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24 Cards in this Set
- Front
- Back
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Somatic neurons have how many neurons traveling from the spinal cord? |
one |
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Somatic neurons release which neurotransmitter? |
ACh, which is always excitatory |
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What are the divisions of the autonomic system? |
Sympathetic and parasympathetic |
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How many neurons does the autonomic motor system have? |
two first as cell bodies in the brain or spinal cord and synapses in an autonomic ganglion second has cellbodies in the ganglion and synapses on the effector. |
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What neurotransmitters does autonomic release? |
norepinephrine and epinephrine and may be excitatory or inhibitory |
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Autonomic neuron effectors |
cardiac muscles
smooth muscles of the visceral organs and blood vessels glands part of PNS |
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Preganglioinic |
originate in the midbrain or hindbrain( thoracic, lumbar, or sacral spinal cord) |
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Postganglionic |
located in the head neck, and abdomen and chains along either side of the spinal cord |
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Preganglionic neurons synapse in? |
Sympathetic ganglia that run parallel to the spinal cord |
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Sympathetic neuron pathways |
1. preganglionic axons synapse w/ postganglionic neurons 2. postganglionic axons inntervate target organs |
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Adrenal glands |
adrenal medulla secretes epinephrine and norepinephrine when stimulated by sympathetic nervous system |
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Preganglionic neurons synapse on? They don't travel with? |
preganglionic synapse on ganglia located near or in effector organs = terminal ganglia, supply very sort postganglionic neurons to effectors Preganglionic neurons do not travel with somiatic neurons ( sympathetich postganglionic neurons do) |
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Parasympathetic : Cranial nerves Occulomotor (III) nerve |
Preganglionic fibers exit midbrain and synapse on the ciliary ganglion Postganglionic fibers innervate the ciliary muscle of the eye |
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Vagus (X) nerve |
Preganglionic fibers exit medulla, branch into several plexi and nerves, and travel to ganglia within effector organs |
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Sympathetic functions |
fight or flight response release norepinephrine and epinephrine Prepares body for intense physical activites regulates heart, blood vessels, and other organs |
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Parasympathetic functions |
Rest and digest Antagonistic to sympathetic division Slows heart rate and increases digestive activites |
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ACh is...? |
ACh is neurotransmitter used by all preganglionic neurons ACh is most released fromm parasympathetic postganglionic neurons some sympathetic postganglionic neurons ( those that activate sweat glands) release ACh |
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Neurotransmitter released by sympathetic postganglionic neurons? |
Norepinephrine is the neurotransmitter released the most by sypathetic postganglionic neurons These synapses are called adrenergic |
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Varicosities |
Axons of postganglionic neurons that release nuerotransmitter along the length of the axon Sympathetic and parasympatheic neurons inntervate the same tissues but different neurotransmitters |
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Adrenergic stimulation and inhibition |
Epinephrine and norepinephrine in the blood from symapathetic nerves Stimulate: hearth dilatory muscles of the iris, smooth muscles Inhibiation: bronchioles in the lungs, other blood vessels, inhibits contraction and causes dilation of these structures |
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Alpha adrenergic receptors |
more sensitive to norepineprine |
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Beta adrenergic receptors |
more sensitive to blood epinephrine |
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Organs with Dual innervation |
Most visceral organs are innervated by both sympathetic and parasympathetic neurons Divisions most often oppose each other Complementary effects occur when both divisions produce similar effects on the same target |
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Organs without Dual innervation |
innervated by sympathetic division only adrena medulla sweat glands most blood vessels Regulated by increase and decrease in sympathetic nerve activity Important for body temp regulation through blood vessels and sweat glands |
