Week 9 Flashcards
1
Q
Radiation accounts for ____% of heat loss at room temperature
A
60%
2
Q
Radiation definition
A
molecules within the body are vibrating which creates heat in the form of electromagnetic waves that is given off
3
Q
conduction definition
A
transfer of heat between two objects of different temperatures that are in direct contact with eachother
4
Q
heat flows from
A
the warmer object to the colder object
5
Q
heat conduction in water is
A
25x greater than in the air
6
Q
convection definition
A
transfer of heat between the surface of the body and the air because of the circulation of air/water molecules next to the skin (wind chill index)
7
Q
evaporation definition
A
the transfer of heat from the body surface through the change of liquid water to gaseous water vapour
8
Q
evaporation is the human bodies major
A
physiological defence against overheating
9
Q
heat illness usually occur in
A
high heat and high humidity
10
Q
no evaporation can occur if the air is
A
100% saturated with water vapour
11
Q
what reduces evaporation?
A
helmets/clothing
12
Q
humans normal core temp
A
36.5-37.5 *C
97-99 *F
13
Q
what are the tolerable ranges of core heat temperature?
A
+6 *C and -10 *C
14
Q
How do we generate heat?
A
- basal metabolic rate
- exercise
- shivering
- food digestion
15
Q
basal metabolic rate
A
- heat production when resting increases about 1.3 *C/hour
- 75 kcal/hr
16
Q
exercise
A
increases heat production 10-20x BMR
17
Q
shivering
A
involuntary muscular activity produces 350 kcal/hr
18
Q
food digestion
A
raises metabolic rate above fasting level
18
Q
types of thermal receptors
A
- central receptors - hypothalamus
- peripheral receptors - skin
18
Q
thermoregulatory system maintains a constant internal body temp of
A
37 *C
- called the reference temperature
19
Q
referance temperature rises during exercise which allow for
A
- increase rate of metabolic rxns
- increased rate of gas/metabolite diffusion
- decreased viscosity of blood
20
Q
central receptors details
A
- sensitive to arterial blood temperature
21
Q
peripheral receptors details
A
- sensitive to hot and cold
22
Q
both types of thermal receptors can initiate
A
voluntary or involuntary regulation through effectors
23
Effectors of temperature regulation
- skeletal muscles
- smooth muscles
- sweat glands
- certain endocrine glands
24
skeletal muscles
we can shiver or do PA to generate heat
25
smooth muscles
- contract to constrict the arteriole and reduce BF, or they can relax to enhance BF
- conserve heat = reduce BF to periphery
- lose heat = enhance BF to periphery
26
certain endocrine glands
- thyroid and adrenal medulla
- secrete hormones that increase basal metabolic rate
26
Sweat glands
to lose heat through evaporation we sweat
27
exercising in hot environments
- puts stress on the circulatory system
- sweat loss reduces BV and SV
- HR is higher for a given workload
28
challenges to thermoregulation due to excessive sweat loss
reduced plasma volume which causes
- reduced CO and oxygen transport
- interference with temp regulation
29
heat disorders
1. heat cramps
2. heat exhaustion
3. heat stroke
30
athletes susceptible to heat disorder because
1. they are competitive
2. clothing & equipment
3. denied water
31
heat disorder factors
- heat exposure
- loss of water and salt
- heat storage
32
preventing heat disorders
acclimatization
shade
schedule
gear
colours
expose skin
clothing
33
acclimation is when
the environment is artificially induced and a physiological adaptation occurs
34
acclimatization is the
beneficial physiological adaptations that occur during repeated exposure
35
factors needed to quantify environmental heat stress
- ambient temperature
- environmental radiation
- humidity levels
36
if in direct sunlight
add 8 *C
37
if wearing protective clothing
add 6*C
38
goal of fluid replacement
to maintain plasma volume
39
how much fluid per hour of vigourous exercise?
200-800mL
40
you should pee
5 clear times a day
41
checking colour of urine accounts for
body size
42
it is usually more important to replace water than ions because
sweat is hypotonic, it contains less particles than in water
43
sports drinks can be beneficial during
long, stressful workouts in hot and humid conditions
44
water is more beneficial during
less intense exercise
45
maintaining high CHO
allows the athlete to work at higher intensities
46
recommended ratio of fructose to glucose is
2:1
47
fluid replacement guidlines
- hydrate properly before exercise
- replace fluid to maintain less than a 2% loss in body weight
- drink cool beverages
- drink frequently
- after workout replenish fluids at a rate of 0.5L for every 0.5kg of body weight lost
48
hyponatremia definition
- sodium deficiency in the blood
- can occur via excessive water ingestion/retention, excessive sweating, not enough Na in diet
49
Dipsomania definition
- water intoxication
- brain swelling, pressure against the skull, heart failure, convulsions, cessation of breathing
50
neuroendocrine system functions
- maintains homeostasis
- how we respond and adapt to training stimulus
- essential to exercise and diet
51
main effect of the SNS
is to prepare the body for physical activity
52
main effect of the PNS
is to control responses during rlaxation
53
endocrine system secretes hormones directly into
the blood stream to target specific cells
54
major hormones of the endocrine system
testosterone, insulin, glucagon, adrenaline, cortisol
55
chronically elevated cortisol levels
- destroy healthy muscle/bone
- slow down healing and cell regeneration
- promote fat storage around visceral organs
- weaken the immune system
56
the endorcrine systems speed
slow to initiate but prolonged response
57
the nervous system speed
fast signalling but short lived responses
58
neuroendocrine integration definition
nervous system and endocrine system work together to regulate physiological functions
59
the brain controls
the secretion of hormones to maintain homeostasis
60
catabolism definition
breakdown of molecules into smaller units to release energy
61
anabolism definition
construction of molecules from smaller units
62
immediate catabolic response to acute exercise
- neural sympathetic response is triggered, secreting ACTH, releasing E and NE
- produces cortisol, increases BP and respiration
- cortisol depresses the immune system because it is not needed for exercise
63
chronic catabolic response to exercise
- increased cortisol levels cause insulin resistance and diabetes
- causes visceral fat storage
64
acute inflammation is
normal and beneficial
- increased blood plasma and WBC which cause pain
65
chronic inflammation is
characterized by the simultaneous destruction of damaged cells and initiation of tissue repair
66
what type of muscle contraction cause the worst DOMS
eccentric muscle contractions but form less lactate than concentric muscular contractions
67
DOMS peak
24-72 hours after exercise
68
DOMS is associated with
loss of coordination and strength and decreased range of motion
69
DOMS mechanisms
1. mechanical damage to muscle structure, calcium accumulation, myofibril and membrane breakdown
2. acute inflammatory response increases swelling
70
causes of chronic inflammation
1. excessive exercise
2. diet
3. inability to cope
4. environmental stressors
71
acute anabolic response to exercise
occur after exercise
- post exercise insulin replenishes glycogen
- growth hormone
72
chronic anabolic response to exercise
testosterone and GH are elevated in 15-30min after resistance exercise
73
exercises at high intensities increase secretion of
GH, insulin like growth hormone, testosterone
74
the more intense a workout the more
anabolic hormones are released after exercise
75
testosterones fluctuations
highest in the monring, taper off as the day goes on
- this does not mean that the morning is the best time to exercise
76
High Glucose
elevatedlevels of cortisol cause the pancrease to become insulin resistant
- can lead to obesity, diabetes, heart disease
77
hormonal effects of sleeping & naps
- test released during parts of sleep cycle
- GH levels raised
- Blue light decreases melatonin
- naps & periods of relaxation decrease BP
