Ex phys exam 4 (copy)

As altitude increases, the partial pressure of inspired air (PIO2)

 

decreases

 

increases

 

does not change

decreases

As altitude increases, the percentage of oxygen in dry air

 

decreases

 

increases

 

does not change

does not change

As altitude increases, minute ventilation (VE)

 

decreases

 

increases

 

does not change

increases

As altitude increases, PCO2 of arterial blood (PaCO2)

 

decreases

 

increases

 

does not change

decreases

Which is most increased during submaximal aerobic exercise at high altitude compared to sea level

 

PIO2

 

PaCO2

 

stroke volume

 

a-v O2 difference

 

heart rate

heart rate

Acclimatization to high altitude includes all EXCEPT

 

blood hemoglobin concentration increases

 

possible increase in capillarization of skeletal muscle

 

increased mitochondrial density and mitochondrial enzymes in skeletal muscle

 

minute ventilation decreases so that it is the same as at sea level

minute ventilation decreases so that it is the same as at sea level

Performance is more impaired at altitude (e.g. about 2,000 meters) in aerobic events lasting

 

less than two minutes

 

20-30 minutes or longer

20-30 minutes or longer

When doing an aerobic workout at high altitude, absolute work intensity is __________ than it can be at sea level.

 

lower

 

higher

lower

Someone who wants to use a tent with adjustable air pressure to mimic living at high altitude would want ________ conditions.

 

hyperbaric

 

hypobaric

 

either

hypobaric

Which is greater?

 

metabolic heat production capacity (assuming a VO2 of 4 liters/min, each liter of O2 is equivalent to 5 kcal)

 

capacity for evaporative cooling (assuming maximal sweat rate of 30 ml/min, complete evaporation of the sweat, and a heat loss of 0.6 kcal/ml of sweat that’s evaporated)

 

they’re the same, that’s why core temperature never changes

metabolic heat production capacity (assuming a VO2 of 4 liters/min, each liter of O2 is equivalent to 5 kcal)

At low air temperatures (e.g. 40 degrees Fahrenheit), which is most important to body heat loss

 

convection

 

evaporation

 

radiation

convection

Convective cooling is least effective

 

when air temperature is equal to or greater than skin temperature

 

when swimming in water cooler than body temperature

 

when it’s windy

 

when the air temperature is low (e.g. 40-50 degrees Fahrenheit)

when air temperature is equal to or greater than skin temperature

Rise in core temperature during exercise is dependent on

 

whether or not a person is wearing heavy uniform, pads, and helmet

 

whether or not it’s sunny

 

work intensity

 

whether or not it’s humid

 

all of the above

all of the above

Sweat rate depends on

 

work rate

 

air temperature

 

body size

 

all of the above

all of the above

Fluid replacement during an aerobic event of a couple hours in duration under hot conditions

 

improves performance

 

impairs performance

improves performance

Heat acclimation does all EXCEPT

 

improves performance aerobic events (e.g. 60-90 min) under hot conditions

 

increases heart rate during aerobic events (e.g. 60-90 min) under hot conditions

 

increases plasma volume

 

increases sweating volume

 

causes sweating to start at a lower core temperature

increases heart rate during aerobic events (e.g. 60-90 min) under hot conditions

Which exercise causes the LEAST sweating (liters/hour)

 

swimming in water that’s 77 degrees Fahrenheit

 

American football in full gear, when it’s hot and sunny

 

tennis on a hot, sunny day

 

running a half marathon in hot, humid conditions

 

playing a soccer game on a hot, sunny day

swimming in water that’s 77 degrees Fahrenheit

During aerobic exercise under hot conditions, blood flow to the skin is ________ than under temperate conditions, so blood flow to skeletal muscle is _________ than under temperate conditions.

 

lower; lower

 

lower; higher

 

higher; lower

 

higher; higher

higher; lower

Which is greater?

 

maximal rate of sweating

 

maximal rate of rehydration

 

they’re always the same

maximal rate of sweating

Who sweats the most and at a lower core temperature during aerobic exercise?

 

untrained person

 

aerobically trained person

 

aerobically trained person who is heat acclimatized

 

sweat rate and core temperature for initiation of sweating are unaffected by training status

aerobically trained person who is heat acclimatized

Which is increased at high altitude compared to sea level?

