| A | B |
|---|
| action potential | sequence of charges in the membrane potential that occurs when a cell is stimulated to threshold. It includes depolarization and repolarization; also called the nere impulse and the cardiac impulse |
| afferent neuron | carrying toward a center, such as afferent nerves carrying information toward the central nervous system |
| adrenergic fiber | a neurone that secretes norepinephrine as its neurotransmitter |
| autonomic nervous system | involuntary or automatic nervous system that controls the organs, glands, cardiac muscle, and smooth muscle; two divisions are the sympathetic and parasympathetic nervous systems |
| brain stem | lower part of the brain that connects the brain with the spinal cord; consists of the midbrain, pons, and medulla oblongata |
| beta-adrenergic receptors | a type of receptor that is activated by norepinephrine |
| cerebellum | part of the brain located under the cerebrum; it coordinates skeletal muscle activity |
| cerebrum | largest and uppermost part of the brain, divided into two cerebral hemispheres; there are four lobes - frontal, parietal, temporal, and occipital |
| cerebrospinal fluid | cushioning fluid that circulates within the subarachnoid space around the brain and spinal cord |
| cranial nerves | the 12 pairs of nerves that emerge from the brain |
| cholinergic fiber | a neuron that secretes acetylcholine as its neurotransmitter |
| craniosacral outflow | parasympathetic activity |
| depolarize | change in the membrane potential across the cell membrane, with the inside of the cell becoming less negative or less polarized |
| dermatome | area of the body supplied by a spinal nerve |
| efferent neuron | a motor neuron; brings information from the CNS to the periphery |
| frontal lobe | anterior portion of the cerebrum that controls voluntary skeletal activity and plays an important role in emotions, critical thinking, and ethical decision making |
