Tetanic muscle contractions don't occur in a normal cardiac muscle because
A) cardiac muscle tissue contracts on its own.
B) neural stimulation is lacking.
C) the refractory period lasts until the muscle relaxes.
D) the refractory period ends before the muscle reaches peak tension.
E) potassium channels outnumber sodium channels.
Answer: C
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A rounded articular projection supported on a constricted portion (neck) of a bone is called a
a) foramen. b) condyle. c) tuberosity. d) head. e) trochanter.
The sense of hearing is provided by receptors of the
A) outer ear. B) middle ear. C) internal ear. D) pinna. E) semicircular canals.
The discipline that studies the functions of the nervous system, including the way that impulses are conducted, is known as ________.
Fill in the blank(s) with the appropriate word(s).
Which of the choices below best describes the autonomic mechanism for regulating GFR?
a) Sympathetic fibers initiate the myogenic response to decrease the GFR. b) Sympathetic fibers override local controls to decrease the GFR. c) Sympathetic fibers trigger release of an enzyme to decrease the GFR. d) Sympathetic fibers trigger the release of hormones from the heart.