(T/F) Leak channels are open at resting membrane potential

A

True

72
Q

(T/F) Voltage-gated channels are open at resting membrane potential

A

False

73
Q

Different ion channels are involved in different phases of the _____ _______

A

action potential

74
Q

What molecule binds to the nicotinic receptor to exceed the threshold of the voltage-gated ion channels, therefore inducing a current and muscle contraction d/t increased Na+ & K+ permeability?

A

Acetylcholine

75
Q

During an action potential, does K+ enter or leave the cell?

A

Leaves the cell

76
Q

During an action potential, does Na+ enter or leave the cell?

A

Enters the cell

77
Q

Responsible for muscle contraction

A

Action potential

78
Q

Action potentials will be the same magnitude every time unless _________ potentials change

A

equilibrium potentials

79
Q

Common cause of equilibrium potential changes

A

Extracellular ion concentration changes (aka serum ion levels)

80
Q

During a cardiac action potential, does Ca2+ enter or leave the cell?

A

Enter

81
Q

The ‘lethal’ ingredient in lethal injection is a bolus of KCl. Why is this lethal?

A

The extreme extracellular concentration of K+ Prevents the cell from depolarizing because K+ does not want to leave the cell. The cells cannot re-establish resting membrane potential.

AFN Pathophysiology (6 decks)

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