Test 3: Wk 11: 9 High Altitude, Exercise, and Deep Sea Adaptations - Puri

Question 1

Owles Point represents

Answer 1

ventilation increase above the predicted by an extrapolation of the linear part of the ventilation/ oxygen consumption relationship

Question 2

Anaerobic Threshold

Answer 2

point where alveolar ventilation increase is disproportionate to O2 consumption

Question 3

any increase in O2 consumption beyond owles point leads to

Answer 3

greater increase in alveolar ventilation that what is required

Question 4

disproportionate — occurs after the anaerobic threshold

Answer 4

hyperventialtion

Question 5

PaCO2 =

Answer 5

PaCO2 = VCO2 / VA

Question 6

before anaerobic threshold is reached, VA increases proportional to

Answer 6

VCO2

Question 7

at normal work loads PaCO2, PaO2 and pH are — than anaerobic threshold

Answer 7

less than

Question 8

Exercise Hyperpnea

Answer 8

not hyperventilation, metabolic rate has increased and so has ventilation

Question 9

— most likely drives surplus alveolar ventilation during exercise

Answer 9

lactic acid

Question 10

lactate — and blood pH — once anaerobic threshold is met

Answer 10

incerase; decrease

Question 11

metabolic acidosis stimulates

Answer 11

peripheral chemoreceptors to increase ventilation

Question 12

inspiration increase disproportionately greater than

Answer 12

CO2 production

Question 13

PaCO2 — and PaO2 — at high workloads due to alveolar ventilation

Answer 13

decreases; increases

Question 14

Anaerobic threshold

Answer 14

point where alveolar ventilation increase is disproportionate to O2 consumption

Question 15

any increase in O2 consumption beyond Owles point leads to

Answer 15

greater increase in alveolar ventilation that what is required

Question 16

Surplus alveolar ventilation is most likely driven by

Answer 16

lactic acid

Question 17

PaCO2 =

Answer 17

PaCO2 = VCO2 / VA

Question 18

before Anaerobic threshold is reached

Answer 18

VA increases proportional to VCO2

Question 19

at normal workloads PaCO2, PaPO2, and pH are — than anaerobic threshold

Answer 19

less than

Question 20

Exercise Hyperpnea

Answer 20

not hyperventilation

metabolic rate has increased and so has ventilation

Question 21

lactate — and blood pH — once anaerobic threshold is met

Answer 21

metabolic acidosis stimulates

Question 22

metabolic acidosis stimulates

Answer 22

peripheral chemoreceptors to increase ventilation

Question 23

ventilation increases disproportionately greater than

Answer 23

CO2 production

Question 24

PaCO2 — and PaO2 — at high workloads due to alveolar ventilation

Answer 24

decreases; increases

Question 25

— will not be effected until ventilation changes

Answer 25

PaCO2

Question 26

Impaired mental function from hypoxia is due to

Answer 26

direct effect of hypoxia on brain tissue and from cerebral vasoconstriction from hypocapnia

Question 27

cerebral vasoconstriction is causes by

Answer 27

hypocapnia

Question 28

Acute exposure altitude sickness 5km sx

Answer 28

amnesia, dizziness, breathless at rest, insomnia, anorexia

Question 29

Acute exposure altitude sickness 10km sx

Answer 29

loss of consciousness

Question 30

Acute exposure altitude sickness ~20km sx

Answer 30

body fluids boil

Question 31

why does hyperventilation occur during acclimation to high altitude

Answer 31

increased sensitivity of peripheral chemoreceptors

Question 32

PAO2 =

Answer 32

PAO2 = PIO2 - PACO2

Question 33

PIO2 at high altitudes

Answer 33

decreases

Question 34

Hypercapnia

Answer 34

higher than normal PaCO@ >45

Question 35

Hypocapnia

Answer 35

lower than normal PaCO2 <40

Question 36

Hypocapnia can result only from an alveolar ventilation that is

Answer 36

excessive in relation

to carbon dioxide production

Question 37

— is a common cause of hypocapnia

Answer 37

Hypoxemia

Question 38

Hypoxemia occurs in

Answer 38

congenital heart disease

with right- to-left shunting, residence at high altitude, Po2 below about 60mmHg.

Question 39

Hypocapnia secondary to hypoxaemia opposes the

Answer 39

ventilatory response to the

hypoxemia.

Question 40

Metabolic acidosis produces a compensatory

Answer 40

hyperventilation

Question 41

Neurological disorders may result in — and —

Answer 41

hyperventilation and hypocapnia

Question 42

Hypercapnia is most commonly caused by

Answer 42

ventilatory failure due to acute or chronic conditions

Question 43

ARDS is an example of

Answer 43

acute ventilatory failure

Question 44

COPD is an example of

Answer 44

chronic ventilatory failure

Question 45

every 10m of seawater is — atm

Answer 45

1 additional atm

Question 46

10m below surface of sea atm =

Answer 46

2 atm

Question 47

N2 is highly lipid soluble and

high N2 interferes with

Answer 47

ion channels and slows ion conductance

Question 48

Mild nitrogen narcosis resembles

Answer 48

alcohol

intoxication

Question 49

“Martini’s law”

Answer 49

each 15 m of depth has the effects of drinking an additional martini.

Question 50

Solution to nitrogen necrosis in scuba diving

Answer 50

replace nitrogen with helium in the SCUBA tanks. Helium is more inert than
nitrogen and has less side effects.

Question 51

Mild oxygen toxicity

Answer 51

disorientation and headaches

Question 52

Severe oxygen toxicity

Answer 52

damage to the airways, pulmonary edema, coma, and death.

Question 53

solution to oxygen toxicity in scuba diving

Answer 53

scuba tank mixture is typically 98% helium and inly 2% oxygen. This is enough
to achieve PaO2 similar to sea levels due to high barometric pressures

Question 54

Decompression sickness (DCS or bends) is caused by

Answer 54

local bubble formation,

either in tissues or in venous blood

Question 55

DCS Bubbles in veins cause

Answer 55

obstruction, leading to capillary leaks

Question 56

Mild or type I DCS

Answer 56

mild pains (“niggles”), pruritus, a skin rash, and deep throbbing pain (bends),

Question 57

Serious or type II DCS

Answer 57

CNS, lungs, and circulatory system.

Question 58

CNS disorder in dysbarism

Answer 58

most commonly involving the spinal cord—reflects bubble formation in the myelin sheath of axons, which compromises nerve conduction

dizziness—the staggers—to paralysis.

Question 59

Pulmonary symptoms in dysbarism

Answer 59

the chokes—
result from bubbles that originate in the systemic veins and travel as gas emboli to
lodge in the pulmonary circulation, and include burning pain on inspiration

Question 60

circulatory system dysbarism

Answer 60

bubbles not only can
obstruct blood flow but also can trigger the coagulation cascade, leading to the
release of vasoactive substance

Question 61

Arterial gas embolization (AGE) is caused by

Answer 61

bubbles that enter the systemic arterial blood via either tears in the alveoli or right-to-left shunts and then become wedged in the brain or other organs.

Question 62

Best treatment of dysbarism is

Answer 62

recompression