Micturition Flashcards
uretal peristalsis is performed by ______ muscle in the ureters
Contractions are ______ by parasympathetic stimulation and ______ by sympathetic stimