Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Exercise Physiology > Final Exam > Flashcards

Final Exam Flashcards

1
Q

thermal balance

A

Core temperature represents a dynamic equilibrium between factors that add and subtract body heat

Integration of mechanisms that alter heat transfer to periphery regulates evaporative cooling and varies heat production to sustain thermal balance​

Core temperature rises if heat gain exceeds heat loss (i.e., during vigorous exercise in warm, humid environment)​

Core temperature declines in cold when heat loss exceeds heat production​

37 degrees Celsius, 98.6 degrees Fahrenheit ​

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how is thermal balance controlled and how can exercise alter you ability to control body heat?

A

Primarily controlled during exercise through sweat, losing the ability to sweat is losing the ability to control our thermal balance​

Trained individual can adapt to heat better due to an increase in plasma volume (allows sweating)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

hyperthermia (heat stress)

A

an increase in deep internal body temperature above normal

heat stress challenges body to dissipate excess heat from working muscles during exercises

75% of energy from food is released as heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

thermoregulation (heat stress)

A

ability of body to maintain constant internal temperature

human body’s ability to maintain constant body temperature makes us homeotherms - able to perform in extreme environments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how does elevated heat/humidity affect body cooling?

A

increases challenge by blocking heat dissipation from body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

thermoregulation

A

receptors in periphery & CNS detect temperature changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

periphery

A

receptors in & under skin, in peritoneal (abdominal) cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

CNS receptors in:

A

brain stem

spinal cord

hypothalamus: acts like thermostat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

hypothalamic control

A

hypothalamus contains coordinating center for temperature regulation

cannot turn of heat; initiates responses to protect from buildup or loss of heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

activation of heat-regulating mechanisms:

A

thermal receptors in skin provide input to central control center

changes in temperature of blood that perfuses hypothalamus directly stimulate this area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

circulation

A

at rest in heat, heart rate and cardiac output increase while superficial arterial and venous blood vessels dilate to divert warm blood to body shell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

evaporation

A

effective thermal defense exists when evaporative cooling combines with large cutaneous blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

hormonal adjustments

A

sweating produces loss of water and electrolytes, initiating hormonal adjustments to conserve salts and fluids (increased aldosterone and anti-diuretic hormone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

fluid loss

A

Evaporative cooling dissipates heat in exercise, placing a demand on fluid reserves, often producing hypohydration​

Excessive sweating leads to serious fluid loss and reduced plasma volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Competitive cardiovascular demands of exercise in heat:

A

Muscles require oxygen to sustain energy metabolism​

Arterial blood that divert

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

as we dehydrate…

A

As we dehydrate, blood thickens.​

Heart works harder, blood loses liquid portion and becomes thicker. Cannot deliver the oxygen to skeletal muscle.​

Stroke Volume increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

cardiovascular drift

A

refers to increase in heart rate that occurs during prolonged endurance exercise with little or no change in workload

increase in heart rate due to dehydration without an increase in intensity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

consequences of dehydration

A

Modest fluid loss of 2% body mass adversely affects exercise performance (40-50 minutes in warm environment)​

Augmented hyperthermia​

Increased cardiovascular strain​

Altered metabolic and central nervous system functions​

Increased perception of effort

As dehydration progresses and plasma volume decreases, peripheral blood flow and sweating rate diminish, making thermoregulation progressively more difficult​

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

exercise in heat

A

submaximal exercise produces lower SV, causing higher HR at all submaximal levels

higher HR in maximal exercise does not offset SV decrease, so maximal cardiac output decreases

maintaining cutaneous and muscle blood flow requires other tissues to compromise blood supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

hyperhydration

A

ingesting “extra” water before exercising in the heat offers thermoregulatory protection

in reality, would have to urinate more often.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

convection (mechanisms of heat loss)

A

air blows over surface of skin (or running water as with swimming)

fluid medium to cool

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

conduction (mechanisms of heat loss)

A

physical contact between 2 surfaces, such as sitting in a cold-water bath to treat heat stroke

gaining heat (or cool) from hot (or cool) surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

radiation

A

molecules in motion emit electromagnetic waves such as the sun

worse at altitude

only 4% of heat loss from radiation in hot environments (vs. 67% at normal temp)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

evaporation

A

sweat on skin vaporizes, taking heat with it. Risk of dehydration

convection and evaporation work together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Three factors influence total amount of sweat vaporized from skin and/or pulmonary surfaces:​

A

Surface exposed to environment​

Temperature and relative humidity of ambient air​

Convective air currents about the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Relative Humidity…

A

most important factor determining effectiveness of evaporative heat loss

ratio of water in ambient air to total quantity of moisture that air could contain

in humid environment, less convection and evaporation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

countermeasures (clothing)

A

Physiologic adaptations can only protect an individual to a certain degree​

Designed to protect against environmental stressors​

Technological advances for both cooling and keeping you warm in microclimates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

circulatory and metabolic responses to heat stress

A

Heat increases heart rate & cardiac output (sub-maximal activity, decreased at maximal exercise)​

