Parasympathetic NS (craniosacral)

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• Parasympathetic NS (craniosacral)
• Preganglionic neurons.
• Cranial outflow.
• - occulomotor (III)
• - facial (VII)
• - glossopharyngeal (IX)
• - vagus (X)
• Sacral outflow..2nd, 3rd and 4th sacral segments
• Post ganglionic neurons . terminal ganglia

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• The parasympathetic division often produces
  antagonistic effects to sympathetic division
  through the release of acetylcholine from its
  post ganglionic fibers

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Functions of Parasympathetic Nervous System

• 1- Head Neck
• Occulomotor Nerve (3rd cranial nerve) ?
  Pupil constriction (miosis) ? increase
  power of lens necessary for
• near vision
• Facial nerve (7th cranial nerve) A-
  Secretomotor vasodilator to the submandibular
  sublingual salivary glands B- secretion of
  lacrimal nasal glands.
• Glossopharynqeal nerve (9th cranial nerve)
  Secretomotor vasodilator to parotid
  
• gland.

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Functions of Parasympathetic Nervous System

• Thorax Abdomen are supplied by Vagus nerve
  (10th cranial nerve )
• 2- Thorax
• Heart ? Inhibition of all atrial properties
• (NO vagal supply to
  ventricles) ? Decrease coronary flow
  02
• consumption
• Lungs ? Bronchial constriction
  ? Dilatation of pulmonary blood vessels
  ? Increase bronchial secretion.

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Functions of Parasympathetic Nervous System

• (3) Abdomen
• GIT ? Motor to esophagus, stomach, small
• intestine, proximal part of large
  intestine
• ? Inhibitory to sphincters ?
  Secretory to glands of stomach, small
• intestine, liver, pancreas
• Gall bladder ? Motor to wall
• ? Inhibitory to
  sphincters
• i.e. Evacuation of gall
  bladder.

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Functions of Parasympathetic Nervous System

• (4) Pelvis sacral outflow
• a) Defecation
• b) Micturition
• c) MaIe genitalia
• ? Erection
• ? Secretory to seminal vesicle
  
• prostate

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Organ Parasympathetic Response"Rest and Digest" Sympathetic Response"Fight or Flight"
Heart Decreased heart rateCardiac output decreases Increased rate and strength of contraction Cardiac output increases
Lung Bronchioles Constriction Dilation
Liver Glycogen No effect Glycogen breakdownBlood glucose increases
Fat Tissue No effect Breakdown of fatBlood fatty acids increase
Basal Metabolism No effect Increases 2X
Stomach Increased secretion of HCl digestive enzymesIncreased motility Decreased secretionDecreased motility
Intestine Increased secretion of HCl digestive enzymesIncreased motility Decreased secretionDecreased motility
Urinary bladder Relaxes sphincterDetrusor muscle contractsUrination promoted Constricts sphincterRelaxes detrusorUrination inhibited
Rectum Relaxes sphincterContracts wall musclesDefecation promoted Constricts sphincterRelaxes wall musclesDefecation inhibited
 Eye Pupils constrictAdjusts for near vision Pupils dilateAdjusts for far vision
Male Sex Organs Promotes erection Promotes ejaculation
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Chemical transmitters in autonomic nervous system

• Acetylcholine
• Noradrenaline (Norepinephrine)

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• Acetylcholine
• Sites of release of acetylcholine
• All preganglionic autonomic fibers (sympathetic
  para sympathetic )
• preganglionic sympathetic fibers to suprarenal
  medulla
• All postganglionic para sympathetic fibers
• postganglionic sympathetic fibers to sweet glands
  and blood vessels of skeletal muscle ( VD)
• Removal of acetylcholine
• It is split into acetate choline by
  acetylcholine esterase
• True acetylcholine esterase ? cholinergic
  nerve endings
• Pseudo acetylcholine esterase ? in plasma

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Cholinergic receptors

• Nicotinic receptors
• -autonomic ganglia
• -skeletal muscles ( motor end plate)
• -suprarenal medulla
• Muscarinic receptors
• -viscera supplied by postganglionic para
  sympathetic fibers
• -sweet glands and blood vessels of skeletal
  muscle ( sympathetic cholinergic
  fibers)

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• Nor adrenaline (Norepinephrine)
• Sites of release of Noradrenaline
• All postganglionic sympathetic fibers except
  fibers to sweet glands and blood vessels of
  skeletal muscle
• Fate of Noradrenaline
• Re-uptake into the adrenergic nerve endings
• Diffusion away into the body fluids plasma
• Destruction by
• MAO ( monoamin oxidase)
• COMT ( catechol-O methyl transferase)

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• Adrenergic receptors
• Alpha receptors
• Alpha 1 and alpha 2
• Alpha 1 ?Excitatory ( intracellular Ca )
• Vasoconstriction
• Contraction of sphincter of GIT, dilator pupillea
  , spleniccapsule, seminal vesicles and vas
  deferens
• Alpha 2 ? inhibitory to intestinal wall (
  c-AMP)
• Beta receptors
• Beta 1 ? excitatory, heart metabolic action
• Bate 2 ? inhibitory,smooth muscles of
  bronchi, urinary bladder, intestine, VD of
  skeletal muscle ( c-AMP)