Pulmonary surfactant begins to appear in the embryo around the
A. time of birth.
B. 28th week.
C. 18th week.
D. 8th week.
Answer: B
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Which of the following statements is NOT accurate with respect to erythrocytes?
A) They migrate into infected regions of tissue. B) They transport oxygen and carbon dioxide. C) They lack mitochondria. D) They lack nuclei. E) They contain large amounts of hemoglobin.
A syndesmosis is an example of which type of joint?
a. synarthrosis b. amphiarthrosis c. diarthrosis d. gomphosis
What is the importance of reciprocal innervation in muscular reflexes?
A. It prevents simultaneous activity of antagonistic muscle groups that would impede limb movement. B. It ensures that limbs on the contralateral side of the body perform the same movements as those on the ipsilateral side. C. It maintains signaling along afferent neurons from stretch receptors, even when a muscle shortens rapidly. D. It prevents excessive force on a muscle from resulting in tearing of fibers, or damage to the tendon. E. It recruits synergistic muscles to come to the aid of a muscle that help it generate force and limb motion.
__________-gated ion channels open or close when a molecule such as a hormone or neurotransmitter binds to them.
Fill in the blank(s) with the appropriate word(s).