The "tanning" effect (darkening of the skin) that occurs when a person is exposed to the sun is due to the increased presence of ________
A) melanin
B) keratin
C) oil
D) epidermis dendritic cells
E) sweat
Anser: A) melanin (due to the pigment: increased production of melanin that helps to block ultraviolet lights.)
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Ventricular systole includes the periods of
a. isometric contraction and ventricular ejection. b. isovolumetric contraction and ventricular ejection. c. isometric contraction and end-systolic volume. d. isovolumetric contraction and end-systolic volume. e. none of these
The effectiveness of positive-pressure ventilations when treating a head-injured patient can ONLY be determined by:
A. immediate reassessment following the intervention. B. a neurosurgeon or emergency department physician. C. reassessing the patient's blood pressure after at least 10 minutes. D. noting a decrease in the heart rate during ventilations.
Collectively, reactions that build new molecules are known as
A) anabolic. B) metabolic. C) synthetic reactions. D) exchange reactions. E) catabolic.
Hormones called ________ are involved in regulation of white blood cell populations.
Fill in the blank(s) with the appropriate word(s).