2.2.1 Key Terms

Question 1

Axon

Answer 1

Long nerve cell process that usually conducts impulses away from the cell body

Question 2

Dendrite

Answer 2

Any of the usually conducts impulses toward the body of a neuron

Question 3

Ion

Answer 3

Atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one of more electrons

Question 4

Myelin sheath

Answer 4

In a neuron, an insulating coat of cell membrane from Schwann cells that is interrupted by nodes of Ranvier

Question 5

Neurologist

Answer 5

Physician skilled in the diagnosis and treatment of disease of the nervous system

Question 6

Neuron

Answer 6

Nerve cell; the fundamental unit of the nervous system, having structure and properties that allow it to conduct signals by taking advantage of the electrical charge across its cell membrane

Question 7

Neurotransmitter

Answer 7

Substance (as norepinephrine or acetylcholine) that transmits nerve impulses across a synapse

Question 8

Reaction time

Answer 8

Time elapsing between the beginning of the application of a stimulus and the beginning of an organisms reaction to it

Question 9

Reflex

Answer 9

Automatic and often inborn response to a stimulus that involves a nerve impulse passing inward from a receptor to the spinal cord and thence outward to an effector (as a muscle or gland) without reaching the level of consciousness and often without passing to the brain

Question 10

Synapse

Answer 10

Place at which a nervous impulse passes from one neuron to another

Question 11

Action potential

Answer 11

Momentary reversal in electrical potential across a plasma membrane (as of a nerve cell or muscle fiber) that ovcurs when a cell has been activated by a stimulus