Week 2

Question 1

What is Tidal Volume?

Answer 1

How much air is being inhaled in one breath. Never breath in full amount because of the body’s reserve.

Question 2

What is Vital Capacity?

Answer 2

How much the lung is truly able to ventilate in one breath.

Question 3

What is the total lung capacity and vital capacity (numbers)?

Answer 3

TLC = 6 litres
VC = 4.5L

Question 4

What is minute ventilation?

Answer 4

The volume of air breathed each minute.

Question 5

How do you calculate pulmonary ventilation?

Answer 5

V = tidal volume - breathing frequency.

Question 6

What is anatomical dead space and can it change?

Answer 6

ADS is the air you breath in but actually is not going to the alveoli and exchanging oxygen. It can change depending on the type of breathing. Ex) shallow breathing results in high minute ventilation but low alveolar ventilation.

Question 7

Why do we need scuba gear? Why can’t we just use a small snorkel?

Answer 7

If you have a narrow snorkel you will increase resistance due to the depth and hydrostatic pressure. There would be low flow and you would run out of capacity.

A wide snorkel decreases resistance but the increased radius will increase ADS leading to less oxygen getting to the body.

Question 8

Where is the respiratory control centre?

Answer 8

In the medulla oblongata.

Question 9

How does the respiratory centre prepare for the demands of exercise?

Answer 9

Having a prepared respiratory response is down to the motor cortex at the start of exercise and feedback from proprioceptors in the joints.

Question 10

Where are the central chemoreceptors and what do they do?

Answer 10

These receptors are in the brain - in the carotid bodies- and sense CO2 levels in the body through pH values.

Question 11

Where are the peripheral receptors? Why is this beneficial?

Answer 11

In the heart. Beneficial because all blood in the body must pass through the heart and the body gets feedback on the state of the body and its O2 and CO2 levels.

Question 12

Changes in PP CO2 (increase) cause what?

Answer 12

This is a signal for the body to breath. Increase ventilation.

Question 13

What method to deep divers do to delay the critical threshold of high CO2 forcing you to breath?

Answer 13

Shallow breathing- low CO2 in body = critical threshold is delayed.

Question 14

What is the physiological break point?

Answer 14

The transition between the easy going phase and the struggle phase.

Question 15

What is the struggle phase?

Answer 15

Voluntarily trying to control your breath.

Question 16

What does breath training emcompass?

Answer 16

Physiology of preparing the body and psychology to live through the discomfort and still think on your feet.

Question 17

What have wet suits done? What has the effect been on divers?

Answer 17

Protect the body from the cold? The adaptations such as larger vital capacity, inspiratory capacity and higher metabolic activity have gone away.

Question 18

Do breathing strips that a lot of athletes use, work?

Answer 18

No- air way dilator did not benefit performance or average power output.

Question 19

What is the central issue with COPD? What causes this?

Answer 19

Less oxygen to fuel daily activities. Caused by a combination of increased airway resistance, decreased capillary surface area, increased mucous build up, and decreased muscle mass and fatigue.

Question 20

What are the 3 disciplines of apnea diving?

Answer 20

• Maximal duration
• Distance
• Depth

Question 21

What does the body do when there is a reduction in oxygen uptake?

Answer 21

• Reducing heart rate and restricting blood flow to non-essential organs.

Question 22

What is a limiting factor to diving?

Answer 22

Equalisation of air filled cavities. Inner air and sinuses can rupture and damage. `

Question 23

What are some symptoms of decompression sickness?

Answer 23

• dizziness
• nausea
• lethargy
• abdominal pain
• skin pain
• joint pain