KAAP 430*- Final

0.0(0)
studied byStudied by 0 people
learnLearn
examPractice Test
spaced repetitionSpaced Repetition
heart puzzleMatch
flashcardsFlashcards
Card Sorting

1/123

flashcard set

Earn XP

Description and Tags

Health

Study Analytics
Name
Mastery
Learn
Test
Matching
Spaced

No study sessions yet.

124 Terms

1
New cards
homothermic
internal body temp regulated & kept nearly constant despite environmental temp changes
2
New cards
thermoregulation
regulation of body temp around a physiological set point
3
New cards
normal body temp
36.1-37.8 C | 97-100 F
4
New cards
ATP breakdown
25% -> cellular work (W)

75% -> metabolic heat (M)
5
New cards
types of dry heat exchange
\- conduction (K)

\- convection (C)

\- radiation (R)
6
New cards
conduction
heat transfer through direct molecular contact (negligible)
7
New cards
convection
heat transfer by movement of gas or liquid across a surface
8
New cards
radiation
heat loss in forms of infared rays
9
New cards
insulation
resistance to dry heat exchange

ideal insulator -> still layer of air
10
New cards
evaporation
heat loss via phase change from liquid to gas

primary heat loss during exercise (\~80%)
11
New cards
effect of humidity of heat loss
as humidity increases, evaporation decrease

(prolonged evaporation via sweat = dehydration)
12
New cards
heat balance equation
M-W ± R ± C ± K-E\=0
13
New cards
heat loss equation
M ± R ± C ± K - E < 0
14
New cards
heat gain equation
M ± R ± C ± K - E \> 0
15
New cards
can briefly withstand core temps of...
< 35 C

> 41 C
16
New cards
core temp greater than this inhibits physiological function
\> 40 C
17
New cards
preoptic-anterior hypothalamus (POAH)
\- body's thermostat

\- receives input from sensory thermoreceptors

\- activates thermoregulatory mechanisms
18
New cards
sensory receptors
\- peripheral: in skin

\- central: in brain & spinal cord
19
New cards
effectors
\- muscles & glands

\- respond to signals from the brain to regulate body temp

\- includes endocrine gland
20
New cards
effects of heat on cardiovascular function
\- skin arterioles VD to increase convection heat loss

\- POAH triggers SNS (increased cardiac output & VC in nonessential tissues)

\- blood volume decreases (sweating)

\- SV can't increase due to blood pooling
21
New cards
cardiovascular drift
\- occurs in prolonged exercise in hot conditions

\- heart rate increases to compensate for decreased blood volume
22
New cards
limitations to exercise in heat
\- cardiovascular system overload

\- critical temperature theory
23
New cards
cardiovascular system overload
\- heart can't provide sufficient blood flow to both exercising muscles and skin

\- especially in untrained / nonacclimated athletes
24
New cards
critical temperature theory
\- brain shuts down exercise at \~40-41C

\- limitation in trained / well acclimated athletes
25
New cards
only avenue of heat loss in hot conditions
evaporation (sweating)
26
New cards
sweat electrolyte content
\- duct reabsorbs Na+ and Cl-

\- light sweating: dilute sweat
27
New cards
training and sweat composition
\- more sensitive to aldosterone

\- reabsorb more Na+ and Cl-
28
New cards
sweat loss during exercise
\- can lose 1.6-2.0L (2.5-3.2% body weight) each hour

\- increased sweating -> decreased blood volume -> decreased cardiac output
29
New cards
hormonal control of fluid balance
\- adrenal cortex & posterior pituitary gland

\- loss of water & electrolytes triggers release of aldosterone & ADH
30
New cards
aldosterone
retains Na+ at kidneys
31
New cards
ADH
vasopressin; retains water at kidneys
32
New cards
risk factors for exercise in heat
1\. metabolic heat production

2\. air temperature

3\. humidity

4\. air velocity (convection)

5\. radiant heat sources

6\. clothing
33
New cards
wet-bulb globe temperature
\- reflects physiological stress

\- measures convection, evaporation, & radiation
34
New cards
severity of heat illness
lowest: heat cramps

mid: heat exhaustion

highest: heatstroke
35
New cards
heat cramps
\- severe painful cramping of large muscles

\- triggered by Na+ losses & dehydration

\- more common in heavy sweaters

\- treated by cooling down & dinking electrolytes
36
New cards
heat exhaustion
\- fatigue, dizziness, nausea, vomiting, fainting, weak rapid pulse

\- caused by severe dehydration from sweating

\- blood flow needs of muscle and skin cant be met (low BV)

\- thermoregulatory mechanisms functional but overwhelmed

\- more common in unfit or unacclimated people

\- treated by cooling person down
37
New cards
heatstroke
\- life threatening

\- thermoregulatory mechanism failure

\- core temp >40 C

\- mental decline: confusion, disorientation, unconsciousness

\- must cool whole body ASAP
38
New cards
acclimation
short term adaptation to environmental stressor (days / weeks)
39
New cards
acclimatization
long term adaptation to environmental stressor (months / years)
40
New cards
acclimation to heat
\- cardiovascular function optimized (decreased heart rate, increased cardiac output)

