Test 2 389 Flashcards
Hypothermia
core temperature below 35 degrees celsius or 95 degrees fahrenheit
temperature at homeostasis
37 degrees celsius
98.6 degrees farenheit
2 degrees celsius drop from 35 degrees C is associated with what condition?
maximal shivering
4 degrees C drop from 35 is associeted with
ataxia and apathy
ataxia
unctrlled muscular contraction
apathy
know something is wrong, but don’t care
6 degree drop from 35 C associated with
unconsciousness
drop greater 6 degrees C from 35 is
ventricular fibrillation, reduced brain blood flow, asystole, and death
asystole
no contraction= death
What four conditions occur when heat loss exceeds production?
Conduction
convection
radiation
evaporation
4 main reasons for heat loss
Temperature
Vapor Pressure
Wind
Water Immersion
Temp as factor for heat loss
gradient for convective heat loss, difference in temp so heat will go from hot to cold (heat rises)
Vapor pressure does what?
low water vapor pressure encourages evaporation
dry= increase heat loss & evaporation
Wind is example of what property
convection proptery
Winds impact on heat loss
rate of heat loss influenced by wind speed
wind speed encourages
evaporation so increasing heat loss
Water immersion rate of heat loss is .. ..
How come??
25x greater than air @ same temp because water is a better conductor and is denser, so temp is dispersed better onto body and constantly transferring heat faster
Hypothermia is influenced by
natural and added insulation, environmental temp, vapor pressure, wind, water immersion and heat production
Wind chill index describes how??
wind lowers the effective temperature at the skin such that convective heat loss is greater than what it would be in calm air at same temp
Water causes heat to . . . ?
be lost by convection twenty-five times faster than it would be by exposure to air of the same temperature
3 insulating factors
subcutaneous fat
clothing
amount of insulation required is lower during exs
Subcutaneous fat
great insulator, not great heat transfer/loss
especially effective in cold water
clothing is measured how and what does that measurement equate to?
1 clo unit= insulation needed to maintain core temp at rest at 21 degrees celsius, 50%RH and 6 m/min winds
RH
relative humidity
what does increased clo units mean?
if colder than 21 deg C, more human than 50%RH, and faster than 6m/min, the number of clo units will increase
As temp & activity increase, blank happens
clo units requirements decrease
How does body produce heat (heat production)?
Heat production from shivering increases upon exposure to cold
What is shivering
shivering is small muscle contractions to generate heat so ATP is breaking down making more heat
Shivering effect on o2 consumption? (VO2)
Earlier onset of shivering in lean men, VO2 increases
Fuel used for heat production
CHO and lipid, how much depends on intensity of shivering , type of diet, and muscle fiber type, and you can deplete glycogen
what determines fuel person used?
how trained person is and intensity of exs
Heavy exercise fuel used
carbs
light intensity
lipids
Fuel used for heat production
CHO and lipid, how much depends on intensity of shivering , type of diet, and muscle fiber type, and you can deplete glycogen
what determines fuel person used?
how trained person is and intensity of exs
Heavy exercise fuel used
carbs
light intensity
lipids
Characterisctics influencing responses to cold exposure
Gender and age
Genders influence to cold exposure response
At rest, women show faster reduction in body temperature then men since females have more subcutaneous fat so they have more surface so heat dissapates more anthropometry
Where is decrease in body temp similar in the both genders
in cold water
what age are people less tolerant to cold?
greater than 60 yrs old
Why do children experience faster fall in body temp?
faster metabolism so catabolism and anabolism is faster when cold, heat produced increase so more heat is given off/ loss
What is the primary natural insulation and is very effective in preventing rapid heat loss when a person is exposed to cold water ?
subcutaneous fat
Three common effects of hypothermia?
reduced coordination
slurred speech
impaired judgement
Treatment of hypothermia
Get person out of cold, wind, and rain Remove all well clothing provide warm drinks and dry clothes put person into sleeping bag, and w/ person if semiconsous Find them a source of heat
Hyperthermia
elevated body temperature
4 heat related issues from less severe to very dangerous
Heat syncope
Heat Cramps
Heat Exhaustion
Heat Stroke
Heat stroke
Medical emergency cuz person cannot regulate body temp, and the person may slip into a coma and die, can cool them down with conduction via ice bath, but too fast can lead to cardiac arrest
Treatment of hyperthermia
cold water immersion
When evironment is hot and humid
person cant sweat as much
Factors related to heat injury
fitness, sweat rate, and acclimatization
does higher fitness lower heat loss injury? why ??
