Autonomic Nervous System - 1 PDF

Autonomic nervous system (A.N.S.) Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm *The physiological anatomy of A.N.S.: - Part of nervous system (peripheral nervous system), it is a motor neurons control involuntary actions (glands, cardiac & smooth Ms.) - According to its preganglionic cell bd...

Autonomic nervous system (A.N.S.) Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm *The physiological anatomy of A.N.S.: - Part of nervous system (peripheral nervous system), it is a motor neurons control involuntary actions (glands, cardiac & smooth Ms.) - According to its preganglionic cell bd. Location: Sympathetic N.S. Parasympathetic N.S. Lateral horn cells of Craniosacral: III, thoracolumbar: VII,IX,X Cranial Thoracic, upper & 2,3,4 Sacral 3 lumbar segments. segments. Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm *Autonomic ganglia funct. & types: -It acts as a distributing center as one preganglionic neuron synapses with 8-9 postganglionic neurons. Dr. Eman Ahmed Negm  1- Lateral 2-Terminal ganglia 3-Collateral (paravertebral) (prevertebral) ganglia ganglia One pair for each Inside the organ. Present at origin of spinal segment on big vessels (arise both side except from abdominal cervical has 3 pairs aorta), e.g.: celiac, ganglia (superior, superior and inferior middle& inferior mesenteric ganglia. cervical ganglia). For relay of For relay of For relay of both sympathetic nervous parasympathetic sympathetic & system only, called nervous system only, parasympathetic “sympathetic chain”. called nervous systems. “parasympathetic chain”. Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm *Function of sympathetic N.S.: Limb (skin & M.) Cardiopulmonary division (to thoracic viscera) Head & neck Abdominal & pelvic viscera Heart Eye Lung Abdominal Salivary Skin viscera glands Dr. Eman Ahmed Negm Pelvic viscera *Function of parasympathetic N.S.: Oculomotor (III) N. (Eye) Glosso-pharyngeal (IX) N. (Parotid gl. & Facial (VII) N. posterior 1/3 of (submandibular, sublingual Vagus (X) N. tongue) & lacrimal glangds.) 3 sacral, Pelvic N. (Rectum, U.B. & genitalia) Heart Gastrointestinal tract Lung (GIT) Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm  Parasympathetic Sympathetic Eye Pupil constriction Pupil dilatation (narrowing) due to “exophthalmoses”, ciliary & papillae ms VV. contraction. Salivary Vasodilatation & Vice versa (VV). (submandibular, increase secretion. sublingual, parotid), lacrimal & nasal glands Heart Decrease Coronary bl. VV. vessels.& Heart rate. Lung Bronchoconstriction VV. Dr. Eman Ahmed Negm  Parasympathetic Sympathetic Urinary bladder -Incr. micturition, - Retention of urine (increase wall contraction (inhibit wall & excitation & inhibit internal urethra of sphincter). sphincter) Rectum -Incr. defecation (increase - Faeces retention. wall contraction & inhibit anal sphincter). Male genitalia -Penis erection (Bl. Vs. - Penis shrinkage vasodilatation). (vasocontraction) -Incr. secretion of seminal -semen ejaculation. vesicle & prostate. Female genitalia - Clitoris erection -Clitoris shrinkage (vasodilatation) (vasocontraction) - Uterus relaxation. Dr. Eman Ahmed Negm  Parasympathetic Sympathetic GIT -Increase motility, -Decrease Motility except in sphincter relaxation spleen (helping it emptying (evacuate gall bladder RBCs into circulation). from bile juice). -Decrease secretion except -Increase secretion adrenal medulla (adrenaline, (Intestine, stomach, liver, noradrenaline), adrenal cortex pancreas). (cortisone). -Glycogenolysis (increase bl. Glucose). Skin -Vasoconstriction of cutaneous bl. vs. -Incr. sweating by sweat gl. -Hair erection (motor to erector pili M). Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm Fight or flight response: *(Defense behavior that prepare bd. in stress & emergency cases). *Called ”Sympathetic stress response”: sympathetic provide extra activation of bd., E, O2, glucose & F.A. needed for M. cont. through: 1)Respratory system: O2, remove Co2, depth & rate of breath, bronchodilatation For better ventilation. 2)Liver: glycogenolysis bl. Glucose. 3) Lipolysis: bl. free F.A. 4) Fibrinogen limits bleeding if wounded. Dr. Eman Ahmed Negm 5) C.V.S.: transport E to contracted M. & remove wastes by: Ht. rate & force of cont. Shift bl. From inactive organs (skin,..) (vasoconstricted) to active organs (cardiac & skeletal M.) (vasodilated bl. Vs.) 6) Spleen: contraction Hematocrit value& O2. (RBCs storage) 7) Sweating help bd. to get rid off waste products. 8) Adrenal gland: adrenal medulla (adrenaline, noradrenaline), adrenal cortex (cortisone) to still alert. Dr. Eman Ahmed Negm 9) Eye: field of vision by: Exophthalmia. Pupil dilatation (Relaxation of ciliary M). Eye lids retraction & wide of palpebral fissure (cont. of superior & inferior rectus Ms.) Dr. Eman Ahmed Negm  Rest or digest response: Parasympathetic action helps in digestion and absorption of food by increasing the activity of the intestinal musculature and increasing gastric secretion. Includes: 1-Dilating blood vessels leading to the GI tract, increasing the blood flow. 2-Constricting the bronchiolar diameter when the need for oxygen has diminished. 3-Constriction of the pupil and contraction of the ciliary muscles allowing for closer vision. 4-Stimulating salivary gland secretion, and accelerates peristalsis, mediating digestion of food and, indirectly, the absorption of nutrients secretion. Dr. Eman Ahmed Negm Dr. Eman Ahmed Negm