\- widespread sweating earlier, more dilute

\- lower core temp during exercise

\- plasma volume increases due to increase oncotic P
41
New cards
sex differences in heat
\- lower sweat rate in women

\- more active sweat glands but less sweat production per gland

\- women have advantage in humid climates, disadvantage in hot, dry climates
42
New cards
cold stress
any environmental condition causing loss of body heat
43
New cards
effects of cold
\- POAH triggers peripheral VC

\- nonshivering thermogenesis

\- skeletal muscle shivering

\- cerebral cortex triggers behavioral adaptations
44
New cards
cold habituation
\- occurs after repeated cold exposures without significant heat loss

\- VC & shivering blunted

\- core temp allowed to decrease more
45
New cards
metabolic acclimation
\- occurs after repeated cold exposures with heat loss

\- enhanced metabolic & shivering heat productions
46
New cards
insulative acclimation
\- when increased metabolism cant prevent heat loss

\- enhanced skin VC ( increased peripheral tissue insulation)
47
New cards
overdressing in cold climates
\- can be dangerous

\- causes sweating which increases evaporation
48
New cards
how body composition increases insulation
\- increased inactive peripheral muscle

\- increased subcutaneous fat

\- decreased surface area:mass ratio (bigger person)
49
New cards
windchill
\- refers to speed not temp

\- based on cooling effect of wind

\- increases convection heat loss

\- higher windchill increases risk of freezing tissues
50
New cards
cooling effects of liquid vs air
\- heat loss 4x faster in cold water

\- core temp constant until water temp < 32 C / 89.6 F

\- core temp drops 2.1 C per hour in 15 C water

\- heat loss is faster in moving water & slower with exercise
51
New cards
muscle function in cold
\- decreases

\- altered fiber recruitment -> lower contractile force

\- shortened velocity and decreased power

\- affects superficial muscles
52
New cards
fatigue in the cold
\- metabolic heat production decreases

\- energy reserve is depleted with endurance exercise

\- potential for hypothermia
53
New cards
FFA in cold
\- increased catecholamine secretion but no increase in FFA

\- VC in subcutaneous fat decreases FFA mobilization
54
New cards
glucose metabolism in cold
\- blood glucose maintained well during cold exercise

\- muscle glycogen utilization increased

\- hypoglycemia suppresses shivering
55
New cards
hypothermia
\- core temp 29.5-34.5: thermoregulatory function compromised

\- core temp
56
New cards
cardiorespiratory effects of cold
\- low core temp leads to slow HR (SA node)

\- may cause arrhythmia

\- doesn't damage ventilatory tissues

\- may decrease ventilation rate and volume
57
New cards
treatment for mild hypothermia
\- remove from cold

\- dry clothing, blankets

\- warm drink
58
New cards
treatment for severe hypothermia
\- gentle handling to avoid arrhythmias

\- gradual rewarming

\- may require medical supervision
59
New cards
frostbite
\- excessive VC > lack of O2 & nutrients > tissue death

\- gradual rewarm (no risk of refreezing)
60
New cards
exercise-induced asthma (cold)
\- affects 50% of winter sport athletes

\- excessive airway drying
61
New cards
partial pressure of oxygen
\- portion of barometric pressure exerted my oxygen

\- reduced PO2 at altitude limits performance
62
New cards
hypobaria
\- reduced Pb seen at altitude

\- results in hypoxia & hypoxemia
63
New cards
hypoxia
low oxygen saturation / supply of the tissues
64
New cards
hypoxemia
low oxygen content in the blood
65
New cards
change of PO2
\- percent of O2 in air doesn't change

\- change results from decrease Pb at higher altitudes
66
New cards
humidity at altitude
\- cold holds very little water

\- air at altitude is very cold & dry

\- faster dehydration via skin & lungs
67
New cards
altitude
> 1,500 m

few physiological effects below that
68
New cards
low altitude
\- 500-2,000 m

\- no effects on well being

\- performance may be lower, but restored by acclimation
69
New cards
moderate altitude
\- 2,000-3,000 m

\- effects unacclimated people

\- performance and aerobic capacity declines

\- performance may or may not be restored by acclimation
70
New cards
high altitude
\- 3,000-5,500 m

\- acute mountain sickness

\- performance declines, not restored by acclimation
71
New cards
extreme high altitude
\- >5,500

\- severe hypoxic effects
72
New cards
pulmonary response to acute altitude (rest & submaximal)
\- ventilation increases immediately

\- decrease PO2 stimulates chemoreceptors in aortic arch & carotids

\- increased tidal volume and respiration rate for several hours-days
73
New cards
hyperventilation
\- increase ventilation at altitude

