modifications to ventilation

Question 1

define apnea

Answer 1

cessation of breathing

can be a conscious decision, but eventually PCO_2 levels increase to a point that respiratory center overrides

Question 2

hyperventilation

Answer 2

faster than normal breathing

causes decrease in plasma CO_2 levels, peripheral vasodilation causes decrease in BP

Question 3

what is a major regulator of respiratory rate and depth?

Answer 3

CO_2, but indirectly through pH change

Question 4

when do bl O_2 levels affect respiration?

Answer 4

when levels decrease more than 50% from normal

Question 5

define hypercapnia?

Answer 5

too much CO_2

Question 6

define hypocapnia?

Answer 6

lower than normal CO_2

Question 7

what are chemoreceptors?

Answer 7

specialized neurons that respond to changes in chemical sol’n

Question 8

where are the central chemoreceptors? what do they connect to?

Answer 8

in medulla oblongata they are connected to the respiratory center

Question 9

how do the central chemoreceptors respond?

Answer 9

indirectly via changes to CO_2

Question 10

where are the peripheral chemoreceptors located? what do they connect to?

Answer 10

carotid and aortic bodies connected to resp center by cranial nerves IX and X

Question 11

how do the peripheral chemoreceptors respond?

Answer 11

directly to pH level

Question 12

carotid and aortic bodies respond to decreased PO_2 by

Answer 12

increasing stimulation of resp center to keep it active, despite falling O_2 levels

Question 13

define hypoxia?

Answer 13

decrease in O_2 levels below normal values