Autonomic nervous system

this will be beneficial for bsc nursing and msc nursing students

1. AUTONOMIC NERVOUS SYSTEM Presented by, Vipin Chandran 17-Mar-21 1

2. INTRODUCTION The peripheral nervous system , or PNS , consists of the cranial nerves, spinal nerves and ganglia. The peripheral nervous system subdivided into: Autonomic nervous system: sympathetic nervous system parasympathetic nervous system Somatic nervous system Enteric nervous system 17-Mar-21 2

3. The autonomic nervous system ( ANS or visceral nervous system ) is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness , and controls function. Responsible for control of “involuntary” or visceral bodily function: Cardiovascular Respiratory Digestive Urinary Reproductive functions Key role in the bodies response to stress AUTONOMIC NERVOUS SYSTEM 17-Mar-21 3

4. The autonomic nervous system (ANS) regulates the activities of cardiac muscle, smooth muscle, and glands. 17-Mar-21 4

5. It is classically divided into two subsystems : SYMPATHETIC NERVOUS SYSTEM:  Allow body to function under stress  Fight or flight  Primes body for intense skeletal muscle activity PARASYMPATHETIC NERVOUS SYSTEM  Maintenance functions  Rest-and-digest  Counter balances sympathetic function AUTONOMIC NERVOUS SYSTEM 17-Mar-21 5

6. 17-Mar-21 6

7. 17-Mar-21 7

8. In general nerve impulses from one division of the ANS stimulate the organ to increase its activity (excitation) , and another part inhibit the organs activity (inhibition) . Structurally, ANS includes: A utonomic sensory neurons (afferent) I ntegrating centers in the CNS A utonomic motor neurons (efferent) AUTONOMIC NERVOUS SYSTEM 17-Mar-21 8

9. Comparison Somatic and Autonomic Nervous System 17-Mar-21 9

10. Characteristics 1. Sensory neuron 2. Effector 3. Control of motor neuron Somatic nervous system Somatic senses and special senses Skeletal muscle Voluntary control Autonomic nervous system Mainly from interoceptors located in blood vessel, visceral organ, nervous system that monitor internal environment) Cardiac, smooth muscle and glands Involuntary control Comparison Somatic and Autonomic Nervous System 17-Mar-21 10

11. Characteristics Autonomic nervous 4. Motor neuron (efferent) pathway Somatic nervous system One motor axon from CNS to effector system Two neuron pathway: One motor axon from CNS to autonomic ganglion (preganglionic) One motor axon from autonomic ganglion to effector (postganglionic) 17-Mar-21 11

12. 17-Mar-21 12

13. 17-Mar-21 13

14. EFFECTS OF SYMPATHETIC NERVOUS SYSTEM The sympathetic system prepares the body to meet emergency demands and is primarily involved with processes that expend energy . During physical or emotional stress, the sympathetic division dominates the parasympathetic system, initiating a series of activities known as the fight-or-flight response . In addition, there is activation of the adrenal medulla, causing secretion of norepinephrine and epinephrine as hormones to greatly heighten the response. 17-Mar-21 14

15. Cardiovascular System Increasing heart beat Increase blood supply to cardiac muscle (dilate the coronary artery) Constrict the blood vessel in secretory glands of digestive system Accelerates blood coagulation because of vasoconstriction. 17-Mar-21 15

16. Respiratory system Causes smooth muscle relaxation and therefore dilatation of the airways, especially bronchioles. Allowing a greater amount of air to enter the lungs at each inspiration, and increase the respiratory rate. Deal with ' fight and flight ' situation. 17-Mar-21 16

17. Digestive and urinary system Liver increase conversion of glycogen to glucose Stomach and small intestine; smooth muscle contraction (peristalsis) and secretion of digestive juices are inhibited . Adrenal gland; stimulated to secrete adrenaline and noradrenaline which potentiate and sustain the effect of sympathetic stimulation Urethral and anal sphincter; muscle tone increase, inhibit micturition and defecation. Bladder walls relaxes Metabolic rate increase 17-Mar-21 17

18. Eye Dilating the pupil Opening the eyes open wide and giving the appearance of alertness and excitement Skin Increase sweat secretion, leading to increased heat loss from the body Contract the arrector pili muscle on the skin Constrict the peripheral blood vessel increasing blood supply available to active organs, e.g heart and skeletal muscle. 17-Mar-21 18

19. The parasympathetic nervous system is an energy conservation-restorative system. It regulates those activities that conserve and restore body energy during times of rest and digest. The parasympathetic nervous system dominates over sympathetic activity in the glands and smooth muscle of the gut, stimulating glandular secretion and the gut movements necessary for food to be digested and absorbed. Salivation, lacrimation, urination, and defecation, all controlled by the parasympathetic nervous system. EFFECTS OF PARASYMPATHETIC NERVOUS SYSTEM 17-Mar-21 19

20. Cardiovascular System Decrease the rate and force of the heartbeat Constrict the coronary artery reducing the blood supply to cardiac muscle Respiratory Produces contraction of smooth muscle in airway walls causing their constriction, e.g. bronchioles and bronchi Eye Constricting the pupil The eyelids tend to closed, giving the appearance of sleepiness. 17-Mar-21 20

21. Digestive and urinary system Liver: conversion of glucose to glycogen and secretion of bile are increased. Stomach and small intestine: Motility and secretion are increased together with the rate of digestion and absorption of food. Pancreas: secretion of pancreatic juice and the hormone insulin are increase. Urethral and anal sphincter: relaxation in urethral and anal sphincter, micturition and defecation occurs. 17-Mar-21 21

22. 17-Mar-21 22

23. 17-Mar-21 23