Autonomic Nervous Autonomic Nervous SystemSystem

Professor of PhysiologyProfessor of Physiology

Division of the A.N.SDivision of the A.N.S

1)sympathetic1)sympathetic Origin :thoracolumbarOrigin :thoracolumbar Short preganglionicShort preganglionic Long postganglionicLong postganglionic The ganglia The ganglia

paravertebral paravertebral &colateral&colateral

The effect generalizedThe effect generalized (fight & flight)(fight & flight)

2)parasympathetic2)parasympathetic CraniosacralCraniosacral Long preganglionicLong preganglionic Short postganglionicShort postganglionic The ganglia The ganglia terminal & colateralterminal & colateral The effect localizedThe effect localized (rest & digest)(rest & digest)

From the previous discussion answer these From the previous discussion answer these questionsquestions:: Compare between somatic and autonomic nervous system ?Compare between somatic and autonomic nervous system ?

Compare between pre-ganglionic and postganglionic neurons?Compare between pre-ganglionic and postganglionic neurons?

Define the autonomic ganglia , mention its types and its Define the autonomic ganglia , mention its types and its function?function?

What are sympathetic cholinergic fibers?What are sympathetic cholinergic fibers?

Why sympathetic postganglionic fibers release norepinephrin Why sympathetic postganglionic fibers release norepinephrin but not release epinephrine?but not release epinephrine?

Explain why the sympathetic nervous system has generalized Explain why the sympathetic nervous system has generalized effects while the parasympathetic has a localized effects?effects while the parasympathetic has a localized effects?

Mention the origin of both sympathetic and parasympathetic Mention the origin of both sympathetic and parasympathetic nervous system?nervous system?

Complete: the …….ganglia is pure sympathetic while the……..is Complete: the …….ganglia is pure sympathetic while the……..is pure parasympathetic gangliapure parasympathetic ganglia

BASAL SYMPATHETIC BASAL SYMPATHETIC EFFECTSEFFECTS

AT REST (WITHOUT AT REST (WITHOUT STRESS)STRESS)

Importance of sympathetic supply to adrenal

Importance of sympathetic toneImportance of sympathetic tone DefinitionDefinition : a state of continual partial : a state of continual partial

constriction of blood vessels.constriction of blood vessels. Importance Importance : : 1- to maintain the normal blood pressure at 1- to maintain the normal blood pressure at

rest ( pressure of the blood on the wall of blood rest ( pressure of the blood on the wall of blood vessels)vessels)

2- this tone could be increased by the body to 2- this tone could be increased by the body to correct a condition of hypotension. correct a condition of hypotension.

3- this tone could be decreased by the body to 3- this tone could be decreased by the body to correct a condition of hypertensioncorrect a condition of hypertension

EFFECTS ON HEAD AND NECK EFFECTS ON HEAD AND NECK STUCTURESSTUCTURES

GENERALIZED EFFECTSGENERALIZED EFFECTSDURING STRESSDURING STRESS

HORNER”S SYNDROMEHORNER”S SYNDROME

EFFECTS ON CHEST STRUCTURESEFFECTS ON CHEST STRUCTURES

Effects on heart Effects on heart Increases heart rate (+ chronotropic )Increases heart rate (+ chronotropic ) Increases contractility (+inotropic)Increases contractility (+inotropic) Increases excitability.Increases excitability. Increases conductivityIncreases conductivity Coronary dilatation Coronary dilatation indirectlyindirectly as it increases as it increases

cardiac activity which result in increased cardiac activity which result in increased accumulation of metabolites , which in turn accumulation of metabolites , which in turn causes vasodilatation of coronariescauses vasodilatation of coronaries

Effects on the lungEffects on the lung

Bronchodilatation as it causes relaxation of Bronchodilatation as it causes relaxation of smooth muscle in the wall of bronchi.smooth muscle in the wall of bronchi.

Vasoconstriction of bronchial blood vessels.Vasoconstriction of bronchial blood vessels.

Decreases the bronchial gland secretionsDecreases the bronchial gland secretions

SYMPATHETIC EFFECTS ON SYMPATHETIC EFFECTS ON ABDOMINAL ABDOMINAL

ANDAND PELVIC STRUCTURES PELVIC STRUCTURES

PARASYMPATHETIC EFFECTSPARASYMPATHETIC EFFECTS

w

Organs with only sympathetic supplyOrgans with only sympathetic supply

Sweat gland Sweat gland Piloerector muscle Piloerector muscle Dilator pupillae muscle Dilator pupillae muscle Ventricles of the heart ( vagal escape)Ventricles of the heart ( vagal escape) Adrenal medullaAdrenal medulla Most of the blood vesselsMost of the blood vessels Kidney and reninKidney and renin

Organs with only parasympathetic Organs with only parasympathetic supply supply

Parotid glandParotid gland Lacrimal gland Lacrimal gland nasopharyngeal glands nasopharyngeal glands Constrictor pupillae muscleConstrictor pupillae muscle

Effect of autonomic supply to the Effect of autonomic supply to the pancreaspancreas

ParasympatheticParasympathetic input to the pancreatic beta cells input to the pancreatic beta cells stimulatesstimulates insulin secretion when food is first eaten. insulin secretion when food is first eaten. There is activation of parasympathetic efferents in the There is activation of parasympathetic efferents in the vagus nerve vagus nerve that stimulate insulin secretion even that stimulate insulin secretion even before there is an increase in blood glucose.before there is an increase in blood glucose.

Sympathetic inputSympathetic input to the pancreatic beta cells to the pancreatic beta cells inhibitsinhibits insulin secretion specially during insulin secretion specially during exercise as exercise as the body needs to prevent glucose uptake by non-the body needs to prevent glucose uptake by non-muscle cells (which are insulin stimulates)muscle cells (which are insulin stimulates)

AAlso the relation in the ganglia is high 1:32 to 1 ; 100