 

PaCO₂ (arterial PCO₂)

 

Hemoglobin's saturation with oxygen

 

PaO₂ (arterial PaO₂)

 

PIO₂ (PO₂ of inspired air)

 

minute ventilation

minute ventilation

A person records her resting heart rate daily in St. Louis (about 150 m above sea level) and then compares it to her resting heart rate in Denver (about 1,600 m above seal level) when she takes a few days of vacation there. Her heart rate in Denver (compared to St. Louis) is:

 

higher

 

lower, because there's less oxygen to push around

 

about the same, because the oxygen percentage of the air in St. Louis and Denver is about the same

higher

If a person does aerobic exercise at the same absolute intensity (e.g. running velocity) at sea level and at high altitude, the percentage of VO₂max of this exercise is

 

higher at high altitude

 

lower at high altitude

 

not different between altitudes

higher at high altitude

Heat exchange from the body to the environment through convection is greatest when

 

the air is cool (e.g. 45 degrees Fahrenheit)

 

the air is a comfortable temperature (e.g. 72 degrees Fahrenheit)

 

the air is hot (e.g. 95 degrees Fahrenheit)

 

body cooling by convection is unaffected by air temperature

the air is cool (e.g. 45 degrees Fahrenheit)

The best strategy to factor altitude into aerobic training for maximal training effects is to

 

live high, train low

 

live and train at sea level

 

live at sea level and train at high altitude

 

live and train at high altitude

 

it doesn't matter where you live or train

live high, train low

On a day with low humidity, 85 degree Fahrenheit temperature, and bright sun, what is the primary means of heat exchange from the body to the environment during aerobic exercise (e.g. an hour run)?

 

heat lost in the breath

 

muscle contractions

 

evaporation of sweat

 

radiation

 

convection

evaporation of sweat

Who sweats most during aerobic exercise?

 

someone who is aerobically trained

 

someone who is not aerobically trained

 

someone who is aerobically trained and also heat acclimated

 

none of the above

someone who is aerobically trained and also heat acclimated

As core temperature rises, a primary cause of decreased oxygen delivery to working muscle is

 

greater blood flow to the skin

 

increased cardiac output

 

increased plasma volume

 

a decrease in tendency for oxygen to unload from hemoglobin as temperature rises

 

all of the above

greater blood flow to the skin

Which is most likely to be negatively affected by dehydration?

 

marathon running

 

weight lifting

 

sprint

 

high jump

 

long jump

marathon running

An aerobic event (e.g. endurance running) would be most negatively affected when it's hot with

 

low humidity

 

high humidity

 

both are equally bad

high humidity

A person wishing to mimic effects of living at high altitude would most likely use

 

a hypobaric chamber or tent

 

a hyperbaric chamber

 

either of the above would get the job done

a hypobaric chamber or tent

Under conditions of low humidity, evaporative heat loss is greater than dry heat loss at

 

10 degrees C

 

37 degrees C

 

evaporative heat loss is never greater than dry heat loss

 

evaporative heat loss is always greater than dry heat loss

37 degrees C

Which statement about water loss and fluid replacement is false?

 

The thirst mechanism always underestimates fluid loss during work in the heat and after work ends.

 

You should take frequent drinks throughout the work period.

 

If you drink 250 milliliters (about 1 cup) every 15 minutes, you can replace 1 liter per hour.

 

If, during prolonged periods of work in the heat, weight loss exceeds 2 percent, the person should rehydrate before returning to work or exercise.

 

Marathon runners are wise to drink as much as possible before the event and to drink as much as possible as frequently as possible during the event.

Marathon runners are wise to drink as much as possible before the event and to drink as much as possible as frequently as possible during the event.

Muscle can serve as temperature regulators by increasing body temp either through use or shivering.

 

True

 

False

True

Even when sweat does not evaporate and instead drips off the body, it provides a good cooling mechanism.

 

True

 

False

False

When a person first reaches a high altitude location, there is a stimulus for kidneys to produce more erythropoietin. Erythropoietin is a protein. What's the process for its increase at altitude

 

the portion of DNA corresponding to the erythropoietin gene is used as information for synthesis of a messenger RNA (mRNA) with the sequence information for erythropoietin

 

the erythropoietin mRNA contains the molecular information that guides the order of amino acids for ribosomes to attach together to make erythropoietin protein

 

both of the above

both of the above

What factors contribute to sweat rate?

 

air temperature

 

body size

 

level of fitness and heat acclimatization

 

exercise intensity

 

all of the above

all of the above

When is direct transfer of body heat from the skin to the air most effective?

