Nerve Terms

Question 1

central nervous system (CNS)

Answer 1

consists of brain and spinal cord; processes and responds to all messages from PNS

Question 2

spinal cord

Answer 2

bundle of nerves; extension of brain stem

Question 3

peripheral nervous system (PNS)

Answer 3

allows the brain and spinal cord to receive and send info to other areas of the body which allows us to react to stimuli in our invironment

Question 4

sensory division

Answer 4

made up of afferent neurons that conduct impulses to the CNS from receptors that detect changes inside and outside the body; these include receptors for touch, smell, taste, hearing, sight, pain, body position (proprioception) ad receptors in the viscera (internal organs) that indicate bladder fullness, stomach aches, blood pressure and more

Question 5

motor division

Answer 5

made up of efferent neurons that conduct impulses away from the CNS to the muscles and glands, allowing the brain to control heart rate, blood pressure, breathing rate, sweat production, and hormone release, among other functions

Question 6

somatic nervous system

Answer 6

responsible for voluntary movement of muscles and the process known as a reflex arc, a system that carries nerve impulses back and forth between the CNS and the skeletal muscles, skin, and sensory organs

Question 7

autonomic nervous system

Answer 7

responsible for involuntary functions inside the body; communicates with internal organs and glands to regulate body processes that take place without conscious effort including heartbeat, pupil dilation, blood flow, breathing, and digestion

Question 8

sympathetic nervous system

Answer 8

regulates flight-or-fight responses; preforms tasks including relaxing the bladder, speeding up heart rate, slowing digestion, and dilating pupils

Question 9

parasympathetic nervous system

Answer 9

helps maintain normal body functions and conserves physical resources; performs tasks including controlling the bladder, slowing down heart rate, normalizing digestion, and constricting pupils

Question 10

glial cells

Answer 10

neuron partner; surround and protect neurons; provide immune defense by destroying pathogens; remove dead neurons; help form myelin sheaths, regulate ions

Question 11

neuron

Answer 11

electrically excitable cell that transmits info throughout the nervous system through electrical and chemical signals

Question 12

interneurons

Answer 12

these are found only in the CNS and transmit messages between the CNS and the sensory and motor neurons of the PNS

Question 13

nerve

Answer 13

collection of neuron fibers (axons) bundles with blood vessels and connective tissue; carry impulses between the CNS and other parts of the body; most have axons of both sensory and motor neurons

Question 14

axon

Answer 14

long threadlike part of a neuron that sends impulses to other cells

Question 15

dendrite

Answer 15

short branched extension of neuron that receives impulses from other cells at synapses

Question 16

synapse

Answer 16

site of transmission of electric nerve impulses between two neurons or between a neuron and a gland or muscle cell

Question 17

neurotransmitter

Answer 17

chemical substance that is releases at the end of a nerve fiber by the arrival of a nerve impulse and transfers the impulse to another neuron, gland, or muscle cell

Question 18

action potential

Answer 18

the brief (~1/1000 of a second) reversal of electric polarization of the membrane of a neuron or muscle cell; in the neuron it produces the nerve impulse; in the muscle cell it produce the contraction required for movement

Question 19

myelin sheath

Answer 19

fatty white substance that forms protective coating around axons in the CNS; insulates and protects and helps speed transmission of nerve impulses

Question 20

reflex arc

Answer 20

results when sensory neurons activate spinal motor neurons which activate muscles cells before routing signals through the brain for analysis

Question 21

PNS branches

Answer 21

sensory and motor divisions

Question 22

motor division branches

Answer 22

somatic and autonomic nervous systems

Question 23

autonomic nervous system branches

Answer 23

sympathetic and parasympathetic nervous systems

Question 24

synaptic terminal

Answer 24

the location where axons terminate at they synapse of transmission of info by the release of a chemical transmitter

Question 25

brain stem

Answer 25

nerve connection of motor and sensory systems from the rest of the body pass through this; includes midbrain, pons, and medulla oblongata