Exercise Physiology Flashcards
Describe the various bands of the sarcomere
Z line: binding area for thin filaments, represents the sarcomere borders
M line: dark line in the middle of the sarcomere that contains proteins (myomesin) critical for organization and alignment of thick filaments
I band: light band either side of the Z line that contains thin filaments
H band: light area located in the middle of the A band that contains thick filaments
A band: dark area between two Z lines that contain both thick and thin filaments
Explain how motor neurons stimulate muscle contraction
Signals from CNS, conveyed by motor neurons are required to initiate and sustain muscle contraction
When a motor neuron sends out an action potential, its synaptic terminals release the NT Acetylcholine, which diffuses across the synapse to the plasma membrane of the muscle fiber
Explain the role of calcium in triggering the contraction of skeletal muscle
Calcium release from SER will bind to TnC of the troponin complex. When bound, it will cause troponin to move tropomyosin away from blocking the myosin binding site to which the myosin head can now bind
Describe the characteristics of slow and fast twitch muscles
Type I: Slow, Aerobic, High mitochondria, Slow rate of fatigue
Type IIa: Middle
Type IIb: Fast, Anaerobic, Low mitochondria, Rapid fatigue
Describe different types of physical performances and their energy sources
Power: stored ATP and phosphocreatine
Speed: non-oxidative breakdown of intramuscular glycogen
Endurance: aerobic metabolism
Breakdown of liver glycogen, lactate, and fatty acids
Explain the differences between eccrine and apocrine sweat glands
Eccrine:
Found across the majority of the body
Very important in temperature regulation
Has a duct and coiled gland which are covered by a vasculature network
Also is innervated by sympathetic nerve fibers that are cholinergic
Apocrine:
found in the axial and perineal regions
Can release pheromones