 

when the air is cold

 

when the air is a comfortable room temperature

 

when the air is hot

when the air is cold

Compared to an untrained person, a trained and heat-acclimatized person has the following characteristics during a long, aerobic exercise session:

 

lower core temperature

 

starts sweating at a lower core temperature

 

sweats more

 

All of the above

All of the above

Sweating rate (before a person becomes dehydrated) depends on all EXCEPT

 

work rate

 

body size

 

air temperature

 

amount of insulating clothing or gear

 

rate of rehydration

rate of rehydration

A person records her rate of breathing when she's resting in St. Louis (about 150 m above sea level) and then compares it to her rate of breathing in Denver (about 1,600 m above seal level) when she takes a few days of vacation there. Her rate of breathing in Denver (compared to St. Louis) is:

 

higher

 

lower, because the air is less dense, making it easier to inhale

 

about the same, because resting metabolic rate doesn't change

higher

Heat exchange from the body to the environment through convection is greatest when

 

the air is cool (e.g. 45 degrees Fahrenheit)

 

the air is a comfortable temperature (e.g. 72 degrees Fahrenheit)

 

the air is hot (e.g. 95 degrees Fahrenheit)

 

body cooling by convection is unaffected by air temperature

the air is cool (e.g. 45 degrees Fahrenheit)

Which volume is greatest during an hour of exercise at 60% of VO₂max in hot, humid conditions?

 

sweat volume

 

water vapor lost in the breath

 

metabolic water

 

water released by glycogenolysis

 

all are more-or-less equal

sweat volume

An aerobic event (e.g. endurance running) would be most negatively affected when it's hot with

 

low humidity

 

high humidity

 

both are equally bad

high humidity

During prolonged aerobic exercise, blood flow to working muscle is __________ under cool conditions (e.g. 55 degrees Fahrenheit) than it is under hot, humid conditions. Assume that it's not cool enough to cause shivering.

 

greater

 

lower

 

the same

greater

As core temperature rises, a primary cause of decreased oxygen delivery to working muscle is

 

greater blood flow to the skin

 

increased cardiac output

 

increased plasma volume

 

a decrease in tendency for oxygen to unload from hemoglobin as temperature rises

 

all of the above

greater blood flow to the skin

Body cooling by evaporation of sweat is least effective

 

when it's windy

 

when humidity is low

 

when humidity is high

 

all of the above

when humidity is high

Under conditions of low humidity, evaporative heat loss is greater than dry heat loss at

 

10 degrees C

 

37 degrees C

 

evaporative heat loss is never greater than dry heat loss

 

evaporative heat loss is always greater than dry heat loss

37 degrees C

What is the main limiting factor for the rate of rehydration?

 

the rate fluid empties from the stomach

 

the rate of drinking

 

the taste and color of the beverage

the rate fluid empties from the stomach

if evap cooling is only means of body cooling (no transfer via air), can cooling keep pace w head prof for an effort of VO2 4 L/min

yes

no

no (Vo2 max=20 kcal/min, sweat is 18)

under what conditions would there be no heat transfer from body surface to the air

chilly cond

room temp

high temp

high temp

1. convective cooling is impaired by:

high temp

high humidity

2. evap cooling is impaired by:

high temp

high humidity

3. windy conditions enhance:

evap cooling

convective cooling

both

1. high temp

2. high humidity

3. both

A person’s height (stature) is greatest

 

on Earth

 

After a couple of months of microgravity

 

a day after return to Earth after spaceflight

After a couple of months of microgravity

Skinny-looking “bird legs” that show up within a day or two of microgravity are most likely due to

 

massive skeletal muscle atrophy in the legs

 

incredible bone loss

 

a shift of body fluid away from the lower body to the upper body

a shift of body fluid away from the lower body to the upper body

Which is a model to help understand the consequences of microgravity?

 

parabolic flight

 

head down bed rest

 

immobilization or wheelchair confinement

 

suspension of an animal’s hind limbs so they don’t bear weight

 

all of the above

all of the above

Long-term spaceflight appears to __________ stroke volume.

 

decrease

 

increase

 

have no affect on

decrease

What happens to VO2max during long-term space flight without adequate exercise countermeasures?

