Homeostasis- Gas Concentration

Question 1

Oxygen

Answer 1

very low O2 levels influence breathing rate
nerves relay impulses to diaphragm and intercostals
very low O2 results in increase in breathing rate and depth

Question 2

Aortic and Carotid Bodies

Answer 2

sensitive to very low oxygen

Question 3

Carbon Dioxide

Answer 3

small changes in CO2 cause changes to breathing rates

increase in CO2 concentration also results in increase in H+ concentration

Question 4

Hydrogen Ion Concentration

Answer 4

as h+ increases, Ph decreases.
stimulates the aortic and carotid receptors which in turn transmit information to the respiratory centre in medulla
medulla increases breathing rate and depth

Question 5

Stretch Receptors

Answer 5

neurons located in lungs which are stimulated by stretching (inflation) of lungs
inflated= stretch receptors initiate impulse to medulla, which inhibits respiration
allows expiration to then occur, and prevents over=inflation of lungs

Question 6

what are the muscles involved with breathing?

Answer 6

intercostal muscles and diaphragm.

intercostal nerve and phrenic nerve

Question 7

where are the chemoreceptors for hydrogen ions located?

Answer 7

aortic and carotid bodies

Question 8

hyperventilation

Answer 8

rapid, deep breathing. It provides more oxygen than required and remove more CO2 than necessary.

Question 9

What effect does hyperventilation have on oxygen?

Answer 9

increases oxygen levels

Question 10

What effect does hyperventilation have on carbon dioxide?

Answer 10

decreases CO2 levels

Question 11

Why does hyperventilation before swimming under water can prove fatal?

Answer 11

it allows a person to stay under water for longer but not because of extra oxygen in the blood, its due to loss of CO2 (not enough CO2 to stimulate chemoreceptors). The breath-holding ability could be increased to such an extent that the individual loses consciousness from lack of O2 to the brain before feeling the urge to breathe.