Bio Chap 5 – Flashcards

10. Proliferation is the: a. formation of dendrites and an axon. b. insulation process that occurs on some axons. c. production of new cells d. movement of primitive neurons and glia.

11. After the migrating neuron reaches its destination, ________ begin to form. a. nuclei b. ganglions c. dendrites d. axons •

12. In humans, myelination first occurs in the: a. midbrain. b. forebrain. c. spinal cord. d. hindbrain. •

13. When Sperry cut a newt's optic nerve and rotated the eye by 180 degrees, each axon: a. regenerated to the area where it had originally been. b. regenerated, but to the area appropriate to its new location. c. degenerated. d. regenerated to a random location.

14. Axons sort themselves over the surface of the target area: a. through necrosis. b. based on their size. c. by following a gradient of chemicals. d. through apoptosis. •

15. Competition of neurons for postsynaptic sites results in survival of only the most successful axons. This general principle is called: a. apoptosis. b. neural Darwinism. c. natural selection. d. evolution. •

16. ________ steer new axonal branches and synapses in the right direction. a. Glia b. Neurotrophins c. Chemokines d. Immunoglobulin

17. The function of neurotrophins is to: a. be used as fuel. b. signal that an axon has been "rejected." c. inhibit proliferation. d. promote survival of axons. •

18. In infants, anesthetic drugs can increase: a. myelination. b. apoptosis. c. proliferation. d. migration. •

19. What brain abnormalities are found in children with fetal alcohol syndrome? a. lack of dopamine receptors b. smaller than normal ventricles c. short axons with few branches d. short dendrites with few branches •

20. Children of mothers who use cocaine during pregnancy: a. have a slightly lower IQ score. b. are born with severe abnormalities resembling cerebral palsy. c. have a slightly higher birth weight. d. are likely to develop Turner's syndrom

21. Which of the following factors seems to be particularly important for branching of neurons during brain development? a. Having good teachers b. Having a sterile environment c. Physical activity d. Playing logic games •

22. Which of the following is the most common cause of a stroke? a. Hemorrhage of an artery b. Blow to the head c. Lack of glucose d. Ischemia from an obstruction of an artery •

23. Ischemia is to ________ as hemorrhage is to ________. a. obstruction; rupture b. barely noticeable; lethal c. older individuals; younger individuals d. proximal; distal

24. Which of the following treatments would be most likely to help a patient starting several days after a stroke? a. Extensive bed rest b. Giving stimulant drugs combined with physical therapy c. Injecting a drug to block dopamine d. Administering tranquilizers •

25. What is the term for the new branches that may form in uninjured axons after damage to surrounding axons? a. denervation supersensitivity b. diaschisis c. collateral sprouts d. bifurcations •

26. ________ helps compensate for decreased axon input. a. Enervation supersensitivity b. Denervation supersensitivity c. Axon supersensitivity d. Disuse supersensitivity

27. A continuing sensation of an amputated body part is called: a. Neuralgia. b. tingling limb. c. phantom limb. d. ghost limb. •

28. Sensations from phantom limbs: a. do not have a neural basis. b. can be diminished if more of the limb is removed surgically. c. come from the stump of the amputated limb. d. are a result of brain reorganization.