Special Topics, Topnotch Flashcards
Part of brain that regulates temp
Hypothalamus
Location of sensors for temp regulation
Skin and hypothalamus
Radiator system of the body
Skin
Mechanisms of heat loss, greatest to least
Radiation > evaporation > conduction to air > conduction to objects
Interleukins that mediate fever
IL-1 and IL-6
Excessive sweating causing fainting
Heat exhaustion
High temp causes tissue damage and impaired responses
Heat stroke
Substances that cause malignant hyperthermia
Succinylcholine and halothane
Antidote for malignant hyperthermia
Dantrolene
M vs F: Strength per sq.cm of x-sec area
Equal
Energy system active during the first 8-10 sec of exercise
Phosphagen energy system
Energy system active 1.3-1.6 mins after phosphagen system is used up
Glycogen-lactic acid system
Energy system that is limited by availability of energy
Aerobic system
Supplies 50% of energy of aerobic system after 3-4 hours
Fats
How long does it take to recover muscle glycogen
2 days
Increase in muscle strength is ALWAYS due to
Increase in muscle size
Maximal breathing capacity
150-170L/min
Pulmonary ventilation during maximal exercise
100-110L/min
Resting CO in normal adult
5L/min
CO in exercising athlete
30L/min
CO in exercising non-athlete
20L/min
CO at maximal exercise
90% of maximun
___% of nutrient energy is converted to muscles work
25
Temp that causes heat stroke
> 42C
Sweat glands acclimatize to hot and humid weather because of
Aldosterone
Hormone that causes muscle strength and aggressiveness but can also cause MI and stroke
Testosterone
Most important effect of high altitude
Decreased mental proficiency
Altitude at which seizures may occur
18,000ft
Altitude at which coma and death may occur
23,000ft
Mechanisms for acclimatization to low PO2 (5)
1) Inc pulmonary ventilation by 1.65x in a few minutes to 5x in a few days
2) Polycythemia
3) Increase diffusing capacity of O2 and inc 2,3 bpg
4) Angiogenesis
5) Inc ability of cells to use O2 despite low PO2 via inc in mitochondria and oxidative enzymes
Mechanisms of acute mountain sickness
1) Acute pulmonary edema
2) Acute cerebral edema
Mechanisms of chronic mountain sickness
1) Pulmonary vasoconstriction
2) Right sided heart failure
Unit of force equal to the force exerted by gravity to which the body is subjected when it is accelerated
G force
Positive G vs Negative G: More dangerous due to shunting of blood to LE hence away from brain
Positive G
G that may cause LOC and death
+6 to +10
G that may cause vertebral fracture
20
G that may result in red-out of the eyes and transient psychotic disturbances
Negative G
Negative G that may result in death
-20
Constant speed that a freely falling object eventually reaches and prevents further acceleration
Terminal velocity
Speed of terminal velocity
175 ft/sec
A parachute reduces speed of skydiver to
1/9th terminal velocity
O2 in a sealed aircraft
20% at 760 mmHg
Decreased as a chronic effect of being in space (5)
1) Blood volume
2) RBC
3) Muscle strength
4) Max CO
5) Ca and PO4 in bones
Depth at which Nitrogen pressure causes joviality
120ft
Depth at which Nitrogen pressure causes drowsiness
200-250ft
Depth at which there is raptures of the depths
Beyond 250ft
Manifestations of decompression sickness (3)
1) Bends
2) Chokes
3) Caisson’s disease
Gas used beyond 250ft to prevent decompression sickness
Helium
