Week 4

Question 1

Chemoreceptors in Medulla will sense what?

Answer 1

PH change of CSF

Increase in PCO2

Question 2

Carotid Chemoreceptors are sensitive to changes in what?

Answer 2

Arterial PO2, PCO2 and PH

Question 3

Aortic Chemoreceptors are sensitive to changes in what?

Answer 3

Arterial PCO2 & PH

Question 4

What are muscle Metaboreceptors ?

Answer 4

Muscular Chemoreceptors

Question 5

What activates a Muscle Metaboreceptor to signal the respiratory system ?

Answer 5

Decreased muscular PH and increased extracellular K+

Question 6

At rest, what has the most influence on Pulmonary Ventilation?

Answer 6

Chemical state of blood (Humoral factors)

Question 7

In alveoli, what is considered critically low O2?

Answer 7

60mmHg

Question 8

What is the Hypothalamus’ role in in Ventilation ?

Answer 8

Controls the duration and intensity of the respiratory cycle

Question 9

What are the two main sub-divisions of regulating Pulmonary Ventilation at rest and during exercise ?

Answer 9

Cortical influence

Peripheral Influence

Question 10

At the onset of exercise, what happens to Ventilation

Answer 10

Rapid increase

Question 11

During exercise, when is the first plateau in RR?

Answer 11

After the onset of exercise, right before phase 2 occurs

Question 12

What occurs in phase 2 of exercise in regards to Ventilation rate ?

Answer 12

A second rise in Vent. Rate occurs

Question 13

During exercise, at which of the 3 stages does steady state occur

Answer 13

Third

Question 14

Define Ventilatory Threshold

Answer 14

the level at which energy demands can no longer be met by O2 alone

Question 15

Define Lactate Threshold

Answer 15

Point of increased Lactate accumulation

Question 16

What concentration of blood Lactate signifies OBLA has been reached ?

Answer 16

4 mM

Question 17

What are the four factors influencing OBLA

Answer 17

Muscle fibre type

Capillary density

Mitochondrial size and number

Enzyme concentrations

Question 18

What is the reaction by which the body removes H+ from the body through ventilation ?

Answer 18

CO2 + H2O H2CO3 H+ + HCO3

Question 19

List 4 Adaptations to Aerobic training

Answer 19

Type 1 fibre size and number increase

Increase capillary supply to each muscle fibre

Increased myoglobin content

Increase activity of oxidative enzymes

Question 20

Define O2 Deficit

Answer 20

Difference between total O2 consumption during exercise and O2 that would have been consumed had steady state consumption been achieved from the start

“ a lag in O2 uptake”