HUBS192 Lecture 18 - Oxygen and Carbon Dioxide Exchange Flashcards

1
Q

what is the equation for how much air we breathe in and out?

A
  • Vf = Vt x f
  • respiratory minute volume = tidal volume (breathing strength) x respiratory rate (breathing speed)
  • (L/min) = (L/breath) x (breaths/min)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is respiratory minute volume?

A

volume of air respired (breathed in and out) per minute in L/min

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

what is the dead space (Vd)?

A

air in conducting portion of the respiratory system (anatomic dead space)
-volume of air trapped in the bronchial tree that does not interact with the alveoli

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

what is alveolar ventilation?

A

the amount of air that is getting in the alveoli that can be used in gas exchange per time

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

what is the equation for alveolar ventilation?

A
  • Va = (Vt - Vd) x f
  • Alveolar ventilation = (tidal volume (breathing strength) - dead space (the air that can’t be used) x respiratory rate (breathing speed)
  • (L/min) = ((L/breath) - L/breath)) x (breaths/min)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is not helpful to increasing alveolar ventilation?

A

tiny rapid breaths are not helpful

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

why are tiny rapid breaths not helpful in increasing alveolar ventilation?

A

because tidal volume is small its not much more than the dead space therefore trapping the fresh air within the dead space and not coming in contact with the alveoli
-respiratory rate is increased

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

how do you increase alveolar ventilation?

A
  • increase tidal volume
  • keep respiratory rate highly constant
  • results in a negligable dead space
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is daltons law?

A

the pressure of a mixture of gases is the sum total of the pressures of each individual gas

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

what is the largest component of air?

A

nitrogen

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

what is the ratio of gases when inhaling air?

A
  • mostly nitrogen (nitrogen content in the alveoli is relatively the same)
  • quite a lot of oxygen (oxygen content in the alveoli is very low)
  • almost no carbon dioxide or water vapour
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the ratio of gases when exhaling air?

A
  • mostly nitrogen
  • oxygen is decreased
  • carbon dioxide is increased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the goal of moving gas across the membranes?

A

the goal is to move gas back and forth between the alveoli and the capillaries (CO2 and O2)

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

where is inhaled oxygen transported?

A

transports inhaled oxygen into the capillaries

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

where is carbon dioxide (CO2) transported?

A

transports carbon dioxide into the alveoli to be exhaled

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

how do gases move across the membranes?

A

gases move across the membranes between the alveoli and the capillaries by diffusion

17
Q

what 3 things determine the rate of diffusion of gases?

A

1) surface area of the membranes
2) thickness of the membranes
3) pressure difference between the two sides

18
Q

what creates the high surface area for gas exchange?

A

bulbous structure of alveoli and the high density of capillaries

  • creates lots of air pockets
  • surface area as large as a tennis court
19
Q

what is emphysema?

A

disease characterised by diction of the alveolar spaces and destruction of the alveolar walls

20
Q

what is the result of emphysema?

A

reduction in surface area means less contact between the air and capillaries, oxygen exchange is greatly reduced

21
Q

what is the blood air barrier mostly composed of?

A

mostly composed of the alveolar and capillary walls

22
Q

what is the relationship between the distance between of the alveolar air and the blood?

A

small distance between the alveolar air and the blood

-affects diffusion

23
Q

what are the 3 key determinants of how much alveolar oxygen we have at any given moment?

A

1) atmospheric oxygen
2) alveolar ventilation
3) blood oxygen (amount of exchange that Is occurring)

24
Q

what is the relationship between exercise and blood oxygen?

A

exercise depletes blood oxygen

25
what is happening in the body at low activity in terms of oxygen consumption and oxygen in venous blood?
- reduced oxygen consumption | - higher levels of oxygen in the venous blood
26
what is happening in the body at high activity in terms of oxygen consumption and oxygen in venous blood?
- increased oxygen consumption | - lower levels of oxygen in the venous blood
27
what are the things that 3 determine how much alveolar carbon dioxide we have at any given moment?
1) atmospheric CO2 2) alveolar ventilation 3) blood CO2
28
how do gases diffuse in terms of their pressure gradient?
gases diffuse down their pressure gradient