The autorhythmicity of cardiac pacemaker cells is made possible by the reduced permeability of _______.
A) sodium
B) magnesium
C) calcium
D) potassium
Ans: D) potassium
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What does the central nervous system use to determine the strength of a stimulus?
A) size of action potentials B) origin of the stimulus C) type of stimulus receptor D) frequency of action potentials
New growth of blood vessels is called _____________
a. encapsulation b. angiogenesis c. oncogenesis d. carcinogenesis
Which is TRUE about hormonal control during pregnancy?
A. The placenta responds to estrogen and progesterone from the corpus luteum, but does not secrete them. B. The corpus luteum must remain functional for 38 weeks because it is the main source of estrogen and progesterone. C. The placenta is provided with androgens by the maternal ovaries and adrenal glands, and by the fetal adrenal glands. D. The placenta produces estrogen without any contribution from the fetal adrenal cortex. E. The placenta secretes only steroid hormones, while fetal and maternal pituitary glands secrete pregnancy-specific protein hormones.
During long-term starvation,
A) Glycogen stores become depleted. B) Skeletal muscle experiences protein degradation. C) Fatty acids and amino acids are converted into ketone bodies. D) All of the above