questions/answers
Closed head injury is ____. - the most common cause of brain damage in young adults
Closed head injury results in damage partially because of ____. - rotational forces that
push the brain against the inside of the skull
Which event is the most common cause of a stroke? - ischemia from an obstruction of
an artery
Ischemia is to ____ as hemorrhage is to ____. - obstruction; rupture
____ cells proliferate after a stroke. - Microglia
Damage due to stroke caused by ischemia can be minimized by administering a drug
that ____. - breaks up blood clots
Which treatment would be most likely to help a patient starting it several days after a
stroke? - giving stimulant drugs combined with physical therapy
What is one impediment to the regeneration of axons in the mammalian central nervous
system? - Glia releasing chemicals that inhibit axon growth
If some of the axons innervating a given cell are destroyed or if they become inactive,
what compensatory process takes place in the remaining presynaptic cells? - collateral
sprouting
After damage to a set of axons, neurotrophins induce nearby ____. - uninjured axons to
form new branches
Heightened sensitivity to a neurotransmitter after the destruction of an incoming axon is
known as ____. - denervation supersensitivity
If most of the axons that transmit dopamine to some brain area die or become inactive,
the remaining dopamine synapses become ____. - more responsive
After learning strengthens one set of synapses, other synapses ____. - weaken
A cortical cell originally responded to stimulation of the middle finger. After amputation
of that finger, it begins responding to the second and fourth fingers. Which action most
likely accounts for this? - synaptic reorganization