By which term is a muscle that opposes or reverses a particular movement called?
1.fixator
2.synergist
3.agonist
4.antagonist
During muscle cell contraction, what happens because of Ca ++ binding to troponin?
1.ATP hydrolyses to ADP.
2.The binding site on actin is uncovered.
3.Acetylcholine (ACh) is released.
4.The cross-bridge disengages from the thin filament.
One of the following is NOT a function of testosterone, which one?
1.Maintains glands of the reproductive tract.
2.Stimulates anterior pituitary to release FSH and LH.
3.Maintains secondary sex characteristics.
4.Stimulates spermiogenesis.
Smooth muscle cells may be described by which of the following?
1.striated, involuntary, uninucleate
2.not striated, voluntary, multinucleate
3.not striated, involuntary, uninucleate
4.striated, voluntary, multinucleate
What causes the myosin binding site of an actin molecule to be exposed?
1.calcium ions attaching to troponin
2.ATP attaching to the myosin cross-bridge
3.a nerve impulse reaching the motor end plate of a motor nerve
4.acetylcholine crossing the neuromuscular junction
Which is the largest of the structures in a muscle fi bre?
1.myofilament
2.myopic
3.myofibril
4.myosin
Which of the following muscles is a common intra-muscular injection site?
1.deltoid
2.vastus medialis
3.gluteus maximus
4.latissimus dorsi
Which of the following muscles is NOT named after its location in the body?
1.fl exor carpi radialis
2.rectus abdominus
3.sternocleidomastoid
4.biceps brachii
Which one of the following is NOT a characteristic of skeletal muscle?
1.contractility
2.autonomic innervation
3.excitability
4.extensibility
Which protein(s) are found in thin myofi laments?
1.actin, tropomyosin, and troponin
2.actin and tropomyosin
3.actin
4.actin, myosin, tropomyosin and troponin