Autonomic Nervous System. Part of the nervous system that controls most of the visceral functions of the body ( Automatically?

Transcription

1 Autonomic Response?

2 Autonomic Nervous System Part of the nervous system that controls most of the visceral functions of the body ( Automatically?)

3 Classification Of CNS

4 Autonomic Nervous System Visceral functions Heart and blood pressure GIT motility & secretions Urinary bladder emptying Sweating & body temperature regulation Bronchodilation and Constriction Muscle blood flow Rapidity & Intensity Functions within seconds

5 Typical Spinal Nerve

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9 Basic Characteristics Cholinergic & Adrenergic Fibers

10 Sympathetic Parasympathetic Cholinergic Cholinergic Cholinergic Sweat Glands, Piloerector Muscle, A few Blood Vessels Adrenergic Cholinergic

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12 Metabolism of Neurotransmitters Acetylcholine Synthesis From Choline In terminal nerve endings Destruction (enzyme) Acetylcholinesterase Norepinephrine Synthesis From Tyrosine In axoplasm of nerve endings Removal i. Reuptake ii. Blood iii.enzymes (MAO)

13 Circulation of neurotransmitters Acetylcholine: Local Noradrenalin/ Norepinephrine: Local Blood Adrenalin/ Epinephrine Blood Hormone

14 Synthesis & Release of Acetylcholine

15 General Rule: Function of the autonomic nerves is dependent on the type of receptor present on the postsynaptic membrane

16 Autonomic Receptors Receptors Cholinergic Adrenergic Muscarinic Nicotinic Alpha Beta Alpha 1 Alpha 2 Beta 1 Beta 2 Beta 3

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18 Organs Receiving only Sympathetic Innervation Adrenal Medulla Kidney Pilo-erector muscles (Cholinergic) Sweat glands (Cholinergic) Vessels Metabolic processes

19 Sympathetic functions

20 Parasympathetic functions

21 Autonomic functions Organ Parasympathetic Sympathetic EYE 1. Miosis 2. Near Accommodation 1. Mydriasis 2. Opposite HEART 1. Heart rate 2. force of contraction 3. Conduction of velocity Opposite (ß-1 receptors) BLOOD VESSELS 1. Dilation? 1. Alpha receptors: Constriction 2. ß-2 receptors : Dilatation e.g. Coronary arteries, skeletal muscles

22 Organ Parasympathetic Sympathetic Lungs 1. Muscle contraction 2. secretion GIT Stomach, Intestine 1. Motility 2. Secretions 3. Sphincters relaxed Gall Bladder/Ducts: Contraction Opposite(ß-2) Opposite URINARY BLADDER 1. Muscle Contraction 2. Sphincter relaxed Opposite MTABOLISM 1. Anabolism Catabolism (ß receptors) glycogenolysis lipolysis BMR

23 Organ Parasympathetic Sympathetic Kidney Nil Renin Mental activity Nil Skeletal Muscle Nil Glycogenolysis Stretch

24 Physiological Differences B/W Adrenaline & Nor-Adrenaline Adrenalin (Epinephrine). 1. Greater effect on beta Receptors- Greater efffect on Heart. 2. Weak vasoconstrictor in Muscles, hence rise in TPR is less But Increase more COP time more effect on tissue metabolism than Nor-epinephrine Nor-adrenalin(Nor-Epi) 1.Less effect on Heart stimulation 2. Strong Constriction in Muscles, Hence increase in TPR is more -> Rise in BP 3. Less effect on tissue metabloism

25 Autonomic Functions Opposite to each other Excitatory / Inhibitory Parasympathetic: Localized Sympathetic: Diffuse

26 mass discharge Almost all portions of the sympathetic nervous system discharge simultaneously as a complete unit, a phenomenon called mass discharge. occurs when the hypothalamus is activated by fright or severe pain. The result is a widespread reaction throughout the body called the alarm or stress response At other times, activation occurs in isolated portions of the sympathetic nervous system

27 ALARM OR STRESS RESPONSE OF THE SYMPATHETIC NERVOUS SYSTEM Increased arterial pressure with decreased blood flow to organs such as the gastrointestinal tract and the kidneys that are not needed for rapid motor activity Increased rates of cellular metabolism throughout the body Increased blood glucose concentration Increased glycolysis in the liver and in muscle Increased muscle strength Increased mental activity Increased rate of blood coagulation

28 The Parasympathetic System Usually Causes Specific Localized Responses parasympathetic cardiovascular reflexes usually act only on the heart to increase or decrease its rate of beating parasympathetic reflexes cause secretion mainly by the mouth glands -- other instances secretion is by the stomach glands. the rectal emptying reflex does not affect other parts of the bowel to a major extent rectal emptying reflex often initiates a urinary bladder emptying reflex

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