Term
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Definition
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Definition
| conduct information toward the cell body |
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Definition
| carries impulses away from cell body |
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Definition
PNS - Schwann cells
CNS - oligodendrocytes, astrocytes (astroglia), microglia, ependymal |
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Definition
| produce the myelin sheath = rapid conduction of nerve impulses |
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Definition
| form the myelin (multilayered around several axon = increase velocity of nerve conduction |
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Term
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Definition
| largest and most numerous - form network, facilitate communication, involved with scar tissue in the brain (gliosis) |
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Definition
| small, phagocytic - clean up debris |
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Definition
| lining of neural tube cavity, ventricular system (choroid plexus - production of CSF) |
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Term
| nervous tissue metabolic requirement |
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Definition
15% of resting cardiac output
20% of it's oxygen |
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Term
| functional importance of ion channels |
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Definition
| they change the polarity of the cell - stimulating the action potentials (communication between neurons) |
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Term
| phases of action potential |
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Definition
resting membrane potential (-90mV)
depolarization (+30 to +45mV)
repolarization |
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Term
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Definition
| -60mV; when reached opens ion channels (all or nothing, fully open or fully closed) |
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Term
| resting membrane potential |
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Definition
| -90mV; polarized (pos in/ neg out of cell) but no electrical activity - not transmitting impulses |
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Term
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Definition
| +30 to +45mV; sodium channels open = rapid inflow of sodium ions that generate the electrical impulse |
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Term
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Definition
| close sodium channels, open potassium channels = efflux of potassium and return of resting membrane potential |
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Term
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Definition
| structures that permit communication between neurons |
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Term
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Definition
| consist of gap junctions between adjacent cells that allow action potentials to move rapidly from one cell to another |
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Term
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Definition
| involve special presynaptic and postsynaptic structures, separated by a synaptic cleft. They rely on chemical messengers - released from presynaptic neuron - cross synaptic cleft - interact with receptors of postsynaptic neuron |
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Term
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Definition
| chemical messengers that control neural function; they interact with cell membrane receptors to selectively cause excitation or inhibition of action potentials |
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Term
| 3 major types of neurotransmitters |
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Definition
amino acids (glutamic acid and GABA)
peptides (endorphins and enkephalins)
monoamines (epinephrine and norepinephrine) |
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Term
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Definition
| chemical messengers that react with membrane receptors to produce slower and longer-acting changes in membrane permeability |
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Term
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Definition
| growth factors - released from presynaptic terminals - required to maintain the long-term survival of postsynaptic neurons |
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Term
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Definition
| forebrain controls the brain stem, the brain stem controls the spinal cord |
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Term
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Definition
connects neighboring segments
contains neurons - reticular activating system
reticular formation |
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Term
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Definition
reticular activating system
responsible for regulating arousal and sleep wake transitions |
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Term
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Definition
| site of many important spinal cord and brain stem reflex circuits |
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Term
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Definition
fibers reach to the brain stem
longitudinal communication between more distant segments of nervous system; track systems for sensation and movement |
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Term
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Definition
pathways for bladder control and fine motor skills
develop by fifth year of life
become functional in infancy and childhood, very delicate and discriminate function |
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Term
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Definition
medulla oblongata, cerebellum, and pons
gives rise to cranial nerves V-XII controlling viscera, hearing, facial, and mouth/throat functions
aka brain stem |
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Term
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Definition
cerebral peduncles, cerebral aquaduct, superior colliculi, inferior colliculi
gives rise to cranial nerves III and IV controlling eye movement |
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Term
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Definition
thalamus, hypothalamus, cerebrum
gives rise to cranial nerves I and II for smell and sight |
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Term
| functions of the hindbrain |
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Definition
reflex centers for heart and respiration rates, coughing swallowing, vomiting, etc.
cerebellum allows fine motor coordination |
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Term
| functions of the midbrain |
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Definition
cerebral peduncles carry nerve fibers from the cerebrum to the hindbrain
cerebral aqueduct lets CSF drain from the 4th ventricle inside the cerebrum
superior colliculi control reflex eye movements
inferior colliculi control reflex reactions to sound |
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Term
| functions of the forebrain |
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Definition
thalamus "switchboard" or relay station for impulses going to and coming from the cerebrum
hypothalamus homeostatic control |
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Term
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Definition
frontal lobe: motor, anticipation
parietal lobe: somatosensory
temporal lobe: hearing, memory
occipital lobe: vision
limbic system: emotional |
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Term
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Definition
2 layers
inner layer separates the cerebral hemispheres
venous blood drains out of the brain in a sinus
bridging veins carry blood from the brain across the inner layer of the dura mater to the sinus
sinus also collects CSF |
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Term
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Definition
lies just beneath dura mater
waterproof
CSF lies under arachnoid to cushion the brain
villi (extensions of arachnoid) poke through the inner layer of the dura mater into the sinuses to let CSF drain into the sinuses |
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Term
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Definition
lies right on the surface of the brain
holds the cerebral arteries in place |
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Term
| meninges (system of membranes the envelope the CNS) and meningeal spaces |
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Definition
epidural space: meningeal arteries
dura mater: subdural space: bridging veins
arachnoid: subarachnoid space: cerebral arteries, CSF
pia mater |
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Term
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Definition
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Term
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Definition
| leaks out of capillaries inside the brain's hollow ventricles (composition controlled by the blood-brain barrier) - passes out an opening below the cerebellum - circulates around the brain and spinal cord in the subarachnoid space - passes through arachnoid villi into blood in the dural sinuses and is returned to the heart |
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Term
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Definition
catecholamines
epinephrine, norepinephrine, dopamine
attach to adrenergic receptors |
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Term
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Definition
sympathetic
parasympathetic |
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Term
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Definition
acetylcholine
attaches to cholinergic receptors |
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Term
| neurotransmitters for sympathetic postganglionic neurons |
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Definition
| norepinephrine and epinephrine |
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Term
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Definition
neurotransmitter for
sympathetic: preganglionic
parasympathetic: preganglionic and postganglionic |
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Term
| adrenergic neurotransmitters |
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Definition
synthesized in the sympathetic system
attach to adrenergic receptors
neurotransmitter is removed from synapse by reuptake or degraded by enzymes |
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Term
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Definition
alpha 1: constrict blood vessels
alpha 2: negative feedback to stop neurotransmitter release
beta 1: speed and strengthen heart
beta 2: bronchodilation |
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Term
| cholinergic neurotransmitter - acetylcholine |
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Definition
released from parasympathetic system from motor neurons
attaches to cholinergic receptors
neurotransmitter is removed from the synapse by acetylcholinesterase |
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Term
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Definition
nicotinic: excite skeletal muscle cells
muscarinic: slow heart, stimulate GI tract, vasodilate |
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Definition
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Definition
efferent (away from CNS)
motor |
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