Presentation is loading. Please wait.

Presentation is loading. Please wait.

Physiology of autonomic nervous system. Autonomic Nervous System 2 divisions: 2 divisions: Sympathetic Sympathetic “Fight or flight” “Fight or flight”

Similar presentations


Presentation on theme: "Physiology of autonomic nervous system. Autonomic Nervous System 2 divisions: 2 divisions: Sympathetic Sympathetic “Fight or flight” “Fight or flight”"— Presentation transcript:

1 Physiology of autonomic nervous system

2

3 Autonomic Nervous System 2 divisions: 2 divisions: Sympathetic Sympathetic “Fight or flight” “Fight or flight” “E” division “E” division Exercise, excitement, emergency, and embarrassment Exercise, excitement, emergency, and embarrassment Parasympathetic Parasympathetic “Rest and digest” “Rest and digest” “D” division “D” division Digestion, defecation, and diuresis Digestion, defecation, and diuresis

4

5

6

7 Function Sympathetic and parasympathetic divisions typically function in opposition to each other. But this opposition is better termed complementary in nature rather than antagonistic. For an analogy, one may think of the sympathetic division as the accelerator and the parasympathetic division as the brake. The sympathetic division typically functions in actions requiring quick responses. The parasympathetic division functions with actions that do not require immediate reaction. Consider sympathetic as "fight or flight" and parasympathetic as "rest and digest". Sympathetic and parasympathetic divisions typically function in opposition to each other. But this opposition is better termed complementary in nature rather than antagonistic. For an analogy, one may think of the sympathetic division as the accelerator and the parasympathetic division as the brake. The sympathetic division typically functions in actions requiring quick responses. The parasympathetic division functions with actions that do not require immediate reaction. Consider sympathetic as "fight or flight" and parasympathetic as "rest and digest".

8

9

10 Autonomic nervous system Autonomic nervous system sympathetic nervous system: sympathetic trunks (white ramus communicans, gray ramus communicans) - collateral ganglia sympathetic nervous system: sympathetic trunks (white ramus communicans, gray ramus communicans) - collateral ganglia sympathetic nervous systemsympathetic trunkswhite ramus communicansgray ramus communicanscollateral ganglia sympathetic nervous systemsympathetic trunkswhite ramus communicansgray ramus communicanscollateral ganglia cavernous plexus - cervical ganglia: (superior, middle, inferior) - splanchnic nerves: (thoracic, lumbar, sacral) - ganglion impar cavernous plexus - cervical ganglia: (superior, middle, inferior) - splanchnic nerves: (thoracic, lumbar, sacral) - ganglion impar cavernous plexussuperiormiddle inferiorthoraciclumbarsacral ganglion impar cavernous plexussuperiormiddle inferiorthoraciclumbarsacral ganglion impar internal carotid - cardiac internal carotid - cardiac internal carotidcardiac internal carotidcardiac celiac: celiac ganglia - aorticorenal - renal - spermatic/ovarian - superior mesenteric - aortic plexus - inferior mesenteric - hepatic - splenic - gastric - pancreatic - suprarenal celiac: celiac ganglia - aorticorenal - renal - spermatic/ovarian - superior mesenteric - aortic plexus - inferior mesenteric - hepatic - splenic - gastric - pancreatic - suprarenal celiac gangliaaorticorenalrenalspermaticovariansuperior mesentericaortic plexusinferior mesenteric hepaticsplenicgastricpancreaticsuprarenal celiac gangliaaorticorenalrenalspermaticovariansuperior mesentericaortic plexusinferior mesenteric hepaticsplenicgastricpancreaticsuprarenal hypogastric: superior hypogastric - inferior hypogastric - vesical - prostatic - uterovaginal hypogastric: superior hypogastric - inferior hypogastric - vesical - prostatic - uterovaginalsuperior hypogastricinferior hypogastric vesicalprostaticuterovaginalsuperior hypogastricinferior hypogastric vesicalprostaticuterovaginal parasympathetic nervous system: ciliary ganglion (short ciliary nerves) - pterygopalatine ganglion (nerve of pterygoid canal) - submandibular ganglion - otic ganglion - pelvic splanchnic parasympathetic nervous system: ciliary ganglion (short ciliary nerves) - pterygopalatine ganglion (nerve of pterygoid canal) - submandibular ganglion - otic ganglion - pelvic splanchnicciliary ganglionshort ciliary nervespterygopalatine ganglionnerve of pterygoid canalsubmandibular ganglionotic ganglionpelvic splanchnicciliary ganglionshort ciliary nervespterygopalatine ganglionnerve of pterygoid canalsubmandibular ganglionotic ganglionpelvic splanchnic

