Brainscape's Knowledge GenomeTM

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


See full index

CardioPulm > 11.21 A > Flashcards

11.21 A Flashcards

1
Q

In words, what is cardiac output?

A

the flow of blood out of the left heart and into the aorta

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

As an equation, cardiac output is what?

A

HR x stroke volume

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

What does MAP stand for? What is it?

A
  • mean arterial pressure

- the average pressure in the systemic arteries

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

What is the hemodynamic equivalent of Ohm’s Law that applies to blood flow?

A

flow = (pressure differential)/resistance

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

What is the blood pressure in the right atrium?

A

negligible because it is part of the venous system

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

What does TPR stand for?

A

total peripheral resistance

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

What determines total peripheral resistance?

A

the resistance of the systemic arterioles

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

MAP = ???

A

MAP = CO x TPR = HR x SV x TPR

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

The baroreflex attempts to maintain what?

A

mean arterial pressure

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

The baroreflex works to maintain MAP by altering what two factors?

A

either cardiac output or total peripheral resistance

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

Changes in MAP are detected by what?

A

baroreceptors

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

What are baroreceptors?

A

stretch receptors in the arteries that participate in the baroreflex

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

What happens to baroreflex-related parasympathetic firing when MAP decreases?

A

it decreases

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

What happens to baroreflex-related sympathetic firing when MAP decreases?

A

it increases

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

When parasympathetic firing decreases as part of the baroreflex, what are the physiologic results?

A

decreases parasympathetic firing to the SA node, which is normally inhibitory, disinhibits firing and increases the heart rate

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

Parasympathetic firing to the SA node is usually (inhibitory/excitatory).

A

inhibitory

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

What portion of total body water is in the intracellular fraction?

A

two thirds

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

What portion of total body water is in the extracellular fraction?

A

one third

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

How much of the extracellular body water is interstitial?

A

three quarters

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

How much of the extracellular body water is in the plasma fraction?

A

one quarter

21
Q

How have we determine the distribution of total body water?

A

by injecting a substance that has a known distribution in the fractions, taking a sample of body fluid, and using C=m/V to determine the volume

22
Q

What is the most approximate way to estimate total body water?

A

TBW = 60% of body weight

23
Q

What is the most accurate way to estimate total body water?

A

TBW = 72% of lean body mass = 72% of (body weight - fat weight)

24
Q

How does total body water change with age?

A

infants have more body water and have a different ratio than adults

25
Q

Where is sodium concentration high in total body water?

A

plasma and interstitial

26
Q

Where is potassium concentration high in total body water?

A

in the intracellular fraction

27
Q

Where is calcium concentration higher in total body water?

A

~ 2.5 in plasma and interstitial, 0 in intracellular

28
Q

Describe protein concentration in the different fractions of total body water?

A

highest in intracellular (4), lowest in interstitial (0.2), plasma in the middle (1.2)

29
Q

Total concentration of solutes in the three fractions of total body water are all approximately what?

A

290-305 mOsm

30
Q

What is osmotic pressure?

A

the hydrostatic pressure that prevents water movement from a pure water phase into a solute phase

31
Q

At normal body temp, the relationship between osmotic pressure and solute concentration is roughly what?

A

20 mmHg per mOsm solute difference

32
Q

What is the basis for oncotic pressure?

A

the difference in protein concentration between the interstitial and plasma fractions and that protein is impermeant

33
Q

Oncotic pressure provides the force needed for what?

A

re-absorption of water

34
Q

What happens to capillary pressure across a capillary?

A

resistance increases due to narrowing of the blood vessel and so flow declines and pressure decreases

35
Q

At a capillary, which is greater, the filtration volume or the reabsorption volume?

A

the filtration volume

36
Q

What happens to the the fluid that is filtered at a capillary but isn’t reabsorbed into the venous system?

A

it is taken up into the lymphatic system to be returned to the vascular system

37
Q

What might cause the interstitial pressure to be abnormally high and limit the force for filtration?

A

damage to the lymphatic system that results in fluid remaining in the interstitium

38
Q

What might cause the interstitial oncotic pressure to increase?

A

an inflammatory response that increases vascular permeability and permits protein to leave the vessels and enter the interstitium

39
Q

In the first half of a capillary, net filtration occurs because what is greater than what?

A

capillary pressure is greater than oncotic pressure

40
Q

In the second half of a capillary, net absorbtion occurs because what is greater than what?

A

oncotic pressure is greater than capillary pressure

41
Q

How is oncotic pressure that drives water into cells counteracted?

A

by a Na/K pump that changes the solute concentration gradient

42
Q

What is tonicity?

A

the property defined by how the volume of a cell changes when the cell is placed in a solution

43
Q

How does the rate of water movement compare to the rate of permeant solute movement across a semipermeable barrier?

A

water moves much faster than any solute

44
Q

What happens to a RBC placed in an iso-osmotic but hypotonic solution of a permeant solute like urea?

A

it will swell until it lyses

45
Q

What happens to a RBC placed in a hyperosmotic but hypotonic solution of permeant solute like urea?

A

the cell will initially shrink as water rapidly leave the cell but will then swell and burst as urea moves into the cell and water follows

46
Q

What happens to a RBC placed in a hyperosmotic but isotonic solution?

A

the cell will initially shrink and then return to its original size

47
Q

IV saline is ___osmotic and ____tonic.

A

isoosmotic and isotonic

48
Q

Because saline is isoosmotic and isotonic, it will have what effects on the various body fluid fractions?

A

it will increase extracellular volume and not change the intracellular volume

49
Q

5% dextrose will have what effects on the various body fluid fractions?

A

it will increase both the extracellular and intracellular volumes

CardioPulm (31 decks)

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