Lec 10- Skeletal Muscle Mechanics and Metabolism Flashcards
Atrophy
Muscle fibers become smaller; actin and myosin content decreases.
Hypertrophy
Muscle growth
Hyperplasia
An increase in the number of muscle cells.
Series elastic components
Tendons and connective tissue are elastic and absorb tension as muscle contracts.
Recruitment
More and more motor units are recruited, or stimulated to contract simultaneously.
Summation
AP add together to produce greater tension in the fiber than that produced by a single ap.
Tetanus
Rapid stimulation that does’t allow any time to relax. Maximal sustained contraction.
Twitch
Not considered to be normal, rare occurrence.
Isometric contraction
Exerted force does not cause load to move and length of fibers remains constant. More force/tension is generated.
Isotonic contraction
force remains constant as muscle changes length.
Motor unit
control a various number of muscle fibers.
The smaller amount of muscle fibers innervated = fine control.
Length-tension relationship
Length at which optimal force can be achieved during a tetanic contraction.
VO2 max
or maximal oxygen consumption, refers to the maximum amount of oxygen that an individual can utilize during intense or maximal exercise.
50-70% in healthy people
Lactate threshold
is % of max O2 uptake at which there is a significant rise in blood lactate levels
Oxygen debt
AKA EPOC
Takes while for O2 to go back to normal because it was lost due to exercise and is needed for metabolism of lactate acid (which was built up from anaerobic respiration)