11 Receptors The parasympathetic nervous system uses only acetylcholine (ACh) as its neurotransmitter. The ACh acts on two types of receptors, the muscarinic and nicotinic cholinergic receptors. Most transmissions occur in two stages: When stimulated, the preganglionic nerve releases ACh at the ganglion, which acts on nicotinic receptors of the postganglionic nerve. The postganglionic nerve then releases ACh to stimulate the muscarinic receptors of the target organ. The parasympathetic nervous system uses only acetylcholine (ACh) as its neurotransmitter. The ACh acts on two types of receptors, the muscarinic and nicotinic cholinergic receptors. Most transmissions occur in two stages: When stimulated, the preganglionic nerve releases ACh at the ganglion, which acts on nicotinic receptors of the postganglionic nerve. The postganglionic nerve then releases ACh to stimulate the muscarinic receptors of the target organ. acetylcholineneurotransmittermuscarinic nicotiniccholinergic preganglionic postganglionic acetylcholineneurotransmittermuscarinic nicotiniccholinergic preganglionic postganglionic

12 Neurotransmitters and pharmacology At the effector organs, sympathetic ganglionic neurons release noradrenaline (norepinephrine) to act on adrenergic receptors, with the exception of the sweat glands and the adrenal medulla: At the effector organs, sympathetic ganglionic neurons release noradrenaline (norepinephrine) to act on adrenergic receptors, with the exception of the sweat glands and the adrenal medulla: noradrenalineadrenergic receptors noradrenalineadrenergic receptors At sweat glands, the neurotransmitter is acetylcholine, which acts on muscarinic receptors. At sweat glands, the neurotransmitter is acetylcholine, which acts on muscarinic receptors.sweat glandsmuscarinic receptorssweat glandsmuscarinic receptors At the adrenal cortex, there is no postsynapic neuron. Instead the presynaptic neuron releases acetylcholine to act on nicotinic receptors. At the adrenal cortex, there is no postsynapic neuron. Instead the presynaptic neuron releases acetylcholine to act on nicotinic receptors.adrenal cortex nicotinic receptorsadrenal cortex nicotinic receptors Stimulation of the adrenal medulla releases adrenaline (epinephrine) into the bloodstream which will act on adrenoceptors, producing a widespread increase in sympathetic activity. Stimulation of the adrenal medulla releases adrenaline (epinephrine) into the bloodstream which will act on adrenoceptors, producing a widespread increase in sympathetic activity.adrenal medullaadrenalineadrenal medullaadrenaline In the parasympathetic system, ganglionic neurons use acetylcholine as a neurotransmitter, to stimulate muscarinic receptors. In the parasympathetic system, ganglionic neurons use acetylcholine as a neurotransmitter, to stimulate muscarinic receptors.muscarinic receptorsmuscarinic receptors

