Which statement about skeletal muscles is true?
A) In a muscle fiber at rest, calcium is higher in the sarcoplasm than in the sarcoplasmic reticulum.
B) The dihydropyridine (DHP) receptor is insensitive to action potentials.
C) Calcium triggers the interaction of actin and myosin and the sliding of filaments.
D) DHP and ryanodine receptors have a physical gap between them when they are functioning in a skeletal muscle contraction.
E) The ryanodine receptor is located in the T tubule membrane.

Question

Quizplus · Accepted Answer

Calcium triggers the interaction of actin and myosin and the sliding of filaments, leading to muscle contraction. In a muscle fiber at rest, calcium is actually higher in the sarcoplasmic reticulum than in the sarcoplasm, waiting to be released upon the appropriate signal. The dihydropyridine (DHP) receptor is actually sensitive to action potentials, and interacts with the ryanodine receptor to release calcium from the sarcoplasmic reticulum. There is no physical gap between the DHP and ryanodine receptors when they are functioning in a skeletal muscle contraction. The ryanodine receptor is actually located in the sarcoplasmic reticulum membrane.

Which Statement About Skeletal Muscles Is True