Autonomic Nervous System PDF

AUTONOMIC NERVOUS SYSTEM Controls VISCERAL FUNCTIONS and GLANDULAR SECRETIONS ◦Atrial pressure animus aemx.am ◦Gastrointestinal motility...

AUTONOMIC NERVOUS SYSTEM Controls VISCERAL FUNCTIONS and GLANDULAR SECRETIONS ◦Atrial pressure animus aemx.am ◦Gastrointestinal motility É t ◦Gastrointestinal secretion anana ◦Urinary bladder emptying ◦Body temperature Parasympathetic System = rest and digest jY assume man sina.ie.am ◦Responsible for processes that CONSERVE and STORE ENERGY ◦Day-to-day control of basic visceral function ◦Breathing at rest, digestion, elimination of waste ◦Arises from CRANIAL NERVES and SACRAL SPINAL NERVES ◦Craniosacral system = PREGANGLIONIC NEURONS are located in the BRAINSTEM and SACRAL SPINAL CORD Sympathetic System = fight or flight ◦Target organs = sweat glands, piloerector muscles, blood vessels ◦Function when the animal is STRESSED ÉÉhiiii.fi ÉÉ ii ◦Enables vigorous physical activity with rapid production of energy I inoracolumbar ◦Increases heart rate, respiration, change blood flow to activate muscles and t F dilate pupils ◦Thoracolumbar system = SYMPATHETIC PREGANGLIONIC NEURONS y from INTERMEDIOLATERAL NUCLEUS of segments T1 - L3 Most viscera receive input from both —> basal rates are known as TONE 1j si is ◦The two systems work in ANTAGONIC FASHION to maintain HOMEOSTASIS ◦Balance of input from each system determines organ function Has AFFERENT, CENTRAL, and EFFERENT components ◦Target viscera are usually part of a reflex pathway that also include afferent pathways and CNS (hypothalamus) structures Hypothalamic control = acts as an INTEGRATOR ◦Made up of BRAINSTEM with some influence by CEREBRAL CORTEX ◦Afferent and efferent fibers of ANS travel via SPINAL CORD and CRANIAL NERVES to connect between CNS and TARGET ORGAN www.ss The ANS PREGANGLIONIC NEURON has its cell body in CNS and SYNAPSE with the POSTGANGLIONIC NEURON in the PERIPHERAL GANGLION I vi1 somanenoussisten ◦In parasympathetic the ganglion is usually located VERY CLOSE to TARGET newsmen ORGAN jÉÉÉ EE d autonominenouss on Preganglionic Neurons sympatheticsystem intermediolateral nucleus Are CHOLINERGIC in sympathetic and parasympathetic I ganglion nervous system Secretes ACETYLCHOLINE in synapse with postganglionic sympathetic i trunk i'i neuron Postganglionic Neurons i É Slow conducting unmyelinated axons (C fibers) isé stomach Innervated smooth muscle, cardiac muscle, glandular tissue Can EXCITE or INHIBIT target tissue g f proximalcolon Have VARICOSITIES distributed along length of branches Parasympathetic = Cholinergic = Acetylcholine kidney i Distal colon Sympathetic = Adrenergic = Norepinephrine nerves ◦Exceptions: Yager ‣ Synapse with glands = CHOLINERGIC uterus ‣ Synapse with renal vessels = DOPAMINERGIC Sympathetic Tone Under physical or emotional stress sympathetic system is capable of muscle muscle ciliary hi ma and MASSIVE COORDINATED OUTPUT with WIDESPREAD EFFECTS sun stands a a am Increase heart rate and blood pressure Bronchi I nucleus parasympathetic Pupil dilation cons Elevation of blood glucose and free fatty acids concentration m Increased arousal state i i Longer lasting effects i.iss esophagus i Adrenal Gland Adrenal Cortex pancreas ◦Mesoderm origin too memorization kidney ◦Steroid hormones good san sacramarasympatnetic roaringsugar ◦3 layers riddancesex urinary ‣ Zona Glomerulosa = mineralcorticiods = aldosterone ‣ Zona Fasciculata = glucocorticoids = cortisol reproductive externeanitaria ‣ Zona Reticularis = androgens = DHEA and androstenedione Adrenal Medulla ◦Ectodermal origin ◦Postganglionic neurons of SNS ◦Secretes catecholamines ‣ Epinephrine ‣ Norepinephrine Stress Response andgesturestorememberthe therearen main Parasympathetic Tone orthereceptorssendmeamessageandw functions i in Massive discharge of catecholamines sendavideo Generally concerned with the RESTORATIVE ASPECTS Increases bodies ability to perform of daily living VIGOROUS ACTIVITY LOWERS blood pressure by slowing down HEART ALPHA receptors = in arterioles of RATE and DECREASING the force of contraction - M2 visceral organs —> contraction of receptors arteriolar smooth muscle —> increase Enhances digestive activity blood pressure, restrict blood flow ◦Increases blood flow to GI tract ◦Increase rate of blood coagulation ◦Increases intestinal motility —> increase platelet aggregation ◦Stimulates secretion of digestive enzymes ◦ALPHA 1 = ◦Relaxes the pyloric sphincter ‣ increase breakdown of Autonomic Reflexes glycogen in liver and muscle Homeostatic reflexes ‣ Dilates pupils Control blood pressure ◦ALPHA 2 = inhibits insulin ◦Important in maintaining sufficient brain blood flow secretion and increases glucagon ◦Stretch receptors in the internal CAROTID release ARTERY and AORTA detect systemic blood BETA receptors pressure ◦BETA 1 = ◦Baroreceptor to measure blood pressure ‣ Increase heart rate and force ◦Afferent neuron carry information to the medulla of contraction of each oblongata heartbeat ◦Brainstem centers (medulla) process the ‣ increase renin release by information and coordinate an appropriate response kidneys —> increases blood ◦Efferent neurons direct changes in the heart and pressure blood vessels ◦BETA 2 = ‣ Vasodilation of skeletal muscle, liver arterioles and coronary blood vessels ‣ Relaxes smooth muscle from airways —> more O2 from lungs ‣ Increases gluconeogenesis ‣ Increases breakdown of glycogen in liver and muscle ◦BETA 3 = stimulate lypolysis in adipose tissue —> increase fatty acid availability