action potential

Question 2

axon

Answer 2

Portion of a neuron; thin elongated structure emanating from the cell body, conductor of electrical impulses over distances between neurons, usually ends in synaptic terminal filled with neurotransmitter.

Question 3

axon hillock

Answer 3

In many neurons, the location where action potentials start.

Question 4

depolarization

Answer 4

Condition in which the membrane potential becomes more positive.

Question 5

electrochemical gradient

Answer 5

Difference in concentration of ions across a membrane maintained by energy activated proton pump cotransporters.

Question 6

electromyography

Answer 6

Measure of electrical activity in muscles.

Question 7

electrophysiology

Answer 7

Study of the electrical properties of cells and membranes.

Question 8

graded potential

Answer 8

Small change in membrane potential.

Question 9

hyperpolarization

Answer 9

Condition in which the membrane potential becomes more negative.

Question 10

ion channel

Answer 10

Transmembrane protein that opens and close in response to specific signals; allows passage of specific ion types across a cell membrane.

Question 11

ion

Answer 11

Atom that carries a charge; also defined as an atom that has gained or lost an electron.

Question 12

membrane potential

Answer 12

Difference in charge between the inside and outside of the cell.

Question 13

myelin sheath

Answer 13

Specialized insulation surrounding the axon.

Question 14

Na -K ATPase

Answer 14

Moves sodium ions out of the cell and potassium ions in. Both movements are against their concentration gradients.

Question 15

nerve conduction velocity test

Answer 15

Measure of how quickly action potentials move down the neural pathway.

Question 16

neuron

Answer 16

A specialized cell capable of both receiving and sending electrical signals.

Question 17

node of Ranvier

Answer 17

An unmyleinated gap along a neural fiber, usually an axon; area that contains a high density of ion channels and where action potentials are propogated.

Question 18

repolarization

Answer 18

Membrane returns to resting potential.

Question 19

resting potential

Answer 19

Membrane potential when the cell is at rest.

Question 20

saltatory conduction

Answer 20

Jumping movement of the current as it “leaps” from one node of Ranvier to the next along the axon.

Question 21

sodium-potassium pump

Answer 21

Present in animal cells that maintain a low sodium and high potassium ion concentration in the cell; involved in signal transduction in the organism.

Question 22

threshold potential

Answer 22

Point at which depolarization reaches a critical value, triggering an even greater response.

Question 23

voltage-gated

Answer 23

Type of ion channel that responds to changes in membrane potential.

Question 24

autonomic nervous system

Answer 24

The division of the nervous system that controls involuntary actions, such as organ function and physiological homeostasis, via control of smooth and cardiac muscle; distinct from the voluntary motor system that controls skeletal muscle.

Question 25

central nervous system (CNS)

Answer 25

The brain and spinal cord.

Question 26

brain stem

Answer 26

Primitive part of brain, composed of midbrain, medulla oblongata, and pons.

Question 27

cerebral hemisphere

Answer 27

One half of the structure of the mammalian brain encompassing the outermost layers (cerebrum); the most visible structure of folded cortex tissue.

Question 28

cerebrum

Answer 28

Centers of homeostasis, memory, learning, emotions, and other complex functions.

Question 29

forebrain

Answer 29

Portion of the brain consisting of the cerebrum, thalamus, and hypothalamus; regulates the entire nervous system.

Question 30

cerebral cortex

Answer 30

Thin layer of gray matter which covers the cerebral hemispheres and is involved in processing of high-order information.

Question 31

frontal lobe

Answer 31

Contains primary motor cortex and functions in personality as well as planning future events.

Question 32

gray matter

Answer 32

The area of the central nervous system lacking myelin sheaths and containing cell bodies.

Question 33

hypothalamus

Answer 33

Coordinates endocrine and nervous system to maintain body temperature and overall homeostasis.

Question 34

limbic system

Answer 34

Cluster of nerves in the lower forebrain responsible for regulating instincts, long-term memory, and basic physiological drives.

Question 35

occipital lobe

Answer 35

Collects and integrates visual information.

Question 36

parasympathetic nervous system

Answer 36

The subdivision of the autonomic nervous system that causes involuntary relaxation responses.

Question 37

parietal lobe

Answer 37

Contains the primary somatosensory cortex that processes pressure, pain, temperature, and touch information.

Question 38

peripheral nervous system (PNS)

Answer 38

Neurons transmitting information to and from the CNS.

Question 39

somatic nervous system

Answer 39

The division of the nervous system that senses the environmental conditions and controls the muscles of the body.

Question 40

sympathetic nervous system

Answer 40

The subdivision of the autonomic nervous system that causes involuntary fight or flight responses.

Question 41

temporal lobe

Answer 41

Functions in hearing, recognition/identification of familiar objects, and understanding spoken language.

Question 42

thalamus

Answer 42

Gatekeeper of cerebrum; sorts sensory inputs and controls outgoing signals.

Question 43

white matter

Answer 43

Large numbers of axons encased in myelin sheaths that surround the gray matter of the CNS.

Question 44

action potential

Answer 44

Electrically based signal that is passed along the axon.