Bio Chapter 9

_

• _ are the glial cells that form myelin sheaths in the cns. Oligodendrocytes

• _ neurons are neurons that have one axon and multiple dendrites. Most neurons in the brain and spinal cord belong to this category. multipolar

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• -55 mv is the _ potential of neurons if this potential is reached an action potential will occur. threshold

A

o Action potentials can only occur on: axons

o Axon terminals are located: at the ends of axons

o A synapse is usually found between an axon ending and a: cell body, dendrite

• A synaptic _ is a space between a synaptic knob and the receptive surface of another cell. Cleft

• A _ usually separates an axon and a dendrite or an axon and a cell ody of two separate neurons. Synapse

• An a or none respose means: stimuli of hreshold ntensity will generate identical action potentials

• A _ period is a brief time following a nerve impulse when the membrane is unresponsive to an ordinary stimulus.

C

o Cells of the nervous system include _ and _. Neuons, neuroglia

• Components of neural tissue include neual tissue include neurons blood vessels and connective tissue. neurogia

E

• Effectors are defined as: skeletal muscle, cardiac muscle, glands

G

o Gray matter is made up of: dendrites and cell bodies, unmyelinated axons

M

o Motor impulses stimulate muscles or glands also called _. effectors

N

o Nodes of ranvier are areas o exposed axon in between _ _. Myelin sheaths

• Neuroglial cells function to: send and receive messages, support and aid neurons protect neurons

• Neuons have processes called dendrites that receive signals from other neurons. Dendrites

• Near its end an axon may have fine extensions with an endings called axon _. Terminals

• Neurotransmitters binding to their receptors in the postsynaptic cell will: sometimes open ion channels sometimes close them

• Neurotransmitter molecues diffuse across the synaptic cleft and bind to _ in the postsynaptic neuron membrane. receptors

P

o Place in order the...