RS Lec 5 Flashcards

1
Q

pressure exerted by gas molecules due to

A

their motion, motion exerts pressure

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

pressure increases as

A

temp increases, conc increases

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

dalton’s law

A

total pressure= sum of individual pressures (partial pressures)

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

diffusion

A

rate of transfer of gas through tissue/unit time

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

diffusion is proportional to (3)

A
  • tissue area
  • difference is gas partial pressure
  • diffusion constant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

diffusion is inversely proportional to (1)

A

-tissue thickness

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

solubility of CO2 and O2

A

carbon dioxide solubility is much higher than O2 but have similar molecular weight, co2 diffuses 20x faster than o2

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

Diffusion constant (D) proportional

A

-to solubility/ square root (molecular weight)

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

henry’s law

A

-amount of gas dissolved in a liquid is directly proportional to partial pressure of gas in equilibrium

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

concentration of gas (in liquid) =

A

pressure (only gas dissolved in liquid contributes to partial pressure) x solubility

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

PO2 in air > PO2 in alveoli because (3)

A
  • humidification of air in respiratory tract ↓
  • loss of O2 to blood diffusion ↓
  • mixing of inspired air with alveolar air (functional residual capacity) ↓
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what determines alveolar PO2? (4)

A
  • PO2 in atmosphere
  • alveolar ventilation (Va)
  • metabolic rate
  • perfusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what determines alveolar PCO2?

A
  • PCO2 in atmosphere
  • alveolar ventilation (Va)
  • metabolic rate
  • perfusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

increasing alveolar ventilation will

A
  • increase alveolar PO2

- decrease alveolar PCO2

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

Increasing metabolic rate will

A
  • decrease alveolar PO2

- increase alveolar PCO2

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

partial pressure of gas in alveoli determine

A

-arterial levels,

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

cardiac output

A

-volume of blood pumped by heart per minute (ml blood/min)

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

systemic circulation

A

-high pressure system needed to deliver blood to body (high resistance system)

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

pulmonary circulation

A

-low pressure system needed to deliver blood to lungs (high pressures= lung edema)

20
Q

systemic circulation and pulmonary circulation

A

flow systemic circulation = flow pulmonary circulation

21
Q

pulmonary low pressure system

A

-need to pump blood only to the top of the lung, important for avoiding rupture of resp. membran + edema formation

22
Q

pulmonary low resistance system

A

-R is less than 1/10 of that in the systemic circulation due to: shorter and wide vessels

23
Q

pulmonary high compliance vessels

A
  • higher number of arterioles with low resting tone
  • due to thin walls and paucity of smooth muscle, can accept large amount of blood
  • can dilate in response to modest increases in arterial pressure
24
Q

pulomonary blood volume

25
capillary blood volume
70 ml at rest | 200 ml during exercise
26
time blood passes through pulmonary capillaries
- at rest: 0.75 s at rest | - cardiac output increases: 0.3 s
27
if capillary pressyre falls below alv pressure
capillaries close off, diverting blood to other pulmonary capillary beds with higher pressures.
28
air should be delivered to regions with
blood flow and vice versa
29
ventilation/perfusion (V/Q) ratio
balance between lung ventilation/ lung perfusion | -affects alv. arterial levels of oxygen + carbon dioxide
30
lung ventilation
O2 ATM --> alveoli/ CO2 alveoli --> ATM
31
lung perfusion
O2 alveoli --> blood/CO2 blood --> alveoli
32
Increase in ventilation
- PO2 + PCO2 in alveoli ≈ PO2 + PCO2 in ATM
33
Increase in perfusion
- PO2 + PCO2 in alveoli ≈ PO2 + PCO2 in mixed-venous blood
34
high V/Q ratio
-lack perfusion (alveolar dead space)- aire not reaching the blood
35
low V/Q ratio
-lack ventilation (airway obstruction --> shunt)
36
local V/Q ratio determines
-local alveolar PO2 + PCO2
37
top of the lungs V/Q
- high V/Q
38
ventilation is greatest
at bottom of the lung
39
perfusion is greatest
at the bottom of the lung (depends on gravity and posture)
40
V/Q is not
constant/uniform in healthy lung
41
apical V/Q
3 x V/Q
42
basal V/Q
0.6 x V/Q (closer to ideal)
43
pulmonary hypoxic vasoconstriction
-response of pulmonary capillaries to low O2, diverts blood to oxygen rich alveoli
44
local perfusion decrease to match local decrease in ventilation
↓ air flow= ↓ PO2 (alveoli) = vasoconstriction= ↓ blood flow
45
local ventilation decrease to match local decrease in perfusion
↓ blood flow= ↓ PCO2 (alveoli) = bronchoconstriction = ↓ air flow