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