Nervous System

Question 1

central nervous system

Answer 1

part of the nervous system made up of the brain and spinal cord

Question 2

sensory (afferent) division

Answer 2

part of the nervous system made up of nerves outside the CNS

Question 3

peripheral nervous system

Answer 3

division of the PNS composed of nerves that carry information TO the CNS

Question 4

motor (efferent) division

Answer 4

division of the PNS composed of nerves that carry information FROM the CNS

Question 5

Endomysium

Answer 5

connective tissue that surrounds each muscle fiber

Question 6

Perimysium

Answer 6

connective tissue that surrounds the each fascicle

Question 7

epimysium

Answer 7

connective tissue that surrounds the entire muscle

Question 8

dendrites

Answer 8

fibers that receive and convey messages to the cell body of a neuron

Question 9

cell body

Answer 9

the metabolic center of a neuron; contains the nucleus

Question 10

axon

Answer 10

neuron fibers that conduct impulses away from the cell body

Question 11

myelin

Answer 11

white, fatty material found in neuron coverings

Question 12

myelin sheath

Answer 12

covering composed of Schwann cells that insulates the rate of transmission

Question 13

Schwann cell

Answer 13

cells that are wrapped around axons; produce myelin

Question 14

node of Ranvier

Answer 14

gaps along the axon that are not covered by myelin sheath; impulses jump from node to node

Question 15

axon terminal

Answer 15

branches at the end of and axon that contain vesicles of neurotransmitters

Question 16

synapse

Answer 16

the space between an axon terminal and the membrane of the next cell

Question 17

white matter

Answer 17

bundles of myelinated axons in the brain and spinal cord

Question 18

gray matter

Answer 18

unmyelinated and tightly-packed neuron cell bodies

Question 19

sensory neuron

Answer 19

type of neuron that carries impulses from the receptors to the CNS

Question 20

interneuron

Answer 20

type of neuron that connects sensory and motor neurons in the CNS

Question 21

motor neuron

Answer 21

type of neuron that carries impulses from the CNS to a muscle or gland

Question 22

proprioceptors

Answer 22

sensory receptors in muscles and tendons that detect stretch or tension in skeletal muscles, tendons, and joints; maintain balance and posture

Question 23

irritability

Answer 23

functional property of a neuron that enables it to respond to a stimulus and convert it to a nerve impulse

Question 24

conductivity

Answer 24

functional property of a neuron that enables it to transmit an impulse to other neurons, muscles, or glands

Question 25

resting potential

Answer 25

the charge on a nerve cell membrane at rest that gives it the potential to react to a stimulus

Question 26

polarized

Answer 26

the difference in charge across a nerve cell due to presence of fewer positive ions along the inside of the membrane than along the outside of the membrane

Question 27

depolarization

Answer 27

occurs when a stimulus temporarily changes the permeability of the neuron membrane and sodium ions rush into the cell; membrane polarity is changed.

Question 28

action potential

Answer 28

if the stimulus is strong enough to cause a large influx of sodium ions the depolarization will activate a nerve impulse or action potential

Question 29

all-or-none response

Answer 29

an action potential will travel along the entire length of the neuron or it doesn’t happen at all; there is no partial response.

Question 30

repolarization

Answer 30

the restoration of the negative charge on the inside of the membrane that occurs immediately after an action potential; membrane becomes impermeable to Na+ ions and K+ ions diffuse out.

Question 31

sodium-potassium pump

Answer 31

membrane channel that uses ATP to actively transport Na+ and K+ ions to the original ionic state of the resting potential.

Question 32

cerebral cortex

Answer 32

outermost layer of the cerebrum composed of gray matter; responsible for thinking and processing information from the five senses.

Question 33

frontal lobe

Answer 33

the most anterior section of the cerebrum; involved in motor function, problem-solving, memory, language, etc.

Question 34

parietal lobe

Answer 34

section of the cerebrum over the parietal bone; processes sensory information such as touch, temperature, and taste.

Question 35

temporal lobe

Answer 35

section of the cerebrum over the temporal bone, inferior to frontal and parietal lobes; responsible for auditory and olfactory perception.

Question 36

corpus callosum

Answer 36

large fiber tract that connects the two cerebral hemispheres; and allows communication between the two sides of the cerebral cortex.

Question 37

meninges

Answer 37

protective connective tissue membranes around the brain and spinal cord; dura mater, arachnoid mater, and pia mater.

Question 38

cerebrospinal fluid

Answer 38

fluid formed from plasma in brain cavities called ventricles; provides a watery cushion for the CNS

Question 39

blood-brain barrier

Answer 39

Physical barrier formed by very impermeable capillaries in the brain; protects neurons from blood-borne substances.

Question 40

fascicle

Answer 40

bundle of nerve cells (or muscle cells)

Question 41

neurotransmitters

Answer 41

chemicals released from vesicles at the axon terminal that diffuse across the synapse to carry the nerve cell.