energy systems
Why would you switch from the first energy system to the second?
creatine phosphate runs out
What is heart rate and stroke volume at rest and then during maximal exercise in an 20 year old untrained male?
HR: 70-200 bpm
SV:70-125 mL/beat
How does skinfold testing measure body composition?
-comes subcutaneous fat to total body fat
-uses calipers to "pinch" and measure subcutaneous fat over seven different sites
What hormone is inhibited when you drink alcohol?
Anti-Diuretic hormone (ADH)
what are receptors in the skin called that provide peripheral input to the hypothalamus?
thermal receptors
What is the work to rest ratio for the immediate energy system?
>1:3
What is cardiac output and AVO2-difference at rest and then during maximal exercise in an 20 year old untrained male?
CO:5 L/min-25 L/min
AVO2: 5-15 %/mL
How does bioelectrical impedance measure body composition?
-sends electrical current through tissues, fat will impede signal, muscle will conduct signal
What two hormones are secreted by the pituitary gland?
growth hormone and ADH
What hormone is inhibited during exercise in order to conserve fluid while exercising in the heat?
ADH
What is a by product of the non-oxidative energy system?
lactic acid
What is VO2 at rest and then during maximal exercise in an 20 year old untrained male?
absolute:0.25-3.2 L/min
relative: 3.5-47 ml/kg/min
What method of force production in the muscle is most important?
recruitment of motor units
DAILY DOUBLE
What does aldosterone regulate?
sodium reabsorption in the renal tubules
What is our body temperature normally? How many degrees does it fluctuate throughout the day?
98.6 + or - 1.8 degrees
DAILY DOUBLE
How long does each energy system last?
1. 10-20 sec
2. 20-90sec
3. 90 sec....
what is the Bohr effect?
shift in the O-Hb curve to the right and downward with a decrease in pH and an increase in temp.
-positive result, hemoglobin can now release O2 to the muscles more easily.
*DAILY DOUBLE*
What is the principle of orderly recruitment?
-based on force needed, not the speed of the movement
-type 1, then 2A, then 2x
What is the difference between insulin and glucagon?
insulin prevents hyperglycemia and glucagon prevents hypoglycemia
What is one factor the affects evaporative heat loss?
surface area of skin exposed
temp/humidity of ambient air
convective air currents
When running a marathon where you don't stop and then sprint to the end, list the energy systems used in order
1. immediate
2. non-oxidative
3. oxidative
4. non-oxidative
Explain two important features of the oxyhemoglobin dissociation curve
1. As PO2 increases there is an increase in the percent saturation to O2 to hemoglobin (reverse is also true)
2. The relatively flat upper portion of the curve represents a protective effect
3. the steep middle and lower portion of the curve represents that when there is a small drop in PO2, there is a large drop in %O2 saturation to hemoglobin
What is muscle architecture? Which arrangement generates the most force?
-the arrangement of muscle fibers relative to the axis of force generation
-multipennate
What percentage of sympathetic hormones released by the adrenal medulla is made up of norepinephrine?
20%
name three positive adaptations of heat acclimation
•Improvement in the ability to get rid of excess body heat
•Decreased body core temperature for a given submaximal work rate
•Lowered threshold for start of sweating
•Sweating increases and becomes more dilute
•Blood flow to skin is reduced; more blood is available to muscles
•Blood volume increases
•lower heart rate
•Stroke volume is increased