Urogenital 2

Question 1

in adults: strong afferent activity processed by? facilitates switch?

Answer 1

pontine micturition centre: facilitates switch from storage to micturition mode.

Question 2

in spinal cord injury: bladder becomes ___? meaning?

Answer 2

neurogenic: spinal reflexes work, but no more voluntary control = individual can’t sense a full bladder, can’t use output form micturition centre to switch from retention to micturition

Question 3

new innovation for SCI and bladder control?

Answer 3

surgery: patients can “scratch and pee”

Question 4

scratch + pee surgery: main idea?

Answer 4

stimulation of appropriate skin afferents evokes somatic reflex, and outflow of this reflex is channeled to bladder = promotes detrusor contraction + micturition

Question 5

scratch and pee surgery: how?

Answer 5

cut motor nerve is arranged to regenerate into nerves supplying bladder parasymp. ganglia

Question 6

scratch and pee surgery: cut what? joined to? then?

Answer 6

S1 motor nerve cut, joined to pelvic nerve. motor nerves regenerate and innervate bladder

Question 7

bladder control is a ___ reflex that is modulated ___? requirement for?

Answer 7

autonomic reflex, modulated centrally. requirement for ongoing activity in sympathetic + parasympathetic nerves

Question 8

urinary/micturition change vs. sexual response change?

Answer 8

urinary: change from sympathetic to parasympathetic. sexual: change from parasymp to sympathetic.

Question 9

female + male physiological responses are similar + involved 3 things?

Answer 9

erectile tissue engorgement (penis/clitoris corpora cavernosa fill with blood). glandular secretion. contraction of smooth + striated muscles

Question 10

what is involved in autonomic sexual response (4)

Answer 10

sexual arousal. central + peripheral inputs. involvement of hypothalamus + limbic areas. spinal reflexes.

Question 11

3 important types of nerves for sexual response

Answer 11

thoracocolumbar parasympathetic nerves. sacral parasympathetic nerves. pudental somatic nerves (efferent + sensory)

Question 12

sexual reflex: what cells? where?

Answer 12

reflex via LSt cells, in L3 + L4 of spinal cord

Question 13

penile erection/clitoral engorgement involves?

Answer 13

loss of a1 adrenergic tone to blood vessels supplying gentitalia (normal vasoconstriction, so now relaxation = more blood flow).

Question 14

increased filling of corpora cavernosa: increased what outflow? 3 effects?

Answer 14

increased parasympathetic cholinergic outflow = inhibits casoconstrictor activity of NA nerves. increases activity of NANC/NANCI nerves vasorelaxation via ATP/VIP. promotes NO release from endothelium.

Question 15

erection + venous drainage?

Answer 15

engorgement of corpora cavernosa passively blocks venous drainage

Question 16

ejaculation: how?

Answer 16

sympathetically mediated contraction of epididymis, vas deferens, seminal vesicles, prostate gland

Question 17

how does NO work?

Answer 17

activation of soluble guanylyl cyclase to produce cGMP

Question 18

sildenafil/viagra works by?

Answer 18

selective inhibitor of cGMP phosphodiesterase, aka prevents breakdown of cGMP

Question 19

yohimbine: what? does what? how?

Answer 19

a-adrenergic blocker: also produces erection. termination of erection might be due to stimulation of presynaptic alpha 2 recetpors on parasymp. terminals so blockade = erection