Review

Question 1

Sympathetic nerve activity

Answer 1

Increase HR
Increase SV
Increase CO
Increase flow for venous return
Constrict arterioles (decrease conductance)

Question 2

Parasympathetic nerve activity

Answer 2

Decrease HR

Question 3

Metaboreceptors

Answer 3

Sense changes in metabolites (H+ and Pi)
If metabolites increase, it increases
Activate the medulla

Question 4

Feedback control

Answer 4

Metaboreceptors
Baroreceptors

Question 5

Feedforward control

Answer 5

Mechanoreceptors
Motor outflow/drive
(both activate medulla)

Question 6

Baroreceptor

Answer 6

Sense changes in MAP
Increase with increasing blood pressure
Inhibit the medulla

Question 7

Medulla

Answer 7

Activates SNA
Inhibits PSNA

Question 8

What happens to arterioles with increasing intensity?

Answer 8

Dilation

Question 9

Blood flow and metabolism

Answer 9

Blood flow increases in proportion to metabolism

Question 10

Theory 1: The vasodilator hypothesis

Answer 10

As metabolism increases so do the bi-products (vasodilators) such as extracellular K+, adenosine, CO2, Lactate and H+
These cause vasodilation which cause increased blood flow

Question 11

Theory 2: O2/nutrient lack theory

Answer 11

Decreased O2 availability causes there to be less ATP in the arterioles and therefore smooth muscle relaxation occurs
This causes increased dilation and conductance = Increased blood flow

Question 12

Ways to increase VO2 max

Answer 12

1. Increase blood flow, increase CO, increase DO2
2. Increase O2 extraction by increasing CaO2
3. Increase capillary density

Question 13

The impact of hypoxia on a-vO2 difference

Answer 13

Decreases due to decreased CaO2

Question 14

Ventilation

Answer 14

Increases PaO2
Inhibits PaCO2

Question 15

PaO2

Answer 15

Inhibits peripheral chemoreceptors

Question 16

PaCO2

Answer 16

Activates peripheral chemorecptors

Question 17

H+

Answer 17

Directly activates both peripheral and central chemoreceptors

Question 18

Feedback control of ventilation

Answer 18

Peripheral chemoreceptors and central chemoreceptors

Question 19

Feedforward control of ventilation

Answer 19

Mechanoreceptors and motor outflow
Activate the respiratory control centre
Triggers ventilation

Question 20

Key characteristics of substrate use during exercise

Answer 20

1. Increasing intensity increases carbohydrate metabolism
2. Increasing duration increases fatty acid metabolism
3. Training increases fatty acid metabolism at a given intensity

Question 21

Increased intensity and increased carbohydrate metabolism

Answer 21

Increased intensity increases ADP
ADP activates glycolysis which triggers the PDH reaction to provide acetylCoA for the TCA cycle

Question 22

Carbohydrate metabolism

Answer 22

The PDH reaction produces CO2 (pyruvate to acetyl CoA)
High maximal power
If this increases RER increases

Question 23

Increased duration and training and increased fatty acid metabolism

Answer 23

Fat metabolism creates Acetyl CoA via beta oxidation which can enter the Krebs cycle
Increases aerobic ATP production and decreases outflow from ADP
Less ADP= less activation of glycolysis
Less reliance on carbohydrate metabolism

Question 24

Fatty acid metabolism

Answer 24

Low maximal power
Creation of acetyl CoA vis beta oxidation

Question 25

Respiratory exchange ratio

Answer 25

VCO2/VO2 Carbohydrate metabolism increases the ratio Fatty acid metabolism decreases the ratio

Question 26

What is RER?

Answer 26

Ratio between the volume of CO2 being produced by the body and the amount of O2 being consumed

Question 27

Purpose of RER?

Answer 27

Gives us an indication as to whether the body is operating aerobically or anaerobically