1) where is dystrophin, the protein that is defective in muscular dystrophy, normally
found?
a. between the outermost myofilaments and the sarcolemma of a muscle fiber
b. as a transmembrane protein of the sarcolemma
c. in the z discs of skeletal and cardiac muscle
d. in the dense bodies of smooth muscle
e. bridging the gap between the sarcolemma and synaptic knob
2) we live in an ever-changing environment outside of our body, yet our internal
conditions remain relatively stable. this is called __________.
a. homeostasis
b. metastasis
c. responsiveness
d. adaptation
e. evolution
3) what happens when acetylcholine stimulates its receptors in the neuromuscular
junction?
a. the release of ca2+ from the sarcoplasmic reticulum decreases.
b. the permeability of the sarcolemma to na+ increases.
c. the positive charge on the sarcolemma decreases.
d. the threshold of the muscle fiber lowers.
e. the inhibitory effect of acetylcholinesterase is overridden.
4) heart rate, blood pressure, and respiratory rate peak during the __________.
a. excitement phase
b. erection of the penis
c. climax (orgasm)
d. plateau phase
e. resolution phase