Fichas
Autonomic Nervous System
Fichas del conjunto (25)
- 1Spinal ChordSensory and motor neurones enter and exit via spinal nerve between vertebrate and 12 cranial nerves from brain
Sensory = dorsal, motor = ventral - 2Sensory neuronesBodies in dorsal route ganglion
Synapse with grey matter - 3Alpha motor neuronesBodies in ventral horn of grey matter
White matter = myelination
Direct to skeletal muscle without synapseing - 4Skeletal muscleRespond to external and internal e.g. ventilation/ shivering - homeostatic
- 5HomeostasisSmooth muscle, cardiac muscle, secretory glands
- 6The ANSSympathetic
Parasympathetic
Enteric - 7SympatheticShort pregangionic neurone (ACh or adrenal
Long postganglionic neurone - 8ParasympatheticLong preganglionic,
ACh to short post ganglionic
Vagus nerve carries parasympathetic signals to most of body - mixes neurones - 9Sympathic Nervous SystemCell bodies in intermediolateral column of grey matter
parallel chain
ACh transmitters
Longer post ganglionic noradrenaline to organ (some unusual ACH e.g. sweat)
Someone adrenal gland to release adrenalin - 10Adrenergic ReceptorsAdrenaline and noradrenaline on F-protein adrenoreceptors. Both alpha and beta catecholamines activate all subtypes, but noradrenaline better at 1 and adrenaline 2
B couple to G proteins - increase cAMP, Alpha 2 couple to inhibitory G protein. Alpha 1 via GQ to inositol phospholipid pathway
Effects depend on how many receptors expressed and what kind - 11Parasympathetic Nervous SystemMyelinated preganglionic
From brain in cranial nerves to target organs. Thoracic and abdominal form vagus nerve
Preganglionic synapse close with target or wall itself. ACh transmitter.
Short, unmyelinated post ganglionic release ACh on muscarinic receptors
Some release VIP or NO - 12AtropineBlocks muscarinic receptors
- 13Control of heartIncreased by sympathetic adrenaline and noradrenaline, Decreased by parasympathetic ACh
Tonic parasympathetic stimulation from vagus nerve at rest - 14Process for increasing HRB! adrenoreceptor on SAN respond to catecholamine by activating G protein, increasing cAMP. Na+ and Ca2+ channels open for depolarisation- more rapid
- 15CaffeinePhosphodiesterase inhibitor - prolonges cAMP effects
- 16Decreasing HRVagal ACH on muscarinic receptors activates different G protein in SAN
Dissociated alpha subunit inhibits adenylate cyclase, reduiing cAMP levels.
Betagamma subunit directly opens K+ channels to hyper polarise - 17Otto Leowi 1921Removed heart with vagus attached and one without
put in ringer
Electrically stimulated vagus nerve, making heart beat slower
Took some ringer and put with other heart, caused to beat slower
Proves chemical released by vagus controls heart rate - 18ForceParasympathetic has little impact on force
- 19Autonomic control of blood vesselsSympathetic tone maintained by noradrenergic fibres (basal constriction). changing tone changes constriction
Adrenalin causes vasodilation of skeletal at normal levels
Can be widespread or more targeted - 20ParasympatheticCertain restricted areas e.g. salivary glands. little influence
- 21PenisRelease NO and VIP onto smooth muscle. NO diffuse into cells and activates granulate cyclase, increasing cGMP adn causing relaxation
cGMP broken down by phosphodiesterase type 5 enzyme
Viagra inhibits enzyme to remain relaxation (erection) longer - 22Sympathetic "fight or flight"increase HR
exercising muscle dilatation
glucose mobilised
gastrointestinal activity halted
pupils dilate
hair on end
Deals with acute stress - animal can survive as long as no homeostasis threatening situation - 23Parasympathetic "rest and digest"motility and section by digestive system
Slow conducting postganglionic shorter than sympathetic hence quicker response and more precise - 24Ending autonomic effectsMost noradrenaline by uptake 1 mechanism and recycled
Adrenaline into wide range of tissues by uptake 2 and degrade in cells. end products secreted in urine
ACH by acetylcholinesterase. choline recycled - 25CocaineBlock uptake of noradrenaline, maintaining sympathetic effects
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- (Communication Between Cells) Physiology of Organisms Fichas sobre Autonomic Nervous System, creado por Alice Hathaway el 07/01/2019.
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- Alice Hathaway
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