Nervous System Vocabulary

Front 1

Stimulus (Plural: Stimuli)

Back 1

any internal or external change that causes a response

Front 2

Response

Back 2

a reaction to stimuli

Front 3

Central Nervous System (CNS)

Back 3

made up of brain and spinal cord

Front 4

Peripheral Nervous System (PNS)

Back 4

made up of all other nerves that radiate from the spinal cord to parts of the body

Front 5

Brain

Back 5

receives input brought from spinal cord and peripheral nerves, processes it, and then sends a signal back out

- The brain is an organ
- It controls inner organs (heart beat, breathing and digestion)
- It controls basic chemical and thermal balance of the body (sleep, hunger, thirst, reproduction)
- It controls learning, thinking, memory, emotions
- It controls motor skills (riding bicycles, writing, dancing, balancing on one foot)

Front 6

Spinal Cord

Back 6

receives a signal from peripheral nerves and sends the signal to the brain or other peripheral nerves

Front 7

Peripheral Nerves

Back 7

receive stimulus from external or internal environment. Signal is taken to brain and/or spinal cord

Front 8

Neuron

Back 8

a nerve cell that generates and transmits messages (as chemical and electrical signals) to different parts of the body)
**Made up of cell body, dendrites, axon, myelin sheath, axon terminal, neurotransmitter

Front 9

Axon

Back 9

Function: transmit the electrical signal from the cell body to axon terminals
Structure: long, covered by myelin sheath

Front 10

Dendrite

Back 10

Structure: finger-like projections from the cell body
Function: receives impulse from previous neurons

Front 11

Cell Body

Back 11

Structure: eukaryotic animal cell, has all organelles present and a plasma membrane
Function: receives chemical signals from synapse and converts it to an electrical signal

Front 12

Myelin Sheath

Back 12

Function: increases the speed of electrical signal

Front 13

Axon Terminals

Back 13

Function: receives electrical signal from axon and releases neurotransmitters (chemical signal) into the synapse

Front 14

Synapse (Synaptic Space)

Back 14

- The space between axon terminals of one neuron and dendrites of the next neuron
- Neurotransmitters move across this space

Front 15

Neurotransmitter

Back 15

- Chemicals (proteins) made in the cell body of neurons and released from axon terminals
- Carry signals from one neuron to another neuron

Front 16

Nerve Impulse

Back 16

an electrical current that runs down the length of an axon. It starts at the beginning of the axon and ends at the axon terminals

Front 17

Reflex

Back 17

rapid, predictable and involuntary responses to stimuli

Front 18

Reflex Arc

Back 18

direct rout from a sensory neuron, to an interneuron, to a motor neuron
**ONLY UNCONSCIOUS MOVEMENTS

Front 19

Motor Neuron

Back 19

carry impulses from the CNS to the effectors -- organs, muscles or glands

Front 20

Interneuron

Back 20

contained within the CNS and relays messages between sensory and motor neurons (processes input from sensory neuron and creates a reaction)

Front 21

Sensory Neuron

Back 21

carry impulses from the sensory receptors to the CNS