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Chapter 10
nervous system
Term | Definition |
---|---|
action potential | nerve impulse |
adrenergic fibers | nerve fibers that secrete norepinephrine |
afferent neuron | sensory nerve that carries impulses toward the central nervous system |
alpha-adrenergic receptors | receptors to norepinephrine that generally produce an excitatory response |
autonomic nervous system | subdivision of the nervous system responsible for regulating activities that maintain homeostasis; called visceral motor system |
axon | fiber extending form a neuron's cell body that conducts impulses |
beta-adrenergic receptors | receptors to norepinephrine that generally produce an inhibitory response |
central nervous system | portion of the nervous system consisting of the brain and spinal cord |
brainstem | stem-like portion of the brain that connects the cerebral hemispheres to the spinal cord; consists of the midbrain, pons, and medulla oblongata |
cerebellum | portion of the brain responsible for coordination of voluntary movement and balance |
cerebral cortex | the surface of the cerebrum consisting of a thin layer of gray matter |
cerebrospinal fluid | clear, colorless fluid that fills the brain's ventricles and central canal and also bathes the outside of the brain and spinal cord |
cerebrum | largest portion of the brain |
cholinergic fibers | nerve fibers that secrete acetylcholine |
cranial nerves | nerves of the peripheral nervous system that arise directly from the brain instead of from the spinal cord |
dermatome | a specific area of the skin innervated by a spinal nerve |
efferent neuron | motor nerve that carries impulses away from the central nervous system |
epidural space | small space between the outer covering of the spinal cord and the vertebrae |
frontal lobe | portion of the cerebrum responsible for decision making, reasoning, memory, and voluntary movements |
gray matter | nervous tissue containing mostly cell bodies of motor neurons and interneurons |
hypothalamus | the bottom half of the diencephalon of the brain, which is responsible for many vital body functions |
limbic system | complex set of structures in the brain responsible for emotion and leaning |
medulla oblongata | attaches to spinal cord; contains centers that govern heart rate, blood pressure, and breathing |
meninges | layer of fibrous connective tissue covering the brain and spinal cord |
mixed nerve | nerve that contains both sensory and motor fibers |
myelin | fatty sheath encasing the axons of many neurons; formed by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system |
nerve | a bundle of neurons that transmits impulses between the brain and spinal cord and the rest of the body |
neuroglia | cells in the nervous system that support neurons but do not conduct impulses |
neurons | nervous system cells that conduct impulses |
occipital lobe | portion of the cerebrum responsible for analyzing and interpreting visual information |
parasympathetic division | division of the autonomic nervous system that primarily has a calming effect; "rest and digest" |
parietal lobe | portion of the cerebrum concerned with bodily sensations and proprioception |
peripheral nervous system | portion of the nervous system consisting of the network of nerves throughout the body |
plexus | a network of nerves |
polarization | the electrical state of a cell membrane that has an excess of positive ions on one side of the membrane and an excess of negative ions on the other sides |
reflex arc | a neural circuit that bypasses regions of the brain where conscious decisions are made |
somatic reflex | reflex involving contraction of a skeletal muscle after being stimulated by a somatic motor neuron |
sympathetic division | division of the autonomic nervous system responsible for "fight or flight" response |