Muscle Physiology Lab Report
267-269, 277-280
* Direct calorimetry uses the measurement of heat production as an indication of metabolic rate. * Indirect calorimetry estimates metabolic rate via the measurement of oxygen consumption.
* Energy expenditure can be expressed in L•min-1, kcal•min-1, ml•kg-1•min-1, METs, and kcal•kg-1•hr-1. * To convert L•min-1 to kcal•min-1, multiply by 5.0 kcal•L-1. * To convert L•min-1 to ml•kg-1•min-1, multiply by 1000 and divide by body weight in kilograms. * To convert ml•kg-1•min-1 to METs or kcal•kg-1•hr-1, divide by 3.5 ml•kg-1•min-1.
Efficiency:
* Exercise work rate * Efficiency decreases as work rate increases * Speed of movement * There is an optimum speed of movement and any deviation reduces efficiency * Muscle fiber type * Higher efficiency in muscles with greater …show more content…
Vasodilation reduces vascular resistance and therefore increases blood flow.
Also aided by recruitment of cappilaries- at rest only 5-10% of capillaries are open, all are open during heavy exercise.
**level of vasodilation regulated by metabolic need of the muscle (intensity and # of motor units recruited determines blood flow to active muscle fibers) during exercise, vascular resistance in skeletal muscle decreases and vascular resistance to flow in the visceral organs/other inactive tissue increases. *because on increased sympathetic output to these organs regulated by CV control center.
*increase in visceral vasoconstriction during exercise decreases blood flow to viscera by 20-30% resting value.
During exercise in upright position, SV reaches plateau at 40% VO2 max, therefore, at work rate about 40% VO2 max, the rise in cardiac output (Q) is due to increased HR
* Direct calorimetry uses the measurement of heat production as an indication of metabolic rate. * Indirect calorimetry estimates metabolic rate via the measurement of oxygen consumption.
* Energy expenditure can be expressed in L•min-1, kcal•min-1, ml•kg-1•min-1, METs, and kcal•kg-1•hr-1. * To convert L•min-1 to kcal•min-1, multiply by 5.0 kcal•L-1. * To convert L•min-1 to ml•kg-1•min-1, multiply by 1000 and divide by body weight in kilograms. * To convert ml•kg-1•min-1 to METs or kcal•kg-1•hr-1, divide by 3.5 ml•kg-1•min-1.
Efficiency:
* Exercise work rate * Efficiency decreases as work rate increases * Speed of movement * There is an optimum speed of movement and any deviation reduces efficiency * Muscle fiber type * Higher efficiency in muscles with greater …show more content…
Vasodilation reduces vascular resistance and therefore increases blood flow.
Also aided by recruitment of cappilaries- at rest only 5-10% of capillaries are open, all are open during heavy exercise.
**level of vasodilation regulated by metabolic need of the muscle (intensity and # of motor units recruited determines blood flow to active muscle fibers) during exercise, vascular resistance in skeletal muscle decreases and vascular resistance to flow in the visceral organs/other inactive tissue increases. *because on increased sympathetic output to these organs regulated by CV control center.
*increase in visceral vasoconstriction during exercise decreases blood flow to viscera by 20-30% resting value.
During exercise in upright position, SV reaches plateau at 40% VO2 max, therefore, at work rate about 40% VO2 max, the rise in cardiac output (Q) is due to increased HR