respiration 4

Question 1

Rhythmical breathing is controlled by ___________

Answer 1

skeletal muscles

Question 2

what does inspiration require?

Answer 2

inspiration requires action potentials in motor neurons

Question 3

expiration occurs due to what? (think muscles)

Answer 3

due to cessation of motor neuron activity and lung recoil

Question 4

rhythmic contraction of the breathing muscles is controlled by what?

Answer 4

controlled by pacemaker neurons

Question 5

how can the pacemaker neurons for respiration be modulated

Answer 5

• activity of pulmonary stretch receptors
• drugs
• partial pressures of respiratory gases and [H+]
• peripheral chemoreceptors being stimulated
• central chemoreceptors being stimulated

Question 6

what stimulates peripheral chemoreceptor for respiration?

Answer 6

stimulated by:

↑ [H+]

or ↓ PO2

Question 7

what stimulates central chemoreceptors for respiration?

Answer 7

↑ [H+] in extracellular fluid in brain

Question 8

ventilation rate increases below PO2 of about ____ mm Hg

Answer 8

60

Question 9

at PO2 = 60, Hb is ___% saturated

Answer 9

90%

Question 10

ventilation rate is much more sensitive to ______ than to PO2

Answer 10

PCO2

Question 11

rate increases above PCO2 of about _____ mm Hg

Answer 11

40

Question 12

anemia does not change ventilation….why not?

Answer 12

Hb content is reduced, but PO2 is normal

Question 13

carbon monoxide poisoning does not change ventilation…why not?

Answer 13

HbO2 is reduced, but PO2 is normal

Question 14

_____ poisoning symptoms depend on level of toxicity

Answer 14

CO2

Question 15

Ventilation rate can be modified by what non-respiratory sources of H+?

Answer 15

metabolic acidosis, e.g. excess lactic acid

metabolic alkalosis, e.g. severe vomiting

Question 16

T/F: during exercise, arterial O2 decreases, but not venous

Answer 16

FALSE

venous O2 decreases, but not arterial

Question 17

with severe exercise, arterial PCO2 will ________

Answer 17

decreases

Question 18

hypoxia is a deficiency of O2 at the ___________

Answer 18

tissue level

Question 19

________ hypoxia is caused by blood flow to tissues being too low

Answer 19

Ischemic

Question 20

what causes Histotoxic hypoxia?

Answer 20

cells being unable to utilize O2

Question 21

what are the causes of hypoxia?

Answer 21

1) Hypoventilation
2) Diffusion impairment
3) Shunt
4) Ventilation-perfusion inequality (COPD)

Question 22

what are the immediate effects of altitude hypoxia?

Answer 22

stimulate ventilation & increase anaerobic glycolysis

Question 23

what are the delayed responses for altitude hypoxia?

Answer 23

• increase RBC synthesis
• increase 2,3 DPG synthesis
• increase synthesis of other components of O2 delivery and consumption

Question 24

___________ is used by athletes to artificially increase RBC count

Answer 24

Erythropoietin

Question 25

_________ is a gene therapy that stimulates erythropoietin synthesis

Answer 25

Repoxygen