Autonomic Nervous System - Nursing PDF

Autonomic nervous system  The physiologic anatomy of autonomic nervous system (ANS) Sympathetic fibers arise from lateral horn cells of all thoracic and upper three lumbar segments (thoraco-lumbar in origin). Parasympathetic fibers arise from the nuclei of cranial nerves number...

Autonomic nervous system  The physiologic anatomy of autonomic nervous system (ANS) Sympathetic fibers arise from lateral horn cells of all thoracic and upper three lumbar segments (thoraco-lumbar in origin). Parasympathetic fibers arise from the nuclei of cranial nerves number III, VII, IX and X, and the sacral segments number 2,3 and 4 (cranio-sacral in origin). The origin of sympathetic nervous system is A. Cranial nerve B. Lumbar segments C. Sacral segments D. Cervical segments The characters of autonomic nervous system The portion of the nervous system that controls most visceral functions of the body is called the autonomic nervous system One of the most striking characteristics of the autonomic nervous system is the intensity with which it can change visceral functions. All the following are characters of ANS EXCEPT a. Controls most visceral functions of the body b. Involuntary part of the nervous system c. Very intense in changing visceral functions d. Control the somatic functions of the body One of the following is NOT supplied by autonomic nervous system a. Heart b. Lung c. Stomach d. Skeletal muscles Cartoons demonstrating fight or flight response  Fight or flight response These responses are associated with defense behaviors which prepare the body for the stress of threatening situations and emergency as muscular exercise. The purpose of sympathetic system is to provide extra activation of the body in state of stress; this is often called the sympathetic stress response.  Fight or flight response (con.) The sympathetic system provides energy (oxygen, glucose and fatty acids) for contracting muscles by the following response: 1. Respiratory system: ↑ oxygenation of blood, and remove CO2 through: Bronchodilatation allowing better ventilation. Increase depth and rate of respiration. 2. Liver: Glycogenolysis →↑ glucose level in blood. Lipolysis: Free fatty acids are increased in blood.  Fight or flight response (con.) 3. Cardiovascular system: Transports energy producing substances to contracting muscles and removes waste products. Heart: increased heart rate and force of contraction. Blood vessels: vasoconstriction leads to rise in blood pressure. Blood: is shifted from inactive organs whose blood vessels are constricted (skin and splanchnic area) to active organs (cardiac and skeletal muscles) whose blood vessels are dilated.  Fight or flight response (cont.) 4. Splenic contraction: leads to increased Hematocrit value. Thus, more oxygen is supplied to tissues. 5. Sweating: helps the body to get rid of the waste heat. 6. Increases the field of vision in the eye due to: Pupillodilatation due to contraction of pupillodilator muscle. Contraction of superior tarsal muscles leading to elevation of eye lids and widening of the palpebral fissure. Exophthalmos due to contraction of Muller´s muscle. The sympathetic response in a “fight or flight” reaction causes a decrease in a. Arterial blood pressure b. Diameter of the pupil c. Diameter of skin blood vessels d. Blood glucose concentration Sympathetic stimulation is responsible for a. Inhibition of glycogenolysis b. Inhibition of lipolysis c. Decrease in rate of respiration d. Bronchodilatation Fight or flight response includes all of the following EXCEPT a. Increased heart rate b. Increased ventricular contraction c. Decreased arterial blood pressure d. Shift the blood from inactive to active organs  Short essay question Explain increased field of vision by sympathetic stimulation? Pupillodilatation Widening of the palpebral fissure Exophthalmos Functions of sympathetic and parasympathetic 1. Parasympathetic NS: stimulatory for digestion, defection, urination, and erection Specialized in sleep and digestion Anabolic in action 2. Sympathetic NS: inhibitory for digestion, defection, urination and ejaculation Specialized in mental (e.g. fear and anxiety) and physical stress (exercise) Catabolic in action Has generalized actions affecting many organs Sympathetic stimulation is most pronounced during a. Sleep b. Feeding c. Fear d. Urination Functions of sympathetic nervous system 1. Head and neck ▪ The innervation arises from 1st and 2nd thoracic segments ▪ Increase cerebral blood flow and produce mental alertness ▪ Dilate the pupil of eye ▪ Adaptation to far vision ▪ Widening of palpebral fissure ▪ Erection of hairs ▪ Vasoconstrictor to the skin blood vessels ▪ Increased sweating Effects of sympathetic nervous system on head and neck include all the following EXCEPT a. Narrowing of palpebral fissure b. Erection of hairs c. Widening of palpebral fissure d. Vasoconstriction of cutaneous blood vessels Stimulation of the cervical sympathetic nerve causes a. Dropping of the upper eyelid b. A small-sized pupil c. Enophthalmos d. Adaptation to far vision  Functions of sympathetic nervous system (cont.) 2. Thoracic viscera The innervation arises from upper 5 thoracic segments Widening of air passage Stimulatory to all properties of heart. Vasodilator to coronary blood vessels. Effects of sympathetic nervous system on the thoracic viscera include all the following EXCEPT a. Increase in heart rate b. Constriction of air passage c. Widening of air passage d. Vasodilation of coronary blood vessels  Functions of sympathetic nervous system (cont.) 3. Abdominal viscera The innervation arises from lower six thoracic segments Greater splanchnic nerve Squeezing of the spleen Inhibition to plain muscles of the stomach and small intestine but motor to the sphincters. Glycogenolytic to the liver glycogen. Secretory to suprarenal medulla. Stimulation of greater splanchnic nerve produces a. Increased motility