\- alveolar PCO2 decreases, so gradient increases and there is an increased loss

\- respiratory alkalosis
74
New cards
respiratory alkalosis
\- high blood pH

\- oxyhemoglobin curve shifts left

\- prevents hypoxia-driven hyperventilation- kidneys excrete more bicarbonate to decrease buffering and reverse alkalosis
75
New cards
pulmonary diffusion at altitude
\- at rest, does not limit gas exchange

\- hypoxemia is a direct reflection of low alveolar PO2
76
New cards
oxygen transport at altitude
\- decreased alveolar PO2 causes decreased hemoglobin saturation

\- curve shifts left to minimize desaturation
77
New cards
O2 diffusion at altitude
\- 15 mmHg diffusion gradient

\- significant reduction in diffusion into muscles
78
New cards
left shift of oxyhemoglobin curve
\- higher saturation at lower pressures

\- adaptation to combat desaturation at lower PO2 at altitude
79
New cards
vascular system at altitude (short term)
\- plasma volume decreases (up to 25%) within a few hours

\- respiratory water loss & increased urination

\- short term increase in hematocrit
80
New cards
vascular system at altitude (long term)
\- red blood cell count increases

\- hypoxemia triggers EPO release from kidneys

\- increased RBC production in bone marrow

\- long term increase in hematocrit
81
New cards
cardiac system at altitude (short term)
\- cardiac output increases (despite decrease in plasma & stroke volume)

\- increased SNS activity > increase in HR

\- inefficient
82
New cards
cardiac system at altitude (muscles)
\- after a few days muscles extract more O2

\- increases a-v O2 difference

\- reduces demand for cardiac output
83
New cards
cardiac system at altitude (long term)
\- decreased stroke volume due to decrease plasma volume

\- decreased HR due to decreased SNS responsiveness

\- decreased VO2 max due to decreased cardiac output & decreased PO2 gradient
84
New cards
metabolic rate at altitude
\- basal metabolic rate increases (increased thyroxine and catecholamine secretion)

\- decreased appetite but must increase food intake to maintain body mass

\- increased anaerobic metabolism
85
New cards
glucose vs fat
at altitude, glucose (carbs) provide more energy per liter of oxygen
86
New cards
effects of increase anaerobic metabolism
\- increase lactic acid

\- production decreases over time (dk why)
87
New cards
VO2max at altitude
\- VO2max decreases as altitude increases

\- due to decreased arterial PO2 and cardiac output

\- decreases as a percentage of sea level VO2max

\- lower sea-level VO2max > higher perceived effort (even though task has same absolute O2 requirement)
88
New cards
Mt. Everest ascent study
\- climbers' VO2max decrease from 62 to 15

\- if sea level VO2 is
89
New cards
anaerobic performance at altitude
\- unaffected

\- ATP-PCr and anaerobic glycolytic metabolism not affected by lower PO2 (minimal oxygen requirements)

\- thinner air > less resistance

\- can have improved swim & run times (
90
New cards
acclimation to altitude
\- improves performance, but not to that of sea level

\- takes 3 weeks at moderate altitude (+1 week for every additional 600m)

\- lost within 1 month at sea level
91
New cards
changes from chronic exposure to high altitude
\- ventilation increases & stays elevated

\- stroke volume drops & recovers slightly

\- heart rate drops immediately & then rises (receptors not as sensitive to SNS)

\- cardiac output drops & remains lower

\- VO2 max drops and stays lower
92
New cards
strategies for sea-level athletes competing at altitude

1. compete immediately
2. train high for 2 weeks
93
New cards
(1) compete ASAP
\- doesn't give benefits of acclimation

\- too soon for adverse effects
94
New cards
(2) train high for 2 weeks
\- worst adverse effects of altitude over

\- aerobic training at altitude not as effective (train at lower intensity)
95
New cards
“live high, train low”
\- best of both worlds

\- permits passive acclimation to altitude

\- training intensity not compromised by low PO2

\- shows significant improvement in 5k trial

\- aerobic performance and VO2max improved
96
New cards
artificial altitude training
\- attempt to gain benefits of hypoxia at sea level

\- breath hypoxic air 1-2 hours a day, train normally

\- no improvements
97
New cards
natural vs artificial live high train low
\- natural best for elite athletes

\- nonelite athletes may benefit from artificial
98
New cards
acute altitude (mountain) sickness
\- onset 6-48h after arrival (most severe days 2-3)

\- headache, nausea / vomiting, dyspnea, insomnia

\- can develop into more lethal conditions

\- incidence increases with altitude, rate of ascent, and susceptibility

\- causes: low ventilatory response, CO2 accumulates & causes acidosis
99
New cards
headache in altitude sickness
\- most common symptom

\- worse in morning & after exercise

\- hypoxia causes cerebral vasodilation which leads to stretching of pain receptors
100
New cards
altitude sickness insomnia
\- interruption of sleep stages

\- Cheyne-Stokes breathing prevents sleep

\- incidence of irregular breathing increases with altitude