Unit 3 Test

Question 1

Sympathetic nerve activity

Answer 1

• Increase in HR
• Increase in SV
• Increase in CO
• Increase in flow for venous return
• Constrict arterioles, decrease conductance

Question 2

Parasympathetic nerve activity

Answer 2

• Decrease in HR

Question 3

Metaboreceptors

Answer 3

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

Question 4

Feedback control

Answer 4

• Metaboreceptors
• Baroreceptors

Question 5

Feedforward control

Answer 5

• Mechanoreceptors
• Motor outflow/drive
• Both activate the medulla

Question 6

Baroreceptor

Answer 6

• Sense changes in MAP
• Increase with increasing blood pressure
• Inhibits the medulla

Question 7

Medulla

Answer 7

• Activates SNA
• Inhibits PNA

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 causes
  increase in blood flow

Question 11

Theory 2: O2/ nutrient lack theory

Answer 11

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

Question 12

Sub-maximal exercise in hypoxic air

Answer 12

• DO2 can be restored due to a large enough
  compensatory increase in dilation and then
  blood flow

Question 13

Peak exercise in hypoxic air

Answer 13

• DO2 can not be fully compensated for an increase
  in blood flow

Question 14

Ways to increase VO2 max

Answer 14

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

Question 15

The impact of hypoxia on a-vO2 difference

Answer 15

• Decreases due to decreased CaO2

Question 16

Ventilation

Answer 16

• Increases PaO2
• Inhibits PaCO2

Question 17

PaO2

Answer 17

• Higher the delivery of oxygen the greater the
  capillary PaO2
• The higher Phi for flow of oxygen to muscles

Question 18

PaCO2

Question 19

H+

Question 20

Feedback control of ventilation

Question 21

Feedforward control of ventilation

Question 22

Key characteristics of substrate use during exercise

Answer 22

• Increasing intensity increases carbohydrate
  (glycogen) metabolism
• Increasing duration increases fatty acid
  metabolism
• Training increases fatty acid metabolism at a
  given exercise intensity

Question 23

Increased intensity and increased carbohydrate metabolism

Answer 23

• Increasing exercise duration = increased reliance
  on fat metabolism
• Decreases reliance on carbohydrate metabolism

Question 24

Carbohydrate metabolism

Answer 24

• Within training, there is an increased reliance on
  fat
• There is a decreased reliance on carbohydrate
  metabolism during prolonged exercise

Question 25

Increased duration and training and increased fatty acid metabolism

Answer 25

- With training or extended exercise duration there is increased availability of fats - Increase inflow from fatty acid metabolism and aerobic ATP production