Redirects circulatory flow to periphery to:​

Dissipate heat​

Cool blood​

Reddens skin​

Flushes complexion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

body composition (influence of body composition and physical fitness level)

A

Larger body mass = greater heat production​

Ratio of body volume (generate heat): body surface area (dissipate heat) less favourable in some NFL players​

Body fat insulates, makes heat loss more difficult​

Adipose tissue decreases ability to dissipate heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

fitness level (influence of body composition and physical fitness level)

A

Hot environments require redistribution of blood from core and muscle to periphery to dissipate heat​

Greater fitness = greater cardiac output​

Greater cardiac output = improved ability to redistribute blood from muscle and dissipate heat​

Age:​

More body fat​

Decreased ability to tolerate and dissipate heat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

korey stringer

A

core temp reached 108 degrees

died from heat stroke

brain turned to “mush”

32
Q

heat cramps

A

muscle cramps that occur when one is exposed to heat

triggered by intense exercise

characterized by painful, involuntary muscle contractions

33
Q

heat cramps result from

A

dehydration - lose plasma volume & sodium

electrolyte imbalance, specifically whole-body sodium deficit

neuromuscular fatigue

34
Q

syncope

A

fainting or “passing out”

often occurs when sitting or standing or after an activity in heat, dizziness or lightheadedness may occur beforehand

more common when individuals have not be acclimated or acclimatized

need adequate cool down

35
Q

syncope is caused by:

A

Excessive peripheral dilation​

Pooling of blood in legs, reducing venous return​

Dehydration​

Reduction in cardiac output​

Brain ischemia

36
Q

heat exhaustion

A

typically occurs in hot & humid environments

confused with exertional heat stroke

fluid loss decreases SV, decreasing cardiac output

37
Q

heat exhaustion is caused by:

A

heavy sweating

dehydration

sodium loss

energy depletion

38
Q

exertional heat stroke (EHS)

A

medical emergency: can lead to death if not treated quickly (temp above 109)

body loses its ability to cool itself

failure to dissipate heat after intense exercise

termoregulatory center is overwhelmed, leading to stroke

core temp above 104 degrees

39
Q

exertional heat stroke treatment

A

rapid cooling of body

ice bath, cold compress

cool blood where major arteries are (head, neck, armpits, groin area, back of knees)

40
Q

complications of exertional heat stroke

A

Lactic acidosis​

Acute renal failure​

Rhabdomyolysis (destruction of muscle tissue releasing proteins into blood)​

Bleeding disorders​

Death​

Treatment: immediate, rapid cooling preferably in ice water bath; monitor temperature with rectal thermometer

41
Q

fitness level (factors affecting heat illness)

A

Greater fitness = less susceptibility to heat illness​

Carefully consider fitness before engaging in activity in heat​

Cardiovascular fitness should be primary focus of conditioning

42
Q

age (factors affecting heat illness)

A

Cardiovascular function declines with age​

Decline in cardiac output with age reduces tolerance to heat​

Heat acclimatization is possible

43
Q

endurance performance in the heat

A

as heat increases, performance declines

44
Q

measures to ensure optimal performance

A

Prior acclimatization (go to where you’re going to be competing) or acclimation (use to environment you’ll be competing in through artificial means) ​

Proper hydration​

Physical conditioning (actual temperature, relative humidity, cloud coverage, and non/prevelance of wind)

45
Q

wet-bulb globe temperature (WGBT)

A

a composite temperature used to estimate the effect of temperature, humidity, and solar radiation on humans

46
Q

depends on duration of event & duration of heat exposure (anaerobic & strength performance in the heat)

A

Limited exposure in shorter activities may not affect performance at all (100-m track)​

Longer events are more likely to affect performance (1500-m track) and predispose to heat illness​

Hypohydration does reduce strength, power, and muscular endurance

47
Q

anaerobic & strength performance in the heat improved by:

A

cooling methods

hydration

limiting of exposure to heat

48
Q

acclimation

A

physiological adaptation to an artificial environment

49
Q

acclimatization

A

physiological adaptation to a natural environment

takes bout 2 wks to adapt to altitudes up to 2300 m (7500 ft); after, each 610-m increase requires 1 extra wk

adaptions dissipate within 2-3 wks after returning to sea level

50
Q

time course of adaptations: cardiovascular system

A

1-5 days (plasma volume, reduced heart rate at workload, improved blood flow)

51
Q

time course of adaptations: temperature regulation

A

5-8 days (sweat rate, sweat at lower temperatures, sweat gland adaptations)

52
Q

time course of adaptations: conservation of sodium chloride

A

3-9 days (losses from urine and sweat decrease)

53
Q

time course of adaptations: all adaptations

A

up to 14 days (increased heat loss, decreased core & skin temp, decrease VO2 at workload, improved exercise economy)​

