Autonomic NS Notes - Lecture 4 (General Physiology- Nursing)

General Physiology- Nursing Autonomic Nervous System Prof Dr. Abeer Foad Lecture Objectives At the end of this lecture you will be able to: 1) Identify the origin of sympathetic supply to different regions of the body 2) Describe the functions of sympathe...

General Physiology- Nursing Autonomic Nervous System Prof Dr. Abeer Foad Lecture Objectives At the end of this lecture you will be able to: 1) Identify the origin of sympathetic supply to different regions of the body 2) Describe the functions of sympathetic stimulations to head and neck, thorax, abdomen and pelvis 3) Identify the origin of parasympathetic supply to different regions of the body 4) Describe the functions of parasympathetic stimulations to head and neck, thorax, abdomen and pelvis 5) Identify the actions of the different parts of autonomic NS Contents 01 sympathetic supply to head and neck 02 sympathetic supply to thorax, abdomen and pelvis 03 Cranial part of parasympathetic NS 04 Sacral division of parasympathetic NS 05 Functions of autonomic NS in different conditions  Nervous System NS is the major control system in the body (regulates many body functions) 5  Reflex Action Def.:  It is an involuntary reaction of the body to a sensory stimulus  It is carried out through a reflex arc The components of reflex arc: 1.Receptors. 2.Afferent (sensory) neuron 3.Center (in CNS). 4.Efferent (motor) neuron 5.Effectors (muscles or glands). Types: i) Somatic reflex ;e.g. flexion withdrawal reflex. ii) Autonomic reflex; e.g. micturition reflex. Components of Reflex Arc Types of Reflex Action  Divisions of Nervous System PNS CNS Anatomical division Functional division Physiological division  12 pairs Cranial  Afferent (sensory) nerve  Somatic N S  31 pairs Spinal  Efferent (motor) nerve  Autonomic NS  Somatic N.S Autonomic N.S. Control Voluntary functions e.g. walking Involuntary functions e.g. heart rate Chemical - Acetylcholine - Acetylcholine transmitters - Nor epinephrine Motor nerve - One neuron. -Two neurons. fibers - No ganglia - Presence of ganglia - Thick myelinated nerve fibers (type - Preganglionic is thin myelinated nerve fibers A). Innervates skeletal muscles, joints (type B) & skin -Postganglionic is non-myelinated nerve fibers (type C). Innervates smooth & cardiac muscles, glands  Autonomic NS Def. Part of the PNS supplies and regulates the functions of internal organs. Divisions of ANS ANS is subdivided into 2 systems: A. Sympathetic (thoracolumbar) NS B. Parasympathetic (craniosacral) NS 11  Autonomic of Ganglia Def., Are collection of cell bodies of neurons outside the central nervous system (CNS) Functions: Act as a relay station for autonomic preganglionic nerve fibers  Autonomic of Ganglia Types: a) Lateral (Paravertebral) ganglia: Located on either side of the spinal cord Act as a relay station for sympathetic fibers only b) Collateral (Prevertebral) ganglia: Present mainly in the abdomen Act as a relay station for sympathetic fibers c) Terminal ganglia: Present close to or at the wall of the effector organs especially pelvic organs Act as a relay station of: a) All parasympathetic preganglionic fibers b) Some sympathetic preganglionic fibers Sympathetic NS Origin of Sympathetic N.S.(thoracolumbar) : 1. All thoracic segments (T1 – T12) 2. Upper 3 lumbar segments of the spinal cord (L1, L2, L3) 14  Functions of Sympathetic N.S. Mydriasis 1) Eye: a) Dilatation of pupil (Mydriasis) b) Exophthalmos. c) Helps the eye to see far objects Exophthalmos 15  Functions of Sympathetic N.S. 2) Salivary Glands: a) Vasoconstriction (V.C.) of blood vessels b) Trophic secretions: little, viscous, poor in water, rich in enzymes 3) Skin: a) V.C of skin blood vessels. b) Hair erection c) Sweat secretion. 16  Functions of Sympathetic N.S. 4) Heart: 5) Lungs: a) ↑ the heart rate and force of contraction a) Bronchodilatation. b) Vasodilatation of coronary vessels b) Decreases mucus secretion of air passages 17  Functions of Sympathetic N.S. 6) GIT & Gall bladder : relaxation of their walls and contraction of their sphincters 7) Pancreas: inhibits its secretion. 8) Spleen: Contraction → pouring of about 250 ml of blood into the general circulation. 9) Suprarenal medulla Secretion of adrenaline and noradrenalin 10) Kidneys: Decreases renal blood flow and urine output. 18  Functions of Sympathetic N.S. 11) Urinary bladder: It causes relaxation of its wall and contraction of the internal urethral sphincter → retention of urine. 12) Rectum: It causes relaxation of its wall and contraction of the internal anal sphincter → retention of feces. 19 Parasympathetic N.S. Origin of Parasympathetic (craniosacral ) : A) Cranial part: 1.Oculomotor N. 2.Facial N. 3.Glossopharyngeal N. 4.Vagus nerve B) Sacral part: S2,S3,S4 and forms pelvic nerve 21  Oculomotor N. Functions a)Constriction of the pupil (Miosis) b)Helps the eye to see near objects. Miosis 22  Facial N. Functions a.Lacrimal glands: i) Vasodilatation. ii) Secretion of tears. b. Submandibular and sublingual salivary glands: i. Vasodilatation. ii. True salivary secretion (large in volume, watery, rich in electrolytes, and poor in enzymes). 23  Glossopharyngeal N. Otic G. MO Parotid Salivary Gland Functions i) Vasodilatation. ii) True salivary secretion (large in volume, watery, rich in electrolytes, and poor in enzymes) 24 Vagus N. 25  Vagus N. functions 1) Heart: a) ↓es the heart rate and force of contraction b) VC of coronary vessels 2) Lungs: a) Bronchoconstriction. b) ↑es the mucus secretion of the air passages. 26  Vagus Vagus N. functions N. 3) GIT Contraction of their walls and relaxation of their sphincters 4) Gall bladder: Contraction of its wall and relaxation of the sphincter 5) Liver: Stimulate bile secretion 6) Pancreas: Stimulates its secretion. 7) Blood vessels: VD 27  Sacral Outflow: Pelvic N. Functions: 1. Urinary bladder: Contraction of its wall and contraction of internal urethral sphincter → micturition 2. Rectum : Contraction of its wall and contraction of internal anal sphincter → defecation 28  Questions 1-Which of the following is a part of 2- The autonomic nervous system is PNS: characterized by; a) Cerebrum a) Control of voluntary functions b) Pons b) Supply joints and skeletal muscles c) Cerebellum c) No ganglia d) Spinal nerves d) Consists of 2 neurons 3- Which of the following structures is NOT 4- The autonomic ganglia; a component of reflex arc? a) Are 5 types. a) Sensory neuron. b) Present in both somatic and autonomic NS b) Motor neuron. c) Function as relay stations for preganglionic c) Ligand-gated ion channels nerve fibers. d) Sensory receptor d) Are located inside the CNS.  Questions 1.The function of parasympathetic 3. Sympathetic stimulation of heart causes innervation to the salivary glands is: a) Increase in heart rate a) VC & trophic secretion. b) Coronary vasoconstriction b) VD & tropic secretion c) Decrease in force of contraction of the heart c) VD & true secretion. d) Bronchodilatation d) VC & true secretion 3.The autonomic ganglia; a) Are 5 types. b) Are present in both somatic and autonomic nervous systems c) Function as relay station for preganglionic nerve fibers. d) Are located inside the CNS. THANK YOU