Higher fitness lowers risk of heat injury since they will tolerate more work in heat, acclimatize faster, and sweat more. Fat people sweat less due to more insulation so they cannot cool down their body temp as well.
How does acclimatization happen?
10-14 days
low intensity, long duration
mod intensity, short duration
This will lower body temp and HR response and is best protection against heat stroke and exhaustion
WBGT
composite of temp, humidity, and solar radiation
dry bulb temp (T db)
air temp in shade, protected from humidity
black globe temp (T g)
radiant heat load in direct sunlight, black ball aborbs it
Wet bulb temp (T wb)
Humidity
index of ability to wick/absorb sweat
Most vital in determining overall heat stress (70% of total WBGT)
WBGT formula
WBGT= .7Twb + .2 Tg + .1Tdb
Increased dryness in air does what?
decreased temp and increase evaporation since more water will be picked, and will make WBGT decrease
Risk of heat stress depends on
WBGT
How does Twb work?
material/wick is in contact with both water and thermometer, air flows over the thermometer, evaporating water, the drier the air, the more water evaporates, and makes a cooler temperature
WBGT less than or equal to 50.0 degrees F
risk of hypothermia
WBGT 50-65 degress F
low risk of hypo- and hyperthermia
WBGT 65.1-72 F
caution: moderate risk of heat illness
WBGT 72.1-78 F
extreme caution: risk of hyperthermia increased for all
WBGT 78.1-82 F
extreme caution high risk for unfit, non-acclimatized ppl
WBGT greater than 82
Extreme risk of hyperthermia; cancel or postpone event, and is next to impossible to dissipate heat
of the WBGT variables what is the most important factor in determining overall heat stress?
water vapor pressure via Twb/ wet globe temp
WHAT decreases at higher altitude?
atmospheric pressure
Partial Pressure and altitude relationship
Same percentages of O2, CO2, N2 in air
Lower Pp of 02, CO2, N2
Hypoxia is not
hypoxemia,
Hypoxia defin
Low PO2 (altiude)
Normoxia
Normal P02 at sea level
Hyperoxia
Higher P02 like in hyperbaric chamber that is 100% oxyegn
Effect of Altitude on Performance short-term anaerobic performance
lower PO2 at altitude: little effect on performance
Why little improvement in Effect of Altitude on Performance short-term anaerobic performance?
Improves some due to lower air resistance depending on sports such as javelin, football kicker…
Effect of Altitude on Performance long-term aerobic performance and whY?
Lower PO2 results in poorer aerobic performance since they are not getting enough oxygen
What four components of the evironment decrease with altitude?
atmospheric pressure, PO2, air temp, and air density
The lower air density at altitude offers blank to high-speed movement (anaerobic), blank, and endurance blank blank.
The lower air density at altitude offers less resistance to high-speed movement, sprint performances are either not affected or are improved, and endurance performances decrease.
Decreased VO2max at higher altitude due to what?
lower o2 extraction, decreased arterial PO2, fall in maximal Q due to decreased HRmax and SV max at altitude
Decreased arterial PO2 what altitude?
moderate altitudes (4,000 m)
Fall in maximum cardiac output (Q) what height?
higher altitudes (6,000 m)q
Why Fall in maximum cardiac output (Q)?
Decreased maximal HR, SV at altitude
Elicits higher heart rate. . .why?
lower O2 content in arterial blood
Requires higher ventilation. . .why?
reduced # of O2 molecules per L of air
Adaptation to High Altitude
Production of more red blood cells
Lifetime altitude residents
In those recently arriving at altitude
Why is Production of more red blood cells an Adaptation to High Altitude?
