Autonomic Nervous System 5 Lecture Notes PDF

Field of Medicine Medicine Program Lecture : (Autonomic Nervous System 5 ) Dr : (Mohamed Talal) Date: / 10 / 2024 Parasympathetic nervous system Effect on thorax and abdomen : vagus nerve : ( 10th cranial nerve ) origin : vagal nucleus in medulla relay : terminal ganglia Acti...

Field of Medicine Medicine Program Lecture : (Autonomic Nervous System 5 ) Dr : (Mohamed Talal) Date: / 10 / 2024 Parasympathetic nervous system Effect on thorax and abdomen : vagus nerve : ( 10th cranial nerve ) origin : vagal nucleus in medulla relay : terminal ganglia Action : on Thorax Heart -ve inotropic effect -ve chronotropic effect decrease coronary blood flow and O2 consumption Lung bronchial constriction vasodilatation of pulmonary blood vessels Parasympathetic nervous system Effect on thorax and abdomen : vagus nerve : ( 10th cranial nerve ) Action : on abdomen GIT : motor to the wall inhibitory to sphincters gall bladder : ( evacuation ) motor to the wall inhibitory to sphincter of oddi Parasympathetic nervous system Effect on pelvis : Origin: S2, 3, 4 Course: pelvic nerve Relay: terminal ganglia On the rectum : (defecation ) contraction of wall inhibition of internal anal sphincter Parasympathetic nervous system Effect on pelvis : on the urinary bladder : ( micturition ) contraction of wall inhibition of internal urethral sphincter On male genitalia : erection Neurotransmitters of parasympathetic nervous system Chemical neurotransmitters : Acetylcholine Neurotransmitters of autonomic nervous system parasympathetic nervous system: Acetyl choline : Formation: Acetate + Co-enzyme A Acetyl Co-A + choline Acetyl choline parasympathetic nervous system: Acetyl choline : Removal: By choline esterase enzyme parasympathetic nervous system: Nicotinic receptors : Site : Autonomic ganglia Stimulated by : Nicotine small dose – anti-choline esterase Blocked by : Nicotine large dose – hexamethonium – tetraethyl ammonium parasympathetic nervous system: muscarinic receptors : Site : the effector organ Stimulated by : Muscarine – pilocarpine – anti-choline esterase Blocked by : Atropine – homatropine Types : M 1 , M 2, M 3 , M 4 and M 5 ( in CNS )