Lecture 20 Flashcards

1
Q

We bring in _________ from the _______ which goes into the _______ from the _________ and we need to extract ________ from the exercising lungs

A
O2
atmosphere
blood
lungs
CO2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which is the major fueling pathway for our exercising skeletal muscles?

A

oxidative phosphorylation

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

What are the three main goals of the respiratory system during exercise?

  1. ensure that the _______ _______ of O2 (________) in our _______ is well maintained to allow adequate ________ supply to our _________ muscles
  2. to ________ metabolic and ____________ CO2 to maintain the partial pressure of ________ (_______) in our _________
  3. to assist in the _______ of the metabolic ______ produced during ________ intensity exercise
A
  1. ensure that the partial pressures of O2 (PaO2) in our arteries is well maintained to allow adequate O2 supply to our exercising muscles
  2. to eliminate metabolic and non-metabolic CO2 to maintain the partial pressure of CO2 (PaCO2) in our arteries
  3. to assist in the buffering of the metabolic acids produced during high intensity exercise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

At sea level, the PO2 in the air is about ________ mmHg by by the time it reaches the alveoli, it is about ________mmHg.

A

159

105

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

O2 diffuses into the lung _________ and then binds to ___________

A

capillaires

Hb

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

What fueling pathway is used in the lungs? Describe this in terms of the PO2.

A

Oxidative phosphorylation in the lungs which uses O2

The PO2 is decreased in the muscle (40mmHg)

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

How much O2 do muscles extract at rest and how does this change during exercise?

A

at rest: about 60mmHg

during exercise: we extract much more

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

If there is 20mL of O2 per 100mL of blood in the artery and 4-5mL diffuses into the muscles, how much is in 100mL of blood in the vein?
Is this at rest or during exercise?

A

15-16mL

this is at rest

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

If there is 20mL of O2 per 100mL of blood in the artery and 15mL diffuses into the muscles, how much is in 100mL of blood in the vein?
Is this at rest or during exercise?

A

5mL

this is during exercise

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

What are the two main CO2 sources?

A

metabolic and non-metabolic pathways

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

What are the two metabolic pathways where CO2 comes from?

A

Glucose + 6O2 → 30 ATP + 6CO2 +6H2O

Palmitate + 23O2 → 108 ATP + 16 CO2

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

What is the non-metabolic pathway that CO2 comes from?

A

H+ + HCO3 →H2CO3 → CO2 + H2O

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

After the blood has gone through the ________ beds, we have a decrease in _________ in the __________ system that needs to be replenished in the __________ system. We also need to expel _____. During exercise, there is an increase in ________

A
muscle
PO2
venous
pulmonary
CO2
ventilation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What two things increase what we increase ventilation?

A
  • tidal volume

- breathing frequency

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

By how many times does the tidal volume increase from rest to maximal exercise?

A

it is 8 times greater

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

By how many times does the breathing frequency increase from rest to maximal exercise?

A

is it 4 times greater

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

By how many times does the ventilation increase from rest to maximal exercise?

A

it is 32 times greater

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

What controls the increase in ventilation during exercise?

A

both neural and chemical pathways

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

How does the respiratory rate change in anticipation for exercise?

A

it starts to increase so it is greater than at rest but less than during exercise

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

Explain why exercise is hard at first and then it gets easier

A

it gets easier because the neural control settles down and the chemical control takes over

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

Fine turning of ventilation during steady exercise is by what? give examples

A

by blood borne substances such as CO2, pH/H+

22
Q

What level does the chemical control occur?

A

at the level of the brainstem

23
Q

What are the chemical stimulation for chemical control of ventilation?

A

H+ or CO2

24
Q

Describe the order of energy use when exercising

A
  • ATP stores
  • ATP-CP system
  • lactic acid system
  • aerobic system
25
Q

Describe the lactic acid system and how it acts on the central chemoreceptors

A

Lactate from glycolysis leads to activation of H+ levels which acidifies the blood. This is rapidly buffered by HCO3 which makes CO2. This diffuses into the CSFluid which gets converted back to H+. This acts on the central chemoreceptors to tell the lungs to increase ventilation rate as CO2 level in the blood is too high

26
Q

We have to increase ventilation to get rid of what?

A

CO2

27
Q

The predominant energy system to produce ATP at any one time depends on what three things?

