1) many medications introduced into the bloodstream cannot directly affect the neurons
of the cns because
a) oligodendrocytes form a continuous myelin sheath around the axons.
b) the endothelium of cns capillaries forms a blood-brain barrier.
c) the neurolemma is impermeable to most molecules.
d) ependymal cells restrict the flow of interstitial fluid between the capillaries and the
neurons.
e) astrocytes form a capsule around neurons.
2) movements unique to the large intestine are ________ movements.
a) peristaltic
b) segmentation
c) mass
d) pendular
e) writhing
3) the waste product bilirubin is produced from
a) globin chains of hemoglobin.
b) heme molecules plus iron.
c) heme molecules lacking iron.
d) iron found in hemoglobin molecules.
e) abnormal proteins found in red blood cells.
4) the auditory tubes open into the
a) nasopharynx.
b) oropharynx.
c) laryngopharynx.
d) larynx.
e) nasal cavity.
5) various types of macrophages are derived from
a) lymphocytes.
b) monocytes.