Exam 3 Week 13 ppt 3 ANS innervation Flashcards
Heart sympathetic- causes
stimulation increases rate & force of contraction
Heart sympathetic- efferent fibers from
the upper thoracic segments (T1-T6) Via cervical & upper thoracic ganglia
Heart sympathetic- innervates
~Innervation of sinoatrial (SA) & atrioventricular (AV) nodes
~atrial & ventricular cardiac muscle
Heart sympathetic- produces
~produce Positive chronotropic & dromotropic effects
~increases heart rate (chronotropic effect) and rate of conduction through the atria & specialized conduction system of the ventricles (dromotropic)
~produces Positive ionotropic effect both atria and ventricles (increased force of contraction)
Heart parasympathetic- causes
decreases in HR
Heart parasympathetic- efferent fibers from
Fibers of Vagus nerve (CN X)
Heart parasympathetic- innervates
~SA and AV node
~atrial muscle
Heart parasympathetic- produces
~decrease in heart rate and speed of conduction through the AV node (Negative chronotropic & dromotropic effects)
~only a variable negative ionotropic effect on atria only
Heart baroreceptors located
High pressure baroreceptors in carotid sinus & aorta
Heart baroreceptors- afferents from
brainstem via CN IX (glossopharyngeal) & CN X (vagus) from the baroreceptors in carotid sinus & aorta respectively
Heart baroreceptors- relay in
solitary nucleus
Heart baroreceptors- inhibits
~inhibit cardiac acceleratory center & excite cardiac inhibitory center
~Inhibit sympathetic & stimulate parasympathetic
vasculature sympathetic- produces
~vasoconstriction which will increase blood pressure
~
vasculature sympathetic- how do baroreceptors influence?
~Baroreceptor reflex afferents decreases sympathetic outflow so produces vasodilation
~causes Vasodilation & decreased heart rate & contractility decreases blood pressure
bladder sympathetic- located
spinal cord segments T11-L2 Via inferior mesenteric & pelvic ganglia
bladder sympathetic- produces
~relaxation of the detrusor
~contraction of the internal urethral sphincter
~preventing the bladder from emptying
bladder parasympathetic- location
Originates from spinal intermediate gray of S2-S4
bladder parasympathetic- produces
~contraction of the detrusor
~emptying of the bladder
bladder external urinary sphincter- originates
Originates from S2-S3 (Onuf’s nucleus – S2)
bladder external urinary sphincter- travels to bladder by
travels to the pelvic floor by the pudendal nerve
bladder external urinary sphincter- what does it do
voluntarily prevent micturation until convenient to urinate
what type of fibers send signals from the bladder?
A-delta fibers
what to the fibers from the bladder do (and the path they travel)
~myelinated afferents (A-delta fibers) from the bladder- connected to the tension receptors in the bladder wall
~Relayed by neurons in dorsal horn of spinal cord to ascend in the dorsolateral funciculus, Relay in thalamus to end in insular cortex gives sensation of bladder “fullness”
what is micturition controlled by?
pontine micturition center
what does the pontine micturition center do?
~Stimulates parasympathetic producing detrusor contraction
~Inhibits sympathetic relaxing internal urinary sphincter
~Inhibits motor neurons relaxing external urinary sphincter
~allows Bladder to empty
what excites pontine micturition center?
Excited by periaqueductal gray which was activated by afferents from bladder
pontine storage center- excites
Excites Onuf’s nucleus
pontine storage center- produces
closure of external urinary sphincter so decreased urination
what are the cortical areas that are active during micturition
~Prefrontal cortex
~Anterior cingulate gyrus
~Supplemental motor area
~Insula
sex organs sympathetic- innervation from
spinal cord segments T10-L2
sex organs sympathetic- results in
~Vaginal contraction
~Penile ejaculation
~contraction of the internal urinary sphincter prevents retrograde emission of semen into bladder.
sex organs parasympathetic- innervation from
spinal cord segments S2-S4
sex organs parasympathetic- results in
secretion of vaginal glands, engorgement of the clitoris, and penile erection
sex organs parasympathetic- disruption
Erectile dysfunction