neurobiology module 1

Astrocytes

remove excess neurotransmitter at synapses; help form the blood brain barrier.

microglia

survey enviroment in CNS and mediate inflammation

oligodendrocytes

myelinates axons in the central nervous system.

Ependymal cells

Found in the choroid plexus where they produce cerebrospinal fluid

schwann cells

myelinates axons in the peripheral nervous system

satellite cells

insulate sensory cell bodies in dorsal

Identify the area of a neuron where action potentials are generated

Inhibitory postsynaptic potentials are graded potentionals that occur along dendrites/ cells body as a result of _____ influx

Cl-

during depolarization, which ion moves the neuron?

Na+

During repolarization, which ion moves OUT of the neuron

K+

The all or none principle means?

An action potential only occurs if threshold is reached

which of the following is true of schwann cells

They are important in nerve regeneration.

which of the following is true of oligodendrocytes

they form myelin in the CNS

saltatory conduction occurs in:

myelinated axons

Myelin increases conduction speed primarily because it:

prevents current from leaking across membrane as much

electrical synapses differ from chemical synapses because electrical synapses:

Use gap junction connections

at most chemical synapses, the presynaptic electrical signal becomes a:

chemical signaling

which ion enters presynaptic terminal and triggers vesicle fusion?

Ca2+

an excitatory postsynaptic potentional is most closely associated with:

Na+ influx and depolarization

what is the approximate resting membrane potential of most neurons?

-70mV

what threshold value was emphasized in your slides for triggering an action potential

-55mV

name the two glial cells from myelin

oliodendrocytes and schwann cells

Briefly explain the difference between graded potentials and action potentials.

Graded potentials are small, local, variable changes in membrane potential that can decay over distance. action potentias are all-or-nothing signals that begin once threshold is reached and travel down the axon without fading.