Nervous System

Question 1

central nervous system

Answer 1

brain
spinal cord: tube of nerves that connects brain to body
all messages to/from brain go thru spinal cord

Question 2

peripheral nervous system

Answer 2

network of nerves that connects CNS to other parts of body
has sensory neurons

Question 3

sensory neurons

Answer 3

carry info from sensory receptors in body to spinal chord to brain

Question 4

motor neurons

Answer 4

neurons that carry info from brain to spinal chord to muscles and glands

Question 5

interneurons

Answer 5

neurons that act as middle man between sensory and motor n

Question 6

pns: somatic nervous system

Answer 6

controls voluntary movemebnt of body’s skeletal muscles

Question 7

pns: autonomic nervous system

Answer 7

controls glands/internal organs
heartbeat/digestion
release of hormones into bloodstream

Question 8

pns: ans: sympathetic nervous system

Answer 8

arouses body to mobilze in stressful situations
ex: inc blood pressure, accel. heartbeat,
FIGHT or FIGHT (or FREEZE)

Question 9

pns: ans: parasympathetic nervous system

Answer 9

calms body and conserves energy after stressful situations
ex: reduces heart rate, dec. blood pressure
body back to HOMEOSTASIS

Question 10

spinal reflexes

Answer 10

simple, automatic response by nerves in spinal cord. don’t need instructions from brain

Question 11

reflex arc

Answer 11

single sensory neuron and motor neuron that communicate thru interneuron
ex: knee-jerk reflex, hand on hot stove

Question 12

neuron

Answer 12

nerve cell in brain that transmit info
85-100 billi in brain

Question 13

neural network

Answer 13

when neurons connect with thousands of other

Question 14

dendrites

Answer 14

neuron’s bushy branching extensions that receive/interate messages from other neurons
passes message to cell body that contain nucleus
grow new dendrites to form more connections - learning

Question 15

axon

Answer 15

neuron extension that passes messages thru branches to other neurons/muscles/glands
conducts action potentials

Question 16

myelin sheath

Answer 16

fatty tissue that surrounds and protects the axon and speeds up electrical impulses
multiple sclerosis is caused by ms degredation

Question 17

glial cells

Answer 17

form myelin sheath
structure, insulation, nutrition, waste transport, and protection for neurons

Question 18

action potential

Answer 18

firing of neuron
brief electrical impulse that travels down axon
threshold not met, no ap triggered

Question 19

all or nothing principle

Answer 19

ap either fires or doesn’t
no strong or weak

Question 20

threshold

Answer 20

specific charge that must be reached inside of the axon before neuron can fire action potential
54 millivolts

Question 21

refractory period

Answer 21

recovery period after action potential
1-2 ms
neuron can’t fire until period is over

Question 22

resting potential

Answer 22

electrical potential difference when the cell is in a non-excited state

Question 23

synapse

Answer 23

small gap between the axon of one neuron and dendrite of another
neurotransmitters cross this gap and attach to receptors on the neighboring neuron

Question 24

neurotransmitter

Answer 24

chemical messenger that sends messages between neurons

Question 25

reuptake

Answer 25

when neighboring neuron gets message, neurotransmitters are reabsorbed back into axon of sending neuron

Question 26

receptors

Answer 26

area on dendrite where neurotransmitters attach and transmit their message