Higher hemoglobin concentration via EPO
Counters desaturation caused by lower PO2
Where are adaptations less complete due to high altitude?
In those recently arriving at altitude
Have complete adaptations in arterial oxygen content and VO2 max
Lifetime altitude residents
Training for Competition at Altitude 3 things
Effect of training at altitude on VO2 max varies among athletes
Effect of training at altitude on VO2 max varies among athletes depends on what?
Due to degree of saturation of hemoglobin
Neuroendocrine system
Endocrine and nervous system working together
Endocrine sys releases
hormones
Nervous system uses
neurotransmitters
Endocrine glands release what how into what?
release hormones directly into the blood
Hormones do what to tissues
Alter the activity of tissues that possess receptors to which the hormone can bind (very specific)
Several classes of hormones based on chemical makeup?
Amino Acid derivatives
peptides/protein
steroids
What is blood hormone concentration ?
The effect of a hormone on a tissue is determined by the plasma concentration
4 determinators of blood hormone concentration
Rate of secretion of hormone from endocrine gland
Rate of Metabolism or excitation of hormone
Qty of transport protein
Changes in plasma volume
What impacts rate of secretion of hormone from endocrine gland? (2 things)
magnitude of input (chemicals)
stimulatory versus inhibitory inputs
Rate of metabolism or excitation of hormone is ctrlled by?
at the receptors and by the liver and kidneys
Qty of transport protein
steroid hormones
Factors that influence secretion of hormones . . .?
tba
Hormone-Receptor Interactions
Hormones only affect tissue with specific receptors
What is magnitude of effect dependent on?
[hormone]
# of receptors on the cell
affinity of the receptor for the hormone
Down-regulation
decrease in receptor # in response to high [h]
up-reg
increase in receptor # in response to low [h]
4 MOHA
Altering membrane transport
Tyrosine Kinase
Altering activity of DNA to modify protein synthesis
Activating second msgers via G proteins
example of altering membrane transport
insulin
Tyrosine kinase example
insulin and GH
altering activity of DNA to modify PS
roids hormones
Second messergers
cAMP
Ca++
Inositol triphosphate (IP3)
diacylglycerol (DAG)
Vitamin D is really what?
steroid hormone
Roid hormones have ability to do what?
ability to pass through cell membrane and nuclear membrane
cAMP
its cAMP, not the hormone itself, that elicits the cellular response . . .. 2nd msger
What uses cAMP mech?
Epinephrine/adrenaline
Ca++, ip3, and DAG allow what?
cellular resp, not hormone directly
GHRH and oxytocin use this mechanism
Ca and Phospholipase C Second msger mech
How hormones bring about their effects?
by modifying membrane transport, activating/supressing genes to alter protein synthesis, and activating second messengers (cAMP, Ca++, ip3, and DAG)
What are the two primary second msger mech?
cAMP sys (epineph) Ca++/IP3/DAG system (GHRH)
what are hormones secreted from?
endocrine glands
9 endocrine glands or secreters or organ secreter
Hypothalamus and Pituitary glands Thyroid and Parathyroid glands Thymus glands Adrenal Glands Pancreas Testes and ovaries adipose tissue (organ not gland)
Hypothalamus does what?
ctrls secretions from pituitary gland
Adenohypophysis/anterior pit gland secretes what 7 hormones?
ACTH FSH LH MSH TSH GH Prolactin
Posterior pit gland secretes what 2 hormones?
oxytocin
ADH
hypothalamus stimulates
release of hormones from the adenohypophysis gland called releasing factors or hormones
hypothalamus provides
hormones for release from neurohypophysis gland, and these are hormones directly from the hypothalamus
ACTH stimulates
cortisol release from adrenal glands
FSH regulates
reproductive cell production in men and women
LH stimulates
production of testosterone and estrogen
MSH
produce and release melanin in skin and hair
TSH
controls thyroid hormone release from thyroid gland
prolactin
milk poduction
GH stimulates
release of IGFs
IGF-1 in muscle is responsible for
muscle growth
GH three apsects
stimulates release of IGFs
Essential growth of all tissues
spares plasma glucose
Essential growth of all tissues via GH two things that
Amino acid uptake and protein synthesis
long bone growth
how does GH spare plasma glucose?
