Term
| Major subdivisions of ANS |
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Definition
1. parasympathetic (CNS and PNS)
2. sympathetic (CNS and PNS)
3. enteric (confined to walls of digestive tract) |
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Term
| Types of Visceral Sensory Receptors |
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Definition
1. nociceptors
2. physiologic receptors |
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Term
| Characteristics of nociceptors |
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Definition
1. respond to stimuli in damaged tissue or potential to be damaged
2. visceral pain--dull and difficult to localize
3. may include referred pain--crossing of ANS and somatic sensory nerves
4. carried by afferent nerve fibers of sympathetic ANS |
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Term
| Characteristics of Physiologic Receptors |
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Definition
1. respond to innocuous stimuli
2. monitor visceral functions and elicit visceral reflexes for homeostasis
3. carried by afferent nerve fibers of parasympathetic portion of ANS |
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Term
| Examples of physiologic receptors |
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Definition
1. chemoreceptors (carotid and aortic bodies)
2. mechanoreceptors (stretch, tension--Lower esophageal sphincter)
3. baroreceptors (arterial blood pressure) |
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Term
| Target cells of efferent nerve fibers of ANS |
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Definition
1. vascular smooth muscle
2. non-vascular smooth muscle
3. cardiac muscle cells
4. secretory epithelial cels (mucous cells)
5. gastrointestinal endocrine cells (cholecystokinin-secreting cells) |
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Term
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Definition
1. walls of gut from esophagus to anal canal
2. myenteric (Auerbach) and submucosal (Meissner's) plexus (all kinds of neurons and glia)
3. also to gallbladder, cystic duct, bile duct, pancreas
4. 100 million neurons
5. control over digestion
6. extensive communication with CNS--parasympathetic and sympathetic portions of ANS provide link |
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Term
| Parasympathetic and Sympathetic ANS |
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Definition
1. wide distribution, interacts wit major viscera
2. parasympathetic--anabolic processes, restoration, and conservation of energy
3. sympathetic--deal with stressful situations
4. basal rates contribute to "tones" |
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Term
| Dual Innervation of organ |
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Definition
1. most organs innervated by both parasymp and symp.
2. normal activity reflects parasymp and symp tones until it needs t be changed |
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Term
| Single Innervation of Organ |
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Definition
1. only one nervous system regulates activity
2. blood vasculature (arterioles) to skin and skeletal muscles |
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Term
| Selective Activation of Target Organs |
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Definition
| 1. activation of 1 organ is done independently of other organs innervated by the same system |
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Term
| Somatic Distribution of Para and Sympath NS |
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Definition
1. body wall and extremities--> skeletal muscle, bone, and skin
2. sympathetic to smooth muscle of vasculature, secretory glands, arrector pili
3. NO parasympathetic distribution |
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Term
| Visceral Distribution of Para and Sympa |
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Definition
| 1. viscera of thoracic, abdominal cavities, perineum, and pelvic cavity receive both symp and para |
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Term
| Head Innervation by Para and Sympa |
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Definition
1. eyes and salivary glands receive both
2. vasculature, sweat glands, and arrector pili receive sympathetic like other somatic structures |
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Term
| Sensory neurons of Para and Sympa |
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Definition
1. pseudounipolar with cell bodies in ganglia outside CNS
2. sensory of sympathetic: cell bodies in dorsal root ganglia in some spinal nerves (no cranial nerves have sympa)
3. sensory of para: cell bodies are in ganglia of spinal nerves and ganglia of cranial nerves
4. In PNS, follow same course as visceral efferent nerve fibers |
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Term
| Motor Neurons of Para and Sympa |
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Definition
1. 2 neuron chain--preganglionic neuron with cell body in CNS (myelinated), postganglionic neuron with cell body in PNS ganglion (unmyelinated)
2. amplification of efferent single (1:2 to 1:20 preganglionic: postganglionic)
3. postganglionic of para=acetylcholine and vasoactive intestinal peptide
4. postganglionic of sympa=norepinephrine and neuroteptide Y |
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Term
| Location of Preganglionic Nerve Cell Bodies in Parasympathetic System |
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Definition
1. craniosacral portion of ANS
2. brainstem nuclei of CN 3, 7, 9, 10
3. S2-S4 of spinal cord
4. most preganglionic derived from vagus nerve |
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Term
| Location of Postganglionic Nerve Cell Bodies in Parasympathetic System |
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Definition
1. small and located within or adjacent to walls of organ being innervated
2. some functionally integrated into enteric NS
3. preganglionic are long in comparison to postganglionic |
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Term
| Location of Sympathetic Preganglionic Nerve Cell Bodies |
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Definition
1. thoracolumbar portion
2. T1-L3 spinal cord DRG |
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Term
| Location of Sympathetic Postganglionic Nerve Cell Bodies |
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Definition
1. preganglionic are short compared to postganglionic
2. sympathetic trunks (paravertebral): parallel to vertebral column from neck to sacrum (-25 pearls on a string)
3. prevertebral: limited to abdominal cavity, anterior to vertebral column, and adjacent to major branches of abdominal aorta (i.e. celiac ganglion) |
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Term
| Sympathetic Innervation of somatic structures: postganglionic (except head) |
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Definition
1. preganglionic leave as anterior roots of T1-L3 spinal nerves
2 enter sympathetic trunks (white rami communicates)
3. postganlionic acons send axons back to T1-L3 spinal nerves and distribute to body (gray rami communicantes) |
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Term
| Somatic innervation of head |
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Definition
1. preganglionic axons from head enter synapse on most superior part of sympathetic trunk (superior cervical ganglia)
2. postganglionic axons jump onto carotid arteries and distribute via periarterial nerve plexus |
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Term
| Sympathetic innervation of head |
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Definition
| same as somatic innervation to head |
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Term
| sympathetic innervation of thoracic viscera |
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Definition
1. preganglionic axons from T1-T5 spinal cord
2. postganglionic axons exit cervical and upper thoracic ganglia of symp. trunks
3. project to cardiac and pulmonary nerve plexuses
4. Join with preganglionic axons of vagus nerve and follow periarterial nerve plexus to heart and lungs |
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Term
| Sympathetic innervation of abdominal and pelvic viscera |
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Definition
1. preganglionic axons from T5-L3 enter sympathetic trunks but do not synapse
2. These splanchnic nerves course to prevertebral ganglia
3. postganglionic course to target organs via periarterial nerve plexus |
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Term
| Influences of ANS from Higher Brain Centers |
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Definition
1. Input from reticular formation, hypothalamus, thalamus, limbic lobe, prefrontal cortex
2. accounts for effects of exterior sensory cues, emotional status, and cerebral function on ANS activity |
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Term
| Influences of ANS from Higher Brain Centers |
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Definition
1. Input from reticular formation, hypothalamus, thalamus, limbic lobe, prefrontal cortex
2. accounts for effects of exterior sensory cues, emotional status, and cerebral function on ANS activity |
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