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1. muscle fiber an individual muscle cell
2. fasicle a group of muscle cells within the belly of a muscle
3. sarcolemma plasma membrane of skeletal muscle cells
4. sarcoplasm the cytoplasm of a skeletal muscle cell
5. sarcomere Contractile unit of a muscle cell that make a myofibirl
6. sarcoplasmic reticulum Modified endoplasmic reticulum that regulates cal-
cium in the cell
7. T (transverse) tubules Tubes continuous with the sarcolemma to increase
surface area
8. myofibril The major component of a muscle cell (takes up the
most intracellular volume)
9. myoglobin Oxygen-binding protein in a muscle cell
10. multi nucleate Containing many nuclei
11. epimysium Fibrous connective tissue that is continuous with the
tendon
12. Which type of muscle cell(s) is (are) skeletal, cardiac
striated? Choose all that apply.
13. Skeletal muscle tends to contain False, Skeletal muscle cells tend to be very long and
short, branched cells. T or F? cylindrical.
14. The neuromuscular junction (or neuron:skeletal muscle
synapse) involves with of the follow-
ing two cell types?
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15. Which of the following neurotrans- acetylcholine
mitters are released at the neuromus-
cular junction?
16. What type of channels bind to acetyl- chemical (ligand)-gated, (Acetylcholine is a chemical
choline in the post-synaptic (muscle and it provides the "key" to open channels in the
cell) membrane? muscle cell membrane.)
17. Receptors for acetylcholine are locat- True, By definition, the motor end plate is the part of
ed in the motor end plate of the mus- the muscle cell membrane that forms a synapse with
cle cell. the somatic motor neuron.
T or F?
18. What is the major role of acetyl- To break down acetylcholine in the synaptic cleft.
choline esterase? (Acetylcholine esterase enzymatically breaks down
acetylcholine from the cleft to STOP the signal from
the motor neuron. This is an important step that
leads to muscle relaxation.)
19. Transverse tubules are extensions of sarcolemma
which of the following organelles?
20. If calcium protein channels in the sar- False, Calcium concentrations are high in the sar-
coplasmic reticulum (SR) open in re- coplasmic reticulum (due to calcium pumps). If pro-
sponse to an action potential, calcium tein channels are opened (like what occurs during
diffuses out of the sarcoplasm and an action potential of a skeletal muscle cell), the
into the SR. calcium will diffuse into the sarcoplasm.
T or F?
21. Which of the following protein in- Actin, Myosin
teract during a "cross-bridge" forma-
tion? Please choose all that apply.
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