A
  • the intensity of the exercise
  • duration of the exercise
  • how fit you are
28
Q

Explain how the intensity of the exercise affects the predominant energy system to produce ATP

A

The more intense the exercise, the more muscle glycogen and more creatine phosphate will be used and so we are relying on more anaerobic systems

29
Q

Explain how the duration of the exercise affects the predominant energy system to produce ATP

A

If the exercise is two hours, we use aerobic system.

If we are going up a hill, we might switch back to anaerobic for that amount of time

30
Q

Explain how fitness affects the predominant energy system to produce ATP

A

If you have a higher level of aerobic fitness, it will take an athlete longer to rely on their anaerobic system and so the faster you can go

31
Q

As workload increases, so does what?

A

ventilation

it increase up until a certain point based on intensity

32
Q

The harder you are working, the faster you are _________ and so the more _______ you require

A

breathing

tidal volume

33
Q

At first, there is a ________ relationship between workload and ventilation and but then we reach a point and we get to an ___________ relationship and then we reach _________

A

linear
exponential
exhaustion

34
Q

What is the point where the ventilation rate greatly increases? What causes it?

A

This is the anaerobic threshold and it is caused by an increase in CO2 level.

35
Q

What does the anaerobic threshold show?

A

This is the start on non-sustainable exercise where your body can no longer rely on O2 systems to meet the ATP demands so you start to use anaerobic system

36
Q

What is the modern term for the anaerobic threshold is what?

A

functional threshold power

37
Q

Define the functional threshold power

A

This is the maximum intensity an athlete can hold without accumulation of lactate, or the fatigue that goes along with that phenomenon

38
Q

Why did the term “anaerobic threshold” get changed to “functional threshold power”?

A

Because it became apparent from research that there is no point in time when the aerobic (with O2 systems) switch over to a level of intensity where O2 is simply not used (anaerobic) because at all times, all the systems are being used.

39
Q

What four things increase at the anaerobic threshold?

A
  1. ventilation rate
  2. CO2
  3. O2
  4. blood lactic acid
    There is an increase in the blood lactate concentration. It is too high that we can no longer buffer the H+ well enough so the CO2 starts to accumulate and you start to increase your ventilation rate
40
Q

What two things is the functional threshold power dependent on?

A
  • Aerobic system : how quickly lactate can be removed

* Anaerobic system: how much lactate is produced

41
Q

We move to anaerobic system when what?

A

When we can’t get enough O2 to the skeletal muscle to sustain exercise aerobically

42
Q

When the intensity gets even higher than the anaerobic threshold, we move to what threshold. Describe this

A

The lactate threshold
When the lactate starts to build up in our systems, we run out of glycogen and creatine phosphate stores very quickly and we have to slow down and our exercise stops. We have now used up all of our different creatine phosphate stores and our glycogen stores and we can’t use our anaerobic system anymore. We have to stop or slow right down to our aerobic systems are dominant.

43
Q

What is the VO2 max?

A

This is the point at which we have to stop and we can’t sustain the exercise intensity level anymore
It is the point when the maximum amount of O2 is getting to our skeletal muscles. We are using aerobic systems but very much reliant on anaerobic systems. We are using all of our different fuel sources to try and sustain this huge work effort.

44
Q

How does aerobic fitness affect how long you use each energy system for?

A

The more aerobic fitter you are, the further along the exercise intensity you can maintain relying on O2 systems before you switch over to needing the anaerobic systems.

45
Q

How does the anaerobic fitness effect how long you use each energy system for?

A

You can get up to really intense workouts for about 2 minutes (as opposed to 1 minute in untrained people) before you use up the glycogen and creatine-phosphate stores are run out and anaerobic system has to take over and slow you down.

46
Q

What can you do to improve your aerobic threshold?

A

endurance training

47
Q

What can you do to improve you anaerobic fitness?

A

you can do interval training or heel-work to improve lactate threshold and therefore your anaerobic threshold

48
Q

How do you measure VO2 max?

A

You put an athlete through that workload:
- at lower workload intensities, their aerobic system can maintain the pace
- as you increase the treadmill or resistance on the bike, the anaerobic system eventually takes over and then you keep increasing it until the athlete can no longer do it because all the creatine-phosphate and glycogen stores have been used up.
At this point, we measure the amount of O2 that the athlete is consuming in ml/kg/min.
The higher the VO2 max, the fitter the athlete

49
Q

What is the range of VO2 max for a healthy 20 - 29 yr old female?

A

40-49

50
Q
Which of the following sports is an anaerobic activity?
• Baseball
• Marathon running 
• Weightlifting
• 1500m running
A

weightlifting