Adaptations lost after 2.5 to 5 weeks out of heat

54
Q

cold receptors in body

A

Monitor change & rate of decrease in temperature​

Signal many different actions to occur​

Are fewer in number than heat receptors​

Are found in the skin, abdominal viscera, & spinal cord

55
Q

bodys defense against cold

A

Vasoconstriction of blood vessels in skin​

Decrease sweating​

Release thyroid hormones to increase metabolism and heat production​

Shivering of skeletal muscle​

Epinephrine: increase metabolism; norepinephrine: increase vasoconstriction​

Hair stands up to increase insulation (less effective in humans)​

Decreased blood flow to skeletal muscle (unless physical activity increases)​

Curling up to preserve core heat, seeking shelter, finding heat sources, eating, putting on additional clothing

56
Q

hypothermia

A

decrease in bodys temperature to a point that normal physiological function is impaired

57
Q

hypothermia stage 1

A

body temp 1 to 2°C below normal​

Loss in ability to perform complex motor tasks​

Breathing becomes rapid & shallow

58
Q

hypothermia stage 2

A

body temp 2 to 4°C below normal​

Neuromuscular function is affected

59
Q

hypothermia stage 3

A

body temp below 32°C​

Body systems shut down, organs fail, brain dies

60
Q

afterdrop

A

the continued fall of deep body temperatures during rewarming after hypothermia

61
Q

performance responses to cold

A

Reductions in neuromuscular activity​

Reduction in nerve conduction velocity, or rate that neural impulses travel to muscle fiber

Reduction in force production (except possibly eccentric actions, but only with mild cooling)​

Diminished power output​

Decreased heart rate at given workload​

Decreased time to peak power

62
Q

physiological adaptations of acclimatization/acclimation

A

vasodilation in response to high altitude cold exposure

higher basal metabolic rates (Eskimos)

63
Q

barometric pressure (Pb)

A

760 mmHg at sea level

64
Q

partial pressure of oxygen (PO2)

A

portion of Pb exerted by oxygen

0.2093 x Pb ~ 159 mmHg at sea level

reduced PO2 at altitude limits exercise performance

65
Q

hypobaria

A

reduced Pb seen at altitude

results in hypoxia (partial pressure of O2 is reduced)

66
Q

stress of altitude

A

Altitude’s physiologic challenge comes directly ​
from decreased ambient Po2​

O2 transport cascade refers to progressive changes in environment’s O2 pressure and bo

67
Q

other challenges with altitude

A

Increased cold with increased altitude​

Dehydration induced by cold (which has lower water vapor than warm air, increases loss of water - particularly when paired with physical exertion)​

Increased solar radiation (decreased distance and thinner atmosphere above individual) – vitamin D production, sunburn, DNA damage, skin cancer

68
Q

cardiopulmonary responses

A

Hyperventilation from reduced arterial Po2 reflects the most important and clear-cut immediate response of native low-landers to altitude exposure

Resting blood pressure increases in early stages of altitude adaptation​

Increases in H.R. and Q

69
Q

fluid loss

A

Ambient air in mountainous regions remains cool and dry, allowing body water to evaporate as inspired air becomes warmed and moistened in respiratory passages​

Respiratory water loss, urine production​ (Lose up to 25% plasma volume​)

Fluid loss becomes pronounced for physically active people because of large daily total sweat loss and exercise pulmonary ventilation

70
Q

catecholaimne response

A

Sympathoadrenal activity progressively increases over time during rest and exercise with altitude​

increased BP & HR at altitude relate to steady rise in plasma levels and excretion rates of epi

increased sympathoadrenal activity contributes to regulation of BP, vascular resistance, & substrate mixture during short & long-term hypobaric exposures

71
Q

hematologic alterations

A

Increase in blood’s oxygen-carrying capacity provides important longer-term adjustment to altitude exposure​

72
Q

two factors account for hematologic alterations

A

initial decrease in plasma volume

increase in erythrocytes and hemoglobin synthesis

73
Q

cellular adaptations

A

Remodeling of capillary diameter and length with formation of new capillaries​

Improved microcirculation to reduce oxygen diffusion distance between blood and tissue​

Increased myoglobin (augments O2 storage)​

Small increase in mitochondrial number and concentration​

Slight right shift of oxy-hemoglobin dissociation curve (more unloading)​

Increased 2,3-DPG concentration​

Increased EPO

74
Q

body mass & composition

A

Basal metabolic rate ​

Increased Thyroxine secretion​

Increased Catecholamine secretion​

Must increase food intake to maintain body mass​

More reliance on glucose versus fat​

Anaerobic metabolism= increased lactic acid​

Lactic acid production decreases over time​

No explanation for lactate paradox

75
Q

sport performance

A

Aerobic exercise performance affected most by hypoxic conditions at altitude​

VO2max decreases as a percent of sea level VO2max ​

Given task still has same absolute O2 requirement​

Higher sea-level VO2max —> easier perceived effort

lower sea-level VO2max —> harder perceived effort

76
Q

live low, train high (LLTH)

A

has little to no enhancing benefit

Wilbur 2007 - small # of significant improvement in blood parameters, aerobic capacity, or work performance

76
Q

blood doping

A

Increasing the number of red blood cells either by transfusion or by the use of erythropoietin (EPO) to boost the production of red blood cells; typically not permitted and of unknown efficacy​

450-1800 ml of blood taken usually 12-16 weeks prior to event​

Re-infused about a week before event

Exercise Physiology (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions