Nervous System Vocabulary**

Question 0

Sheath formed from schwann cells on the exterior of some axons

Answer 0

Neurilemma

Question 1

Depolarization and repolarization along an axon

Answer 1

Nerve impulse

Question 2

Nerve cells

Answer 2

Neurons

Question 3

Chemicals that axons secrete on the effectors

Answer 3

Neurotransmitters

Question 4

Specialized cells of the nervous system that support, nourish, and protect neurons

Answer 4

Neuroglial cells

Question 5

A neuron that transmits impulses from the CNS to the effector

Answer 5

Motor neuron

Question 6

Fatty layers formed from certain neuroglia that surround axons, providing insulation

Answer 6

Myelin sheath

Question 7

An electrical charge on a cell membrane surface due to an unequal distribution of positive and negative ions on either side of the membrane

Answer 7

Polarized

Question 8

The difference in electrical charge between the inside and the outside of an undisturbed nerve cell membrane

Answer 8

Resting potential

Question 9

A type of neuroglial cell that surrounds an axon of a peripheral neuron, forming the neurilemma sheath and myelin

Answer 9

Schwann cell

Question 10

The space between 2 cells forming a synapse

Answer 10

Synaptic cleft

Question 11

Neurons that transmit impulses from receptors to the CNS

Answer 11

Sensory neurons

Question 12

Process that requires energy to move a substance across a cell membrane, usually against the concentration gradient

Answer 12

Active transport

Question 13

The sequence of electrical changes that occurs in a portion of a nerve cell membrane that is exposed to a stimulus that exceeds the membrane’s threshold

Answer 13

Action potential

Question 14

A nerve fiber that conducts an impulse away from the neuron cell body

Answer 14

Axon

Question 15

A type of neurotransmitter which is a biochemical secreted at axon ends of many neurons; transmits nerve messages across synapses

Answer 15

Acetylcholine

Question 16

Portion of nerve cell that included a cytoplasmic mass and a nucleus, and from which nerve fibers extend

Answer 16

Cell body

Question 17

Process of a neuron that receives input from other neurons

Answer 17

Dendrites

Question 18

The loss of an electrical charge on the surface of a cell membrane

Answer 18

Depolarized

Question 19

A neuron between a sensory neuron and a motor neuron

Answer 19

Interneuron

Question 20

Simulation level that must be exceeded to elicit a nerve impulse

Answer 20

Threshold

Question 22

Membranous cytoplasmic sacs formed by infoldings of the cell membrane

Answer 22

Vesicle

Question 23

Space between Schwann cells

Answer 23

Nodes of Ranvier

Question 24

A change or signal in the environment that helps nerves to react in some way

Answer 24

Stimulus

Question 25

The restoration of a polarized state across a membrane.

Answer 25

Repolarization

Question 26

A mechanism of active transport that moves potassium ions into and sodium ions out of a cell.

Answer 26

Sodium-potassium pump

Question 27

a filtering mechanism of the capillaries that carry blood to the brain and spinal cord tissue, blocking the passage of certain substances.

Answer 27

Blood-brain barrier

Question 28

The spreading of something

Answer 28

Propagation

Question 29

a neuron conducting impulses outwards from the brain or spinal cord

Answer 29

Efferent neurons

Question 30

a neuron conducting impulses inwards to the brain or spinal cord

Answer 30

Afferent neurons

Question 31

A small mass of differentiated tissue

Answer 31

Node

Question 32

Ends of the axon that release neurotransmitters

Answer 32

Axon terminal

Question 33

a period immediately following stimulation during which a nerve or muscle is unresponsive to further stimulation.

Answer 33

Refractory Period

Question 34

The potential difference between the region inside the membrane and the region outside the membrane

Answer 34

Resting potential

Question 35

Neurons are depolarized sufficiently

Answer 35

Threshold potential