 

increases

 

decreases

 

does not change

decreases

Factors that could help explain a decline in VO2max during long-term exposure to microgravity are all EXCEPT

 

increased skeletal muscle mitochondria

 

decreased stroke volume

 

decreased plasma volume

 

decreased number of red blood cells

increased skeletal muscle mitochondria

During long term space flight, skeletal muscle strength

 

increases, because stature increases

 

decreases due to atrophy

 

is not affected, because fluid shifts into the skeletal muscles

decreases due to atrophy

During long-term space flight

 

bone loss occurs

 

there are gains in bone as stature increases

 

unloading of the bones allows greater bone mineral deposition

bone loss occurs

Every ~10 meters of depth underwater, pressure increases by about the equivalent of atmospheric pressure (atm, ~760 mm Hg).  Lung volume varies inversely with pressure.  At a depth of 10 meters, lung volume is

 

twice what it was at the surface

 

half of what it was at the surface

half of what it was at the surface

If a person breathes in pressurized air at depth, such that lung volume is the same as it would be at the surface, that person should

 

breath out air on the way to the surface to avoid lung overexpansion and injury

 

hold their breath to conserve oxygen when heading up to the surface

 

continue breathing pressurized air on the way to the surface

breath out air on the way to the surface to avoid lung overexpansion and injury

Breath holding limit is determined by

 

alveolar PO2

 

arterial PCO2

 

both

arterial PCO2

A diver can increase dive time by these strategies EXCEPT

 

swimming vigorously to increase PvCO2

 

hyperventilating before the dive to decrease PaCO2

 

keeping activity to a minimum to avoid CO2 production

swimming vigorously to increase PvCO2

The mammalian diving response includes all EXCEPT

 

bradycardia

 

decreased cardiac output

 

peripheral vasocontriction

 

lactate accumulation in underperfused skeletal muscle

 

increased heart rate

increased heart rate

Why can’t a person hang out on the bottom of a 10-foot deep pool by using a snorkel that reaches to the surface?

 

at that depth, the diaphragm could not overcome the high pressure, so breathing could not occur

 

even if breathing could occur, the dead space would be so large that little or no fresh air could make it into the alveoli

 

both

both

A chamber used to gradually decrease pressure and thus avoid formation of nitrogen bubbles should be

 

hypobaric

 

hyperbaric

 

both

hyperbaric

Why can’t a person hang out on the bottom of a 10-foot deep pool by using a snorkel that reaches to the surface?

 

at that depth, the diaphragm could not overcome the high pressure, so breathing could not occur

 

even if breathing could occur, the dead space would be so large that little or no fresh air could make it into the alveoli

 

both

both

Which anatomy at the knee yields the lowest loading pressures per unit surface loading area, assuming that the body mass above the knee is the same for all three organisms?

 

A

 

B

 

C

 

load per unit area is the same in all

B

Elite distance runners generally swing their legs with their knees bent, so the heel passes close under the hips. What does this do?

 

decreases moment of inertia of the swinging leg

 

decreases the mass of the swinging leg

 

decreases the loading stress

 

decreases foot mass

 

increases oxygen cost of transport

decreases moment of inertia of the swinging leg

Hyperventilation results in

 

increased PaCO₂

 

decreased PaCO₂

 

no change in PaCO₂

decreased PaCO₂

The mammalian diving response includes all EXCEPT

 

bradycardia

 

decreased cardiac output

 

peripheral vasoconstriction

 

lactate accumulation in underperfused skeletal muscle

 

increased heart rate

increased heart rate

Breath holding limit is determined by

 

alveolar PO2

 

arterial PCO2

 

both

arterial PCO2

Given the model you have seen regarding elastic recoil in human running, elastic energy storage mediated by the achilles tendon is

 

increased when the foot is more dorsiflexed at footstrike

 

increased when the foot is more plantarflexed at footstrike

 

not affected by ankle angle

increased when the foot is more plantarflexed at footstrike

It has been suggested that barefoot running increases running economy. If that is the case, what factors would be likely to be contributors (in comparison to running while wearing shoes)?

 

decrease in distal mass

 

increase in elastic recoil

 

increased loading surface

 

all of the above

 

A and B

A and B

Upon return to the surface after a dive to 50 meters, who would be best served by exhaling air on the way up?

 

a free-diver who takes a breath before diving and holds it on the way down

 

someone who's breathing compressed air

 

someone diving with a snorkel

 

all of the above

someone who's breathing compressed air

Which can increase the length of an underwater free dive?

 

hyperventilation before diving

 

breathing pure oxygen before diving

 

vigorous physical activity during the dive

 

holding the breath for a minute before the dive to get used to it

 

deliberately decreasing minute ventilation in the few minutes before the dive

hyperventilation before diving

All are models to help understand microgravity EXCEPT

 

hypobaric/hypoxic tent

 

parabolic flight

 

head down bed rest

 

wheelchair confinement

 

suspension of a rodent's hind limbs to prevent weightbearin

hypobaric/hypoxic tent

Which contributes to lower moment of inertia around the hip and knee during running?

