NEURO 375 AUTONOMIC NERVOUS SYSTEM |31 QUESTIONS WITH 100% CORRECT ANSWERS

how is the autonomic PNS different from the somatic PNS? - autonomic PNS is a two neuron pathway from spinal cord to effector whereas the somatic PNS is a one neuron path - motor axons of the autonomic PNS have cell bodies outside of the CNS whereas somatic LMN have cell bodies within the CNS - autonomic PNS is responsible for innervating visceral tissues whereas somatic PNS is responsible for innervating body wall tissue (motor division) - somatic sensation = of body wall and is well localized for tough, proprioc. pain... where autonomic sensory division innervates visceral tissue for pain and stretch - autonomic NS has sympathetic and parasympathetic efferents where the somatic does not How is the DRG different from the autonomic ganglia ? describe the autonomic motor system ? - preganglionic cell bodies within spinal cord (lateral horn) - post-ganglionic cell bodies lie in periphery (sympathetic chain, near tissue...) - takes TWO neurons to get from CNS to effector - effectors are visceral targets (glands, cardiac tissue, smooth muscles..) how do cranial meninges differ from spinal meninges dura mater : - cranial = double layered and attached to calvarial surface - spinal = single layered and suspended in vertebral canal arachnoid villi : - cranial = attached to dura matter - sacral - attached to dura matter epidural space : - cranial: potential space between periosteum and calverna - spinal : real space between dura and vertebral periosteum pia mater: - cranial :attached to brain surface - spinal attached to spinal cord and dura/arachnois (denticuate legements) Filum terminale pia matter that attaches to the coxxygeal bone conus medullaris sacral part of spinal cord (ends at L1/L2) what spinal segments does the sympathetic ns origonate from thoracolumbar (t2-t12 and l1-l4) from laminae v11 od spinal cord what spinal segments does the parasympathetic ns origonate from craniosacral outflow (c1-c4, l5-s2) - preganglionic cell bodies in laminae VII of spinal cord differentiate the structure of the somatic vs autonomic PNS somatic : - from somatic mesoderm - parietal membranes - skin bones and muscles of body wall Autonomic : - from splanchnic mesoderm - innervates viscera (liver, glands, heart, lungs, blood vessels..) - visceral membranes (ppp) differentiate the motor nerve supply of the somatic vs autonomic PNS somatic skeletal mucles innervation autonomic - sympathetic (T1-L2) - parasympathetic (CN's III, VII, IX, X and S2,3,4) differentiate the sensory nerve supply of the somatic vs autonomic PNS somatic - responds to ALL modulities (pain, tough, temp, chemo..) - pain is SHARP and well localized autonomic - visceral afferents travel with sympathetic and parasympathetic nerves - respond to stretch and ischemia - pain is DULL and not well localized parasympathetic cell bodies - preganglionic = brainstem nuclei of CN II, VII, IX and X and in the sacral spinal cord at levels S2,3,4 - postganglionic = found in autonomic ganglia close to target sympathetic cell bodies - preganglionic = found in spinal cord laminae VII in segments T1-L1/2 - postganglionics = found in paravertebral or prevertebral (in gut) ganglia Eg of parasympathetic motor and sensory signalling ; Vagus innervation of the stomach the vagus nerve innervates both the affernt sensations and the efferent motor division of the stomach - sensation of distention of stomach is carried to the NTS by the vagus nerve - NTS send info to hypothalamus - hypothalamus causes DMNV activation for the vagus nerve to promote digestion (parastalsis) parasympathetic response - dilates blood vessels that lead to the GI tract (promote digestion) - dedicated cardiac branched of the vagus nerve = control over heart - accomidates lense (EW nucleus to ciliary ganglion) - constricts pupils - innervates ALL internal organs but NONE in body wall ( does NOT innervate skin) - salivary glands sympathetic response - pre-ganglionics in the lateral horn of laminae VII from T1-L2 - post-ganglionics project to entire body (UNLIKE parasympathetic motor division) - dilates bronchioles - dilates vessels for muscles - far vision (relax ciliary muscle) and pupil dilation - sweat (Ach) - inhibits digestion A) How does the sympathetic division innervate the skin of the dermatome of its own spinal segment 1. pre-ganglionic efferent from lateral horn to join with somatic efferents in the ventral root 2. pre-ganglionic efferent enters that segments spinal nerve (with somatic efferents and sensory afferents) 3. pre-ganglionic efferent enters white ramus comminicans to get to sympathetic chain where their ganglia is 4. synapse. prost-ganglionic efferent leaves sympathetic chain via grey ramus communicans to REJOIN with spinal nerve of that segment 5. prost-ganglionic innervates skin of that dermatome (ventral and dorsal rami) B) How does the sympathetic division innervate the skin of dermatome above T1 1. pre-ganglionic efferent from lateral horn to join with somatic efferents in the ventral root 2. pre-ganglionic efferent join with spinal nerve of THAT segment 3. pre-ganglionic efferent eneter white ramus comminicans to enter sympathetic chain where their ganglia is 4. synapse POST-ganglionic efferent travels UP the sympathestic chain 5. post-ganglionic efferent exits through grey ramus communicans to join with spinal nerve above T1 to inervate its dermatome C) How does the sympathetic division innervate its visceral effectors (not GUT) from t1-l2? 1. pre-galnglionic travels from lateral horn to ventral root 2. Pre-ganglionic joins with the spinal nerve of that segment 3. pre-ganglionic enters sympathetic chain via white ramus communicants 4. synapse. postganglionic takes a direct route to its effectors via a sympathetic nerve (eg to the heart) D) How does the sympathestic division innervate visceral efferents above or bellow t1-L2 1. preganglionic travels from lateral horn to the ventral root 2. preganglionic joins with sympathetic nerve 3. preganglionic enters sypathetic chain vis white ramus communicans 4. the PRE-ganglionic fiber travels up the sympathetic chain (unlike in the innervation of skin where the post ganglionic nuron traveled uo the chain) 5. the PRE-ganglionic synapses with its post-ganglionoc fibre at an alternative segmental level of the sympathetic chain 6. the postganglionic nerve then exits vis a sympathetic nerve to its effector (because effector is not skin, does NOT rejoin with spinal nerve)