Which best describes a role of L-type Ca2+ channels in cardiac muscle cells?
A. They function exactly the same in cardiac muscle cells as they do in skeletal muscle.
B. They are directly responsible for making cardiac muscle fatigue-resistant.
C. They are responsible for preventing tetanic contractions.
D. They cause the absolute refractory period to be very brief.
E. They act as non-conducting voltage sensors that mediate excitation-contraction coupling.
C
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The technical term for the forearm is __________.
Fill in the blank(s) with the appropriate word(s).
The incus, malleus, and stapes of the middle ear
A. are part of the vestibular apparatus. B. are found inside the cochlear duct. C. serve to amplify the pressure of sound vibrations from the air in the outer ear to the fluid in the inner ear. D. serve to keep the pressure on the two sides of the tympanic membrane equal. E. are in direct contact with both the tympanic membrane and the round window.
During both mandibular protrusion and retrusion, the rotation of the articulating surface of the mandible against the disc in the lower synovial cavity of the TMJ is restricted by the
A. facial muscles. B. infrahyoid muscles. C. muscles of mastication. D. ligaments of the temporomandibular joint.
Hypocalcemia can cause ________
A) muscle weakness B) muscle spasms C) sluggish reflexes D) emotional disturbances E) depression of the nervous system