reduces the use of plasma glucose
increases gluconeogenesis
mobilizes fatty acids from adipose tissue
GH increases
protein synth in muscle and long bone growth
GH is used to treat what ?
treat childhood dwarfism and used by elderly and athletes for strength
GH has more what tthan what
adverse effect than benefits such as acromegaly
GH release during EXS
increases during EXS to mobilize FFA from adipose tissue and to aid in maintenance of blood glucose
ADH does what?
Reduces water loss from the body to maintain plasma volume
ADH favors
reabsorption of h2o from kidney tubules to capillaies
ADH release stimulated by and why?
low plasma volume due to sweat loss without replacement of water
ADH increases during
EXS to maintain plasma volume
Thyroid gland is stimulated by?
TSH
What est metabolic rate?
T3 and T4
permisive hormones
permit full effect of other hormones (catecholamines) by increasing # of receptors on tissue
calitonin regulates what? blocks?
Ca++ and blocks release from bone, stimulates excretion by kidneys
PTH is what?
primary hormone in plasma Ca++ regulation
PTH stimulates release from?
bone, stimulates reabsorption by kidneys
PTH converts what?
vit D into steroid hormone form to increase Ca absoprtion from gut
Adrenal Medulla secretes
catecholamines E ad NE
Catecholamines characteristics
fast-acting hormones
part of fight or flight response
E is primary secretion (80%)
Catecholmines bind to
adrenergic receptors
Catecholamine effects depnd on?
hormone used and receptor type, but generally ready body for exs (increase HR, FFA mobilization)
catecholamines use what mech
2nd msger mech
Mineralcorticods include? do?
aldosterone
maintenance of plasm Na+ and K+
glucocorticoids
cortisol
regulation of plasma glucose
sex roids
androgens and estrogens
support prepubescent growth
Aldosterone
Control of Na+ reabsorption and K+ secretion (Na/H2o ballance)
Regulation of blood volume and bp
Aldosterone is stimulated by what?
increased [K+]
decreased plasma volume
Cortisol maintains
maintenance of plasm glucose
Cortisol promotes what
protein breakdown for gluconeogenesis
cortisol stimulates
FFA mobilization and glucose release (glycogen breakdwn)
cortisol blocks
uptake of glucose into cell by promoting the use of FFA as fuel
cortisol is stimulated by what through what and is part of blank?
stimulated by stress via ACTH such as exercise, and is part of General Adaptation Syndrome (GAS)
GAS
Allows immunity maintenance in prolonged bouts of stress, but can fatigue itself allowing immunity depression
GAS alarm/resistnace phase role of cortisol
cortisol also released (to allow blood glucose maintenance)
Adrenal gland has 2 components called
medulla (inside) and cortex (outside)
Medulla secretes
fight or flight hormones and bind to adrenergic receptors
cortex secretes
androgenic hormones, aldosterone, andcortisol
cortisol is called what as well?
stress hormone
Adipose tissue
In addition to storing triglycerides, it also secretes hormones
2 hormones secreted by adipose tissue
Leptin and adiponectin
hight amounts of the hormone leptin is seen in people that are ?
obese individuals
Leptin directs
excess kcals into adipose tissue (protects muscle cells)
Adiponectin is seen in what ppl?
Lean ppl
Adiponectin increase what?
insulin sensitivity and fatty acid oxidation (decreases fat storage)
With increased fat mass/obesity? leads to what
High leptin levels and lower adiponectin (leptin resistant)
Leads to type 2 DM and low-grade inflamation
Obesity leads to how?
inflamation due to increased leptin and other inflamatory markers and decreased adiponectin
Pancreas has 2 functions what are these mofo?
exocrine and endocrine functions
pancreas secretes
Insulin from Beta cells AND glucogan from alpha cells
Insulin promotes
storage of glucose, AA, and fats
lack of insulin is called ?