of the stomach & upper half of the small intestine b. Inhibition of micturition c. Increased blood levels of glucose d. Vasoconstriction in the erectile tissues of both males & females Stimulation of greater splanchnic nerve produces a. Increased blood glucose level b. Decreased blood volume c. Secretion of 20% adrenaline & 80% noradrenaline from adrenal medulla d. Increased gastrointestinal motility Sympathetic fibers to the abdominal viscera a. Originate from lateral horn cells of upper 6 thoracic segments b. Is responsible for ejaculation of semen c. Increase blood glucose level by decreasing liver glycogen d. Produce relaxation of muscles and sphincters of small intestine Functions of sympathetic nervous system (cont.) 4. Pelvic viscera (presacral nerve) The innervation arises from upper three lumbar segments Urine retention. Fecal retention. Ejaculation of semen. Shrinkage of genital organs. Sympathetic supply to the pelvic viscera cause a.Micturition b.Dilatation of vessels in external genetalia c.Defection d. Ejaculation Sympathetic fibers to pelvic viscera a. Produce ejaculation of semen and shrinkage of penis b. Originate from all lumbar and upper 3 sacral segments c. Produce vasodilation of pelvic blood vessels d. Inhibit defecation and mediate micturition Activation of sympathetic nervous system causes contraction of smooth muscle in which of the following? a. Bronchioles b. Pupils c. Intestine d. Arterioles Activation of sympathetic nervous system produces the following EXCEPT a. Bronchodilatation b. Tachycardia c. Mydriasis d. Contraction of urinary bladder wall Stimulation of sympathetic NS causes a. Adaptation for near vision b. Generalized actions affecting many organs c. Bronchoconstriction d. Decreased glycogenolysis & lipolysis Generalized sympathetic activity is characterized by the following EXCEPT a. Contraction of the radial muscles in the iris b.A raised blood levels of catecholamines c. Constriction of blood vessels in the skin d.A fall in blood glucose level Functions of parasympathetic nervous system 1- Oculomotor nerve (cranial nerve III) Constriction of pupil of the eye, contraction of ciliary muscle leading to increase in the power of lens which is important for adaptation to near vision 2- Facial nerve (cranial nerve VII) Secretory and vasodilator to blood vessels of submandibular and sublingual salivary glands Vasodilator to blood vessels of anterior 2/3 of the tongue Vasodilator to blood vessels and secretory to lacrimal glands 3- Glossopharyngeal nerve (cranial nerve IX) Vasodilator to blood vessels and secretory to parotid salivary gland Vasodilation to posterior 1/3 of tongue Facial nerve a. Stimulation increases the power of the lens of the eye b. Supplies the lacrimal gland c. Supplies the parotid salivary gland d. Contains sympathetic postganglionic fibers Salivary secretion increases on stimulation of a. Trigeminal nerve b. Glossopharyngeal nerve c. Vagus nerve d. Hypoglossal nerve The action of parasympathetic in the salivary glands a. Vasoconstriction and secretion b. Vasodilation and secretion c. Vasodilation and inhibition of secretion d. Vasoconstriction and inhibition of secretion Functions of parasympathetic nervous system 4- Vagus nerve (cranial nerve X) Is originated from vagal nucleus in medulla Bronchoconstriction Inhibitory to all properties of the heart It decreases heart rate and O2 consumption by the heart Motor to plain muscles of esophagus, stomach, small intestine, proximal ½ of large intestine Inhibitory to their sphincters Secretory to glands to stomach, pancreas and liver Evacuation of gall bladder Vagal stimulation causes a. Tachycardia b. Dilatation of the bronchi and bronchioles c. Relaxation of smooth muscles in stomach and small intestine d. Increase in gastric and pancreatic secretion Parasympathetic fibers to the thoracic and abdominal viscera a. Dilate bronchi and bronchioles b. Stimulate ventricular contraction c. Decrease the oxygen consumption of the heart d. Inhibit pancreatic secretion Stimulation of the Vagus nerve does NOT produce a. Increased heart rate b. Dilation of pulmonary blood vessels c. Increased pancreatic secretion d. Contraction of the wall of gall bladder  Functions of parasympathetic nervous system (con.) 5- Pelvic nerve (sacral outflow) Is originated from 2, 3 and 4 sacral segments Nerve of micturition (urination) Nerve of defecation Nerve of erection The nerve of micturition is a. Oculomotor b. Glossopharyngeal nerve c. Vagus nerve d. Pelvic nerve Stimulation of the pelvic parasympathetic nerves produces a. Relaxation of rectal wall and contraction of internal anal sphincter b. Vasoconstriction of blood vessels causing erection of penis c. Contraction of bladder wall and relaxation of internal urethral sphincter d. Ejaculation of semen Stimulation of pelvic nerve (sacral autonomic) produces a. Relaxation of rectal wall & contraction of internal anal sphincter b. Vasoconstriction of blood vessels in external genetalia causing erection of penis c. Contraction of urinary bladder wall & relaxation of internal urethral sphincter d. Contraction of smooth muscles in male sexual passages causing ejaculation Stimulation of pelvic nerve causes a. Contraction of the bronchial muscle b. Contraction of the internal urethral & anal sphincters c. Vasodilatation of blood vessels in the external genetalia d. Stoppage of prostatic secretion The following cranial nerve carries parasympathetic nerve fibers a. Cranial nerve number IV (4) b. Cranial nerve number III (3) c. Cranial nerve number XII (12) d. Cranial nerve number VIII (8)  Comparison between sympathetic Compare? and parasympathetic NS Parasympathetic stimulation produces all of the following EXCEPT a. Decreased heart rate b. Bronchodilation c. Increased gastric secretion d. Urination Motility of the intestine is increased by a.Adrenaline b.Parasympathetic stimulation c.Parasympathetic blockers d.Adrenal medulla secretions