13 SympatheticSympathetic (adrenergic, with exceptions) adrenergic Sympatheticadrenergic cardiac output increases cardiac output increases cardiac output cardiac output SA node: heart rate (chronotropic)β1, β2: increases SA node: heart rate (chronotropic)β1, β2: increases SA nodechronotropic SA nodechronotropic cardiac muscle: contractility (inotropic)β1, β2: increases cardiac muscle: contractility (inotropic)β1, β2: increases cardiac muscleinotropic cardiac muscleinotropic conduction at AV nodeβ1: increases conduction at AV nodeβ1: increasesAV nodeAV node vascular smooth muscle M3: contracts; α = contracts; β2 = relaxes vascular smooth muscle M3: contracts; α = contracts; β2 = relaxes vascular smooth muscle vascular smooth muscle smooth muscles of bronchiolesβ2: relaxes (major contribution); α1: contracts (minor contribution) smooth muscles of bronchiolesβ2: relaxes (major contribution); α1: contracts (minor contribution) smooth musclesbronchioles smooth musclesbronchioles pupil of eyeα1: relaxes pupil of eyeα1: relaxes pupileye pupileye ciliary muscleβ2: relaxes ciliary muscleβ2: relaxes ciliary muscle ciliary muscle salivary glands: secretionsβ: stimulates viscous, amylase secretions; α1 = stimulates potassium cation salivary glands: secretionsβ: stimulates viscous, amylase secretions; α1 = stimulates potassium cation salivary glandsamylasepotassium salivary glandsamylasepotassium smooth muscles of GI tractα, β2: relaxes smooth muscles of GI tractα, β2: relaxes smooth musclesGI tract smooth musclesGI tract sphincters of GI tractα1: contracts sphincters of GI tractα1: contracts sphinctersGI tract sphinctersGI tract glands of GI tractinhibits glands of GI tractinhibits glandsGI tract glandsGI tract

14 ParasympatheticParasympathetic (muscarinic) muscarinic Parasympatheticmuscarinic cardiac output M2: decreases cardiac output M2: decreases cardiac output cardiac output SA node: heart rate (chronotropic) M2: decreases SA node: heart rate (chronotropic) M2: decreases SA nodechronotropic SA nodechronotropic cardiac muscle: contractility (inotropic) M2: decreases (atria only) cardiac muscle: contractility (inotropic) M2: decreases (atria only) cardiac muscleinotropicatria cardiac muscleinotropicatria conduction at AV node M2: decreases conduction at AV node M2: decreasesAV nodeAV node smooth muscles of bronchioles M3: contracts smooth muscles of bronchioles M3: contracts smooth musclesbronchioles smooth musclesbronchioles pupil of eye M3: contracts pupil of eye M3: contracts pupileye pupileye ciliary muscle M3: contracts ciliary muscle M3: contracts ciliary muscle ciliary muscle salivary glands: secretions stimulates watery secretions salivary glands: secretions stimulates watery secretions salivary glands salivary glands GI tract motility M1, M3: increases GI tract motility M1, M3: increases GI tract GI tract smooth muscles of GI tract M3: contracts smooth muscles of GI tract M3: contracts smooth musclesGI tract smooth musclesGI tract sphincters of GI tract M3: relaxes sphincters of GI tract M3: relaxes sphinctersGI tract sphinctersGI tract glands of GI tract M3: secretes glands of GI tract M3: secretes glandsGI tract glandsGI tract

15 Autonomic regulation & stress A stressful situation activates three major communication systems in the brain that regulate bodily functions. A stressful situation activates three major communication systems in the brain that regulate bodily functions. The first of these systems is the voluntary nervous system, which sends messages to muscles so that we may respond to sensory information. The first of these systems is the voluntary nervous system, which sends messages to muscles so that we may respond to sensory information. The second communication system is the autonomic nervous system. It combines the sympathetic or emergency branch, which gets us going in emergencies, and the parasympathetic or calming branch, which keeps the body’s maintenance systems, such as digestion, in order and calms the body’s responses to the emergency branch. The second communication system is the autonomic nervous system. It combines the sympathetic or emergency branch, which gets us going in emergencies, and the parasympathetic or calming branch, which keeps the body’s maintenance systems, such as digestion, in order and calms the body’s responses to the emergency branch. The brain’s third major communication process is the neuroendocrine system, which also maintains the body’s internal functioning. The brain’s third major communication process is the neuroendocrine system, which also maintains the body’s internal functioning.