DM
glucagon promotes
mobilization FFA and glucose
Insulin promotes storage of _____, or
nutrients or synthesis of glycogen (anabolism), muslce protein
Glucagon promotes ________ of
breakdown/ catabolism of stored fuels (glycogen, triglycerides, protein)
1) Of the four levels of heat illness, ________________________ is the one that is most life-threatening. When this occurs, the best way to cool the patient is to do what?
heat stroke
cold water immersion via ice bath to lower body temperature
2) Circle the correct choice for each instance: When you acclimatize to exercising in the heat, you should exercise either at low/moderate intensity for a short/long duration, or low/moderate intensity for a short/long duration.
low long
moderate short
3) Clothing will increase/decrease body temperature during exercise, and it will increase/decrease the amount of time to cool back to homeostasis during recovery.
increase
increase
4) Write the formula for the WBGT heat index temperature below, and circle the factor that contributes most:
WBGT=.7Twb + .2Tg + .1 Tdb
5) When air is dry, the wet bulb temperature will be high/low because the amount of water evaporating from the wick will be large/small.
loe
large
6) A low atmospheric PO2 condition is known as ___________________. This has a ___________________ effect on anaerobic performance, and a _____________________effect on aerobic performance.
hypoxia
favorable
unfavorable
7) Performing submaximal exercise at altitude causes heart rate and pulmonary ventilation to ____________________ compared to the same intensity at sea level. Both effects are due to the low __________________ at altitude.
Increase
Oxygen
8) One can acclimatize to a hypoxic condition. What occurs is the body will secrete more of the hormone _____________ so that more _____________________ will be produced.
EPO
RBC
9) The advantage of the “Live high, train low” premise is that by living high, you can produce more ____________________, and then use them when you train low, when you can maintain the training _________________ needed to prepare for competition.
RBCs
velocity/intensity
10) On the summit of Mt. Everest, your VO2max is approximately _______ mL/kg/min. Successful climbers have a high capacity for _____________________, which increases/decreases acidity.
15
hyperventilation
1) Hormones released from endocrine glands are releases directly into the _________________. These hormones will bind to ___________________ found in or on the cells of target tissues.
tba
2) The strength of the effect of a hormone is largely determined by the ____________________ of the hormone in the blood plasma, which can be determined by the rate __________________ of the hormone from endocrine glands.
tba
3) Downregulation refers specifically to the increase/decrease of hormone receptors in response to high/low concentration of the hormone.
tba
1) Upregulation refers specifically to the increase/decrease of hormone receptors in response to high/low concentration of the hormone.
tba
2) When insulin is secreted, it will bind to the ___________ subunit of its receptor, which is named _____________________________. When the binding occurs, it will cause the __________ subunit to add ___________________ to itself.
tba
3) Continuing from #5, the activated receptor will cause a cascade of signaling events in the cell, which will cause vesicles containing ______________ to move to the cell membrane to allow ___________________ to enter the cell.
tba
4) Steroid hormones exert their action by moving through the cell all the way into the ___________________. There, they will interact with the ___________ , which will result in synthesis of _________________.
tba
5) When epinephrine binds to its receptor in skeletal muscle tissue, it will activate _______________ embedded in the cell membrane. This then activates _______________ in the membrane, which will convert ATP in the cell into a molecule of ______________. This process will end when the enzyme _______________________ is activated.
tba
6) When growth hormone-releasing hormone binds to its receptor, after the G protein is activated, it will activate _____________ channels in the membrane, which will increase cytoplasmic __________________ levels. This will activate a protein called __________________, which will then activate a protein to cause the cellular response.
tba
7) Continuing from #9, the activated G protein can also activate a membrane protein called ___________________, which will act on a molecule known as _______________________. This molecule will split into two molecules, _______________________ and ______________.
tba
In alarm/resistance phase of GAS what happens?
ER RI AS VC DS PD MC HRI AD And cortisol released to allow blood glucose maintainence
