Page 328 - Atlas of Histology with Functional Correlations
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muscles. The T tubules in cardiac muscles are less well developed, and for
proper muscular contraction, some calcium must be imported from outside
of the cell into the sarcoplasm.
2. Correct Answer: C. In cardiac muscles, calcium ions enter the sarcomere
from outside of the muscle fibers and from the sarcoplasmic reticulum,
which is less well developed than in the skeletal muscle.
3. Correct Answer: A. Z lines in the striated muscles. The dense bodies
contain similar proteins found in the Z lines of striated muscles.
4. Correct Answer: E. Cell membrane. The caveolae appear to have similar
functions to those of the T tubules in striated muscles.
5. Correct Answer: C. Caveolae in smooth muscle control the influx of
calcium into the smooth muscle fibers in a way that is similar to the T
tubules of striated muscles.
ADDITIONAL HISTOLOGIC IMAGES
FIGURE 8.18 ■ Cross and longitudinal section of skeletal muscle fibers from a
primate tongue. Stain: Mallory-Azan. ×70.
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