ANS Damage Flashcards
symptoms of Horner’s syndrome
ptosis (drooping eye), miosis, enophthalmos (posterior displaced eye), anhidrosis ipsilateral, change eye color
What are locations Horner’s syndrome can occur?
paraventricular nucleus of hypothalamus, brainstem, the rostral ventrolateral nucleus or nucleus solitary of medulla, lateral horn of spinal cord at C1-C8; T1-L2 or intermediolateral nucleus of spinal cord, sympathetic trunk, superior cervical ganglia
What are autonomic nerves of parasympathetics
3, 7, 9, 10 and S2-S4 (which synapse at inferior hypogastric plexus)
What does pudendal nerve somatically control?
external sphincters and deep transverse perineal muscle
Somatic pathway of voiding
precentral gyrus > micturition center of pons > alpha motors of pudendal and external urethral sphincter
Allows bladder to fill (increase capacity) without increasing pressure
Contract internal urethral sphincter (keep urine in bladder)
hypogastric nerve T10-L2
What is path of spinal reflex of urination loop?
Stretch receptors in smooth muscle of bladder send information to spinal cord via dorsal root ganglia cells
Cells from the dorsal root ganglion innervate preganglionic parasympathetic neurons at S2-S4.
Postganglionic neurons innervate the bladder “detrusor muscle” and make it contract (babies don’t have the somatic control, but they have this pathway that’s why they just pee themselves)
How does one get a neurogenic bladder?
bilateral lesions at S2-S4. If it’s UMN (above S2-S4) you don’t get the neurogenic bladder but incontinence because you can’t tell brain to hold pee. If LMN you need a cath
Motor:
External anal sphincter
Levator ani
pudendal
what do symp and parasymp contract in defecation
symp relaxes internal sphincter and parasymp contracts bowel SM. If you damage UMN you get incontinence and LMN you can’t defecate
what happens in defecation if you have weak pelvic floor
incontinence
Contract erectile muscles
Initiate prostatic expulsion
somatic
reflexogenic erection
genital stimulation causes afferent signal via pudendal n. to SEC (spinal erection center) and returns efferent signal via inferior hypogastric plexus. Mostly independent of cortical influence. (so all good if you injure above S2-S4)
psychogenic erection
cortical processing of sensory stimuli. The cortical centers influence SEC (spinal erection center) which cause erection via activation via inferior hypogastric plexus.
symptoms of cauda equina, spina bifida
No reflex for bowel and bladder,
Sexual dysfunction,
Saddle anesthesia,
Lower extremity paralysis
