Physiology - Autonomic Nervous System - Fall 2023 - Galala University PDF

F A C U L T Y O F P h a r m a c y F A L L 2 0 2 3 Faculty of Pharmacy Physiology AUTONOMIC NERVOUS SYSTEM 1 Dr. Doaa Abdel Wahed Lecturer of Physiology...

F A C U L T Y O F P h a r m a c y F A L L 2 0 2 3 Faculty of Pharmacy Physiology AUTONOMIC NERVOUS SYSTEM 1 Dr. Doaa Abdel Wahed Lecturer of Physiology Faculty of Medicine 2 Faculty of Pharmacy Intended Learning Outcomes - By the end of this lecture, you should be able to: 1. Define the nervous system and identify its general organization. 2. Identify the differences between somatic nervous system & autonomic nervous system. 3. Know the divisions of autonomic nervous system. 4. Identify the anatomical origin of ANS divisions. 5. Study the function of sympathetic and parasympathetic nervous system in the body. 3 Faculty of Pharmacy The Nervous System - The Nervous System is the master controlling and communicating system of the body. - It transmits impulses to every organ in the body to control its activity. 4 Faculty of Pharmacy General organization of nervous system Nervous System Central Nervous Peripheral System Nervous System Brain Spinal Cord Somatic Autonomic Sympathetic Parasympathetic 5 Faculty of Pharmacy Divisions of the peripheral Nervous System -Peripheral Nervous System is divided into: Somatic Division: the effector organ is a skeletal muscle. Autonomic Divisions :the effector organ is cardiac, smooth muscles, glands. 6 Faculty of Pharmacy Somatic Versus autonomic nervous system 7 Faculty of Pharmacy Neurons (Nerve Cells) ✓ Nerve Cell is the structural and functional unit of the nervous system. ✓ Composed of a body, axon and dendrites. 8 Faculty of Pharmacy Autonomic nervous system Autonomic nervous system (ANS) is responsible for regulation of visceral functions of the body. So, it is also called involuntary nervous system. 9 Faculty of Pharmacy Divisions of Autonomic nervous system(ANS) Sympathetic nervous system ANS Parasympathetic nervous system 10 Faculty of Pharmacy Divisions of nervous system ????? Somatic vs autonomic nervous system ????? Divisions of ANS ????? 11 Faculty of Pharmacy 12 Faculty of Pharmacy Sympathetic Nervous System Faculty of Pharmacy Anatomical origin of Sympathetic Thoracic segments nervous system T1-T12 (Thoraco-lumbar) (Thoracolumbar) Lumber (T1 – L3) (L1-L3) 14 Faculty of Pharmacy Sympathetic Nervous System Branches Nerve to Cervical Cardiopulmonary Splanchnic pelvis Faculty of Pharmacy Functions of Sympathetic Nervous System I-Cervical division: (1) Eye: Contraction of dilator pupillae muscle ----> dilatation of pupil (mydriasis). Contraction of tarsal muscles ----> widening of palpebral fissures. Relaxation of ciliary muscles ----> for far vision. Contraction of Muller’s muscle ----> forward protrusion of eyeball (exophthalmos) esp. in animals. Vasoconstriction (VC) of ocular blood vessels. 17 Faculty of Pharmacy (2) Salivary glands: VC of salivary blood vessels. Secretion of viscous saliva. (3) Skin: VC of skin blood vessels. Secretion of sweat. Erection of hair by contraction of erector pillae muscles. Faculty of Pharmacy II-Cardio-Pulmonary division: (1) Heart: It increases all properties of the cardiac muscles, cardiac acceleration (+ ve chronotropic) and increase contractility (+ ve inotropic), increase conductivity and increase excitability. Vasodilatation (VD) of coronary vessels. (2) Lung: Bronchodilatation, by relaxation of bronchial wall smooth muscles. VC of pulmonary blood vessels. Faculty of Pharmacy III-Splanchnic division: 1- Relaxation of walls of stomach & intestine & contraction of their sphincters leading to retention of food. 2- Decreased gastric and intestinal motility. 3- Inhibition of intestinal secretion. 4- Stimulate glycogenolysis (glycogen breakdown in liver). 5- Stimulate lipolysis (lipids breakdown in liver). 6- Relaxation of gall bladder & contraction of its sphincter. 7- Contraction of smooth muscle in the splenic capsule (to squeeze the stored blood). 8- VC of visceral blood vessels. Faculty of Pharmacy IV-Sympathetic supply to the pelvis: Urinary bladder: inhibition of the wall of the bladder and contraction of the internal urethral sphincter leading to retention of urine. Rectum: inhibition of the wall of the rectum and contraction of the internal anal sphincter leading to retention of feces. Faculty of Pharmacy Parasympathetic Nervous System Faculty of Pharmacy Cranial division Anatomical origin of Parasympathetic nervous system (Craniosacral) Cranial nerves (III, VII, IX, & X), S2–S4 Sacral division(S2- S4) 23 Faculty of Pharmacy Parasympathetic Nervous System Branches Cranial Sacral Occulomotor (III) Facial (VII) Glosssopharyngeal (IX) Vagus (X) Faculty of Pharmacy Functions of the Parasympathetic System (A)The cranial outflow: l) The occulomotor nerve (3rd cranial nerve): 1- Contraction of constrictor pupillae muscle produces miosis. 2- Contraction of ciliary muscle → increase convexity of lens to allow increase lens power for near vision. Faculty of Pharmacy 2) The facial nerve (7th cranial n.): 1- Secretion of profuse watery saliva. 2- VD of blood vessels of salivary glands. 3) Glossopharyngeal nerve (9th cranial n.): - Secretion of parotid gland & VD of blood vessels. - Secretion of glands of posterior 1/3 of the tongue. Faculty of Pharmacy 4) The vagus nerve (10th cranial n.): 1-In the heart: inhibits all cardiac properties, decrease the heart rate, decrease the contractility of cardiac muscles. VC of coronary blood vessels 2- Lungs: Bronchoconstriction. VD of blood vessels. 3- GIT: Contraction of gall bladder. Contraction of wall of stomach & intestine & inhibition of sphincters → help evacuation of food. Secretory to stomach, pancreas, liver for digestion. Faculty of Pharmacy (B)The sacral outflow: 1-Urinary bladder: Motor (stimulatory) to the wall and inhibitory to internal urethral sphincter → help micturition. 2-Colon and rectum: Motor to the wall and inhibitory to their sphincters→ help defecation. Faculty of Pharmacy Sympathetic Versus Parasympathetic Nervous System 29 Faculty of Pharmacy Origin of sympathetic & parasympathetic nervous system ????? Functions of sympathetic nervous system ???? Functions of parasympathetic nervous system????? 30 Faculty of Pharmacy 31 Faculty of Pharmacy