4.3.1 Muscle Physiology, Exercise, and Physical Conditioning Flashcards
What are the 3 important contractile properties of muscle?
Maximal force, speed of force, muscle fiber efficiency (force produced and amount of ATP used)
Determined by the fiber type
What are the three classifications of muscle fibers based on enzyme activity?
What happens when an alpha-motor nerve is stimulated?
All of the muscle fibers innervated by the alpha-motor nerve are stimulated
In an untrained person, if they start exercise, what will be the conversion sequence of muscle?
(From untrained to trained)
What type of muscle contraction creates a greater amount of force?
Eccentric contraction
Is it possible to change muscle fiber type?
Yes
What is the length-tension relationship b/t muscle?
What are the standard end points of the sarcomere?
Z line to Z line
What types of stimuli processes are part of the latency period?
How does greater # of sarcomeres in parallel change force production?
Greater maximal force
What characteristics are favored by long-term, low-intensity exercise?
Slow characteristics, power is low but production is more economical
Oxidative capacity - increased mitochondrial density is correlated with fatigue resistance
What are the three types of muscle fibers? Are they glycotic or oxidative? Fast or slow?
What allows for the production of tension?
Cross bridges b/t actin and myosin
What type of fibers are lost due to increased age?
Fast fibers
How can fiber types be differentiated histochemically?
Type of myosin
What three factors determine the production of force in an isolated muscle?
The sliding of the actin strand over the myosin strand during the contraction of muscle is called what?
The power stroke
What are the six steps/phases of the myosin engagement with actin during the power stroke?
What are the three types of stimulus frequency?
Is any force produced by simple twitches?
No, there is no sustained activation of muscle
What is responsible for the strength changes in the first 8 wks? After that?
1st 8 wks: neural factors
After 8 wks: hypertrophy factors
What is the “size principle”?
What is the conversion of muscle fibers as a result of inactivity?
What characteristics are favored by short-term, high-intensity exercise?
What is the purpose of strength/resistance training in the elderly
Maintaining some ballistic muscle strength and muscle mass in order to catch self if they’re going to fall
What is the order in which muscle fibers are activated?
Small muscle fibers must fire before the large muscle fibers. If the CNS knows that it needs a larger force, it can speed up the recruitment process.
How does more sarcomeres in series affect muscle force?
Same force over a greater distance
