PSY 387 exam 1

water, oxygen, and _________ most freely flow across a cell membrane

carbon dioxide

The membrane of a neuron is composed of ____ with ____ embedded in them.

fat molecules; proteins

many dendrites contain short outgrowths called spines that

increase the surface area available for synapses

what an vertebrate animal contracts their flexor muscles of a leg, it relaxes the extensor muscle of the same leg. Sherrington considered this evidence for the existence of

inhibitory messages

What ordinarily prevents extensor muscles from contracting at the same time as flexor muscles?

inhibitory synapses in the spinal cord

a receptor can directly open a channel and thereby exert an ___________ effect, or it can produce slower but longer _________ effects

ionotropic; metabotropic

what do neurons have that other cells do not

large, branching extensions

which term refers to a chemical that binds to another chemical?

ligand

gaps in the insulating material that surrounds axons are known as

nodes of ranvier

_______________ in the brain and spinal cord and ___________ in the periphery are specialized types of glia that build myelin sheaths that surround neurons

oligodendrocytes; schwann cells

which process is more typical of a metatrophic effect than an ionotropic effect

producing long-lasting effects on the postsynaptic cell

the concentration gradient for potassium tends to

push k out of the cell

the effect of a neurotransmitter on a postsynaptic neuron is determined by the

receptors on the postsynaptic membrane

hormones exert their effects

similarly, to metabotropic neurotransmitters

the circuit for sensory neuron to muscle response is called

a reflex arc

the action potential of a neuron depends mostly on what movement of ions?

sodium ions entering the cell

what determines whether a neuron has an action potential

the combined effects of EPSPs and IPSPs

what causes an EPSP

the opening of Na channels

although slower than an AP, synaptic transmission is still relatively fast because

the synaptic cleft is very narrow

a drug that blocks the sodium gates of a neurons membrane will

block the action potential