Term
| 2 subdivisions of the peripheral nervous system |
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Definition
1. somatic motor neurons (control skeletal muscles)
2. autonomic motor neurons (control smooth muscle, cardiac muscle, many glands, & some adipose tissue) |
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Term
| 2 subdivisions of the autonomic division |
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Definition
1. sympathetic branch
2. parasympathetic branch |
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Term
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Definition
| one of the most dramatic examples of sympathetic action; the brain triggers massive simultaneous sympathetic discharge throughout the body |
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Term
| 4 Walter Cannon's properties of homeostasis displayed by the sympathetic & parasympathetic branches of the autonomic nervous system |
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Definition
1. preservation of the fitness of the internal environment
2. up-down regulation by tonic control
3. antagonistic control
4. chemical signals with different effects in many tissues |
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Term
| The first neuron in an autonomic pathway, the _____, originates in the CNS & projects to an _____ outside the CNS |
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Definition
| preganglionic neuron; autonomic ganglion |
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Term
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Definition
| the second neuron in the autonomic pathway onto which the preganglionic neuron synapses in the autonomic ganglion |
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Term
| 2 main anatomical differences between the two autonomic branches |
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Definition
1. the pathways' point of origin in the CNS
2. the location of the autonomic ganglia |
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Term
| The major parasympathetic tract is the _____, which contains about 75% of all parasympathetic fibers |
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Definition
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Term
| 3 rules to distinguish sympathetic & parasympathetic branches chemically (using their neurotransmitters & receptors) |
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Definition
1. both sympathetic & parasympathetic preganglionic neurons release acetylcholine onto nicotinic cholinergic receptors on the postganglionic cell
2. most postganglionic sympathetic neurons secrete norepinephrine onto adrenergic receptors on the target cell
3. most postganglionic parasympathetic neurons secrete acetylcholine onto muscarine cholinergic receptors on the target cell |
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Term
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Definition
| the synapse between a postganglionic neuron & its target cell |
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Term
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Definition
| a swelling on the autonomic postganglionic axon that contains vesicles filled with neurotransmitter |
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Term
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Definition
| the main enzyme responsible for degradation of catecholamines that breaks down recycled norepinephrine that isn't repackaged |
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Term
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Definition
| the most common sympathetic receptor; respond strongly to norepinephrine & only weakly to epinephrine |
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Term
| 3 main subtypes of beta receptors that differ in their affinity for catecholamines |
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Definition
1. beta1-receptors (respond equally strongly to norepinephrine & epinephrine)
2. beta2-receptors (more sensitive to epinephrine than to norepinephrine)
3. beta3-receptors (found primarily in adipose tissue; more sensitive to norepinephrine than to epinephrine) |
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Term
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Definition
| activate phospholipase C, creating triphosphate & diacylglycerol |
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Term
| The _____ is a specialized neuroendocrine tissue associated with the sympathetic nervous system |
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Definition
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Term
| Both sympathetic & parasympathetic pathways consist of how many neurons in series? |
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Definition
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Term
| Do all preganglionic autonomic neurons secrete acetylcholine onto nicotinic receptors? |
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Definition
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Term
| Where do sympathetic pathways originate? |
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Definition
| in the thoracic & lumbar regions of the spinal cord |
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Term
| Where are most sympathetic ganglia located? |
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Definition
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Term
| Which branch of the autonomic motor system controls functions that are useful in stress or emergencies? |
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Definition
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Term
| neuromuscular junction (NMJ) |
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Definition
| the synapse of a somatic motor neuron on a muscle fiber |
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Term
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Definition
1. the motor neuron's presynaptic axon terminal filled with synaptic vesicles & mitochondria
2. the synaptic cleft
3. the postsynaptic membrane of the skeletal muscle fiber |
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Term
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Definition
| a series of folds that look like shallow gutters; what the muscle cell membrane that lies opposite the axon terminal on the postsynaptic side of the NMJ is modified into |
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Term
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Definition
| the enzyme that rapidly deactivates ACh by degrading it into acetyl & choline |
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