 

large gluteus maximus

 

narrow hips and wide shoulders

 

decreased mass and length of feet and toes

 

tall and narrow form

decreased mass and length of feet and toes

Absorption of CO₂ during a dive assisted by a breathing device is essential in a

 

closed-circuit system

 

open-circuit system

 

both of the above

closed-circuit system

In spring, 2019, scientists were able to attach a heart monitor to a blue whale and measure its heart rate during a dive. If its heart rate at the surface was 23 beats per minute, and its heart rate responded as might be expected from the mammalian diving response, its heart rate at great depth was most likely

 

its maximal heart rate

 

2 beats per minute

 

37 beats per minute

 

heart rate corresponding to lactate threshold

 

zero, because the entire dive is supported by anaerobic ATP production

2 beats per minute

The mammalian diving response includes all EXCEPT

 

bradycardia

 

decreased cardiac output

 

peripheral vasocontriction

 

lactate accumulation in underperfused skeletal muscle

 

increased heart rate

increased heart rate

A chamber used to gradually decrease pressure and thus avoid formation of nitrogen bubbles should be

 

hypobaric

 

hyperbaric

 

both

hyperbaric

Under which condition would moment of inertia of the lower leg and foot around the knee be higher?

 

barefoot condition

 

shod condition

 

neither

shod condition

For humans, the curve describing oxygen cost of transport at various walking speeds is

 

U-shaped

 

linear

 

an inverted U

 

an inverted pendulum

 

largely dependent on elastic recoil

U-shaped

Under which condition would moment of inertia of the lower leg and foot around the knee be LOWER?

 

barefoot condition

 

shod condition

 

neither

barefoot condition

Which type of exercise allows the greatest energy expenditure over a 20 minute period?

 

lifting heavy (1-8RM) weights

 

aerobic exercise at the maximum intensity that can be sustained for 20 min

 

sprinting

 

a sport with repeated high-intensity work interspersed with rest, like American football

 

lifting relatively light weights (15RM)

aerobic exercise at the maximum intensity that can be sustained for 20 min

Which would contribute to lower loading stresses (kg/cm² loading surface) during running?

 

wide hips

 

long snout

 

large hands

 

nuchal ligament

 

large calcaneal tuber

large calcaneal tuber

Early in space flight

 

there's a big increase in body fluid volume

 

body fluid distribution shifts toward the upper body

 

fluid retention in the legs is a big problem

 

cardiac output increases to compensate for loss of body water

body fluid distribution shifts toward the upper body

A person who wants to prevent formation of nitrogen bubbles after a long dive at great depth would be more likely to use

 

a hyperbaric chamber

 

a hypobaric chamber

 

either of the above would work

a hyperbaric chamber

Which contributes to lower moment of inertia around the hip and knee during running?

 

large gluteus maximus

 

narrow hips and wide shoulders

 

decreased mass and length of feet and toes

 

tall and narrow form

decreased mass and length of feet and toes

Assuming that these skulls are in intact animals, which skull requires the most muscle tension to maintain the position shown on the vertebral columns?

 

A

 

B

 

C

 

no muscle force is required for any of these because of presence of the nuchal ligament

 

A and C, because of greater cranial circulation

A

Every ~10 meters of depth underwater, pressure increases by about the equivalent of atmospheric pressure (atm, ~760 mm Hg).  Lung volume varies inversely with pressure.  At a depth of 10 meters, lung volume is

 

twice what it was at the surface

 

half of what it was at the surface

half of what it was at the surface

If a person breathes in pressurized air at depth, such that lung volume is the same as it would be at the surface, that person should

 

breath out air on the way to the surface to avoid lung overexpansion and injury

 

hold their breath to conserve oxygen when heading up to the surface

 

continue breathing pressurized air on the way to the surface

breath out air on the way to the surface to avoid lung overexpansion and injury

do we sweat more or less or equal to the amount expended?—>in terms of replenishing sweat stores

more— 1 L/hr replenish to 2 L/h off

heat acclim inc or dec:

sweat volume

urinary loss

salt conc in sweat

blood volume

sweat volume inc

urinary loss dec

salt conc in sweat dec

blood volume inc

who would be more in danger of hypoxia (bc drop in PO2 as lung volume inc) in return to surface after a deep dive?

free diver

scuba diver

free diver bc PO2 was diluted when dove

after a whale does a long dive that leads to muscle lactate accum, what happens to blood lactate when blood flow to muscle resumes (out of muscle)?

increases

decreases

increases

what sort of countermeasures would be best to slow the decline in VO2max in prolonged space flight

rez training

aerobic training

plyometrics

aerobic training

bonel loss in spaceflight would be least in

spine

femurs

pelvis

arms

arms