Chapter 8.5 - Homeostasis Of Gas Concentration

Question 1

What stimulates the intercostal muscles?

Answer 1

Intercostal nerve

Question 2

What stimulates the diaphragm?

Answer 2

Phrenic nerve

Question 3

What happens if the nerves are insured?

Answer 3

Paralysis of the muscles that ventilate the lungs

Question 4

What controls the movement of intercostal muscles and diaphragm?

Answer 4

Impulses sent by the respiratory centre in the medulla

Question 5

What are the two regions in the respiratory centre?

Answer 5

• controls breathing in

- controls breathing out

Question 6

What is the formula for when carbon dioxide dissolves in the blood plasma?

Answer 6

Carbon dioxide + water carbonic acid H ion + bicarbonate ion

Question 7

What chemoreceptors detect low levels of oxygen?

Answer 7

Aortic and carotid bodies

Question 8

What stimulates the aortic and carotid bodies?

Answer 8

Increase in pH - immediate increase in rate and depth of breathing

Question 9

What is hyperventilation?

Answer 9

• rapid, deep breathing that provides more oxygen and removes more carbon dioxide than necessary

Question 10

Why do you need more oxygen when you exercise?

Answer 10

Because contracting muscles cells require large amounts of oxygen and produce large amounts of carbon dioxide

Question 11

How can breathing be controlled voluntarily?

Answer 11

• can occur due to connections from the cerebral cortex to descending tracts in the spinal cord
• bypasses the respiratory centre in medulla