Jackson 4

Question 1

Rhythmical breathing is controlled by

Answer 1

skeletal muscles

Question 2

inspiration requires action potentials in

Answer 2

motor neurons

Question 3

expiration due to cessation of

Answer 3

motor neuron activity and lung recoil

Question 4

rhythmic contraction controlled by

Answer 4

pacemaker neurons

Question 5

Role of medulla oblongata and pacemaker cells

Activity of pacemaker neurons can be modulated by…

Answer 5

activity of pulmonary stretch receptors
drugs, e.g. barbiturates and opiates/morphine
partial pressures of respiratory gases and [H+]

Question 6

↓ PO2 —->

Answer 6

↑ ventilation rate

Question 7

↑ PCO2 or [H+] –>

Answer 7

↑ ventilation rate

Question 8

regulation of ventilation rate by respiratory gases and [H+] involves

Answer 8

chemoreceptors in two locations

Question 9

peripheral chemoreceptors are stimulated by

Answer 9

↑ [H+] or ↓ PO2

Question 10

central chemoreceptors are stimulated by

Answer 10

↑ [H+] in extracellular fluid in brain

Question 11

Ventilation rate can be modulated by

Answer 11

peripheral chemoreceptors responding to a change in PO2

Question 12

ventilation rate increases below PO2 of about

Answer 12

60 mm Hg

Question 13

note that at PO2 = 60, Hb is ———-, so ventilation rate begins to increase before blood is depleted of O2

Answer 13

90% saturated

Question 14

Ventilation also can be modulated by

Answer 14

peripheral & central chemoreceptors responding to a change in PCO2 and [H+]

Question 15

ventilation rate is much more sensitive to

Answer 15

PCO2 than to PO2

Question 16

rate increases above PCO2 of about

Answer 16

40 mm Hg

Question 17

central chemoreceptor response to decrease in brain pH is

Answer 17

primary regulator

Question 18

CO2 poisoning symptoms depend on ———- – can lead to death

Answer 18

level of toxicity

Question 19

Ventilation rate can be modified by

Answer 19

non-respiratory sources of H+

Question 20

metabolic acidosis, e.g.

Answer 20

excess lactic acid

Question 21

metabolic alkalosis, e.g.

Answer 21

severe vomiting

Question 22

Note that anemia does not

Answer 22

change ventilation

Question 23

, carbon monoxide poisoning does not

Answer 23

change ventilation

Question 24

During exercise, alveolar ventilation can increase

Answer 24

20 fold, but mechanism underlying the increase is not completely understood.

Question 25

arterial PCO2 ————- until exercise becomes strenuous; venous PCO2 ———-

Answer 25

typically unchanged

increases but no change in arterial values

Question 26

ventilation increases in exact proportion to

Answer 26

CO2 production and with severe exercise, arterial PCO2 actually decreases due to hyperventilation

Question 27

decreased PO2?

Answer 27

as with CO2, venous O2 decreases, but not arterial

increase in ventilation is proportional to O2 use

Question 28

increased H+?

requires

Answer 28

intense exercise for this to be a factor due to lactic acid accumulation
Conclusion: multiple factors provide input to the respiratory center and contribute to increasing ventilation during exercise

Question 29

Hypoxia =

Answer 29

a deficiency of O2 at the level of the tissues

Question 30

old school - RBC packing or use

Answer 30

recombinant human EPO

Question 31

modern option – use gene therapy to increase

Answer 31

endogenous EPO

Question 32

Can also train at high altitude to stimulate

Answer 32

EPO production in response to low arterial PO2.

Question 33

high altitude training effect: can be accomplished at sea level by

Answer 33

sleeping in a hypobaric atmosphere

Question 34

training at low / normal altitude conditions body to utilize

Answer 34

increased O2 availability

Question 35

Physiological principles in sports

How can physiological principles be applied to increase the

Answer 35

O2 carrying capacity of the blood in order to enhance athletic performance?

Question 36

hypoxic hypoxia or hypoxemia -

Answer 36

decreased arterial PO2

Question 37

anemic hypoxia –

Answer 37

normal arterial PO2; decreased hemoglobin and O2 content of blood

Question 38

ischemic hypoxia–

Answer 38

blood flow to tissues is too low

Question 39

histotoxic hypoxia -

Answer 39

cells unable to utilize O2

Question 40

Hypoxic hypoxia can be caused by a number of conditions

Answer 40

hypoventilation –
diffusion impairment –
vascular shunt

ventilation-perfusion inequality

Question 41

hypoventilation

Answer 41

increases arterial PCO2

diffusion impairment – thickened alveoli-blood interface

vascular shunt – blood bypasses alveoli

ventilation-perfusion inequality – can occur as a consequence of COPD

Question 42

diffusion impairment –

Answer 42

thickened alveoli-blood interface

Question 43

vascular shunt –

Answer 43

blood bypasses alveoli

Question 44

ventilation-perfusion inequality –

Answer 44

can occur as a consequence of COPD

Question 45

Because Patm decreases as altitude increases, PO2

Answer 45

also decreases (even though O2 still 21%)

Question 46

Immediate responses T

Answer 46

stimulate ventilation –

increased dependence on anaerobic glycolysis –

Question 47

Acclimatization to high altitude depends on delayed responses that take days or weeks

Answer 47

increased erythropoiesis which results in polycytothemia; stimulated by erythropoietin (EPO), a hormone from the kidney

increased 2,3 DPG synthesis which will shift the Hb-O2 curve to the right

increased synthesis of other components of O2 delivery and consumption

also change:
capillary density –

mitochondria –

myoglobin -