16 Each of these systems has a specific task The emergency branch causes arteries supplying blood to the muscles to relax in order to deliver more blood, allowing greater capacity to act. At the same time, the emergency system reduces blood flow to the skin, kidneys, and digestive tract and increases blood flow to the muscles. The emergency branch causes arteries supplying blood to the muscles to relax in order to deliver more blood, allowing greater capacity to act. At the same time, the emergency system reduces blood flow to the skin, kidneys, and digestive tract and increases blood flow to the muscles. In contrast, the calming branch helps to regulate bodily functions and soothe the body once the stressor has passed, preventing the body from remaining too long in a state of mobilization. Left mobilized and unchecked, these body functions could lead to disease. Some actions of the calming branch appear to reduce the harmful effects of the emergency branch’s response to stress. In contrast, the calming branch helps to regulate bodily functions and soothe the body once the stressor has passed, preventing the body from remaining too long in a state of mobilization. Left mobilized and unchecked, these body functions could lead to disease. Some actions of the calming branch appear to reduce the harmful effects of the emergency branch’s response to stress. Various “stress hormones” travel through the blood and stimulate the release of other hormones, which affect bodily processes such as metabolic rate and sexual functions. Various “stress hormones” travel through the blood and stimulate the release of other hormones, which affect bodily processes such as metabolic rate and sexual functions.

17 THE STRESS REACTION THE STRESS REACTION When stress occurs, the sympathetic nervous system is triggered. Norepinephrine is released by nerves, and epinephrine is secreted by the adrenal glands. By activating receptors in blood vessels and other structures, these substances ready the heart and working muscles for action. When stress occurs, the sympathetic nervous system is triggered. Norepinephrine is released by nerves, and epinephrine is secreted by the adrenal glands. By activating receptors in blood vessels and other structures, these substances ready the heart and working muscles for action. Acetylcholine is released in the parasympathetic nervous system, producing calming effects. The digestive tract is stimulated to digest a meal, the heart rate slows, and the pupils of the eyes become smaller. The neuroendocrine system also maintains the body’s normal internal functioning. Acetylcholine is released in the parasympathetic nervous system, producing calming effects. The digestive tract is stimulated to digest a meal, the heart rate slows, and the pupils of the eyes become smaller. The neuroendocrine system also maintains the body’s normal internal functioning.

18 Chronic stress When glucocorticoids or adrenaline are secreted in response to the prolonged psychological stress commonly encountered by humans, the results are not ideal. Normally, bodily systems gear up under stress and release hormones to improve memory, increase immune function, enhance muscular activity, and restore homeostasis. If you are not fighting or fleeing, but standing frustrated in a supermarket checkout line or sitting in a traffc jam, you are not engaging in muscular exercise. When glucocorticoids or adrenaline are secreted in response to the prolonged psychological stress commonly encountered by humans, the results are not ideal. Normally, bodily systems gear up under stress and release hormones to improve memory, increase immune function, enhance muscular activity, and restore homeostasis. If you are not fighting or fleeing, but standing frustrated in a supermarket checkout line or sitting in a traffc jam, you are not engaging in muscular exercise. Yet these systems continue to be stimulated, and when they are stimulated chronically, there are different consequences: Memory is impaired, immune function is suppressed, and energy is stored as fat. Yet these systems continue to be stimulated, and when they are stimulated chronically, there are different consequences: Memory is impaired, immune function is suppressed, and energy is stored as fat.

19 Response to stress


Download ppt "Physiology of autonomic nervous system. Autonomic Nervous System 2 divisions: 2 divisions: Sympathetic Sympathetic “Fight or flight” “Fight or flight”"

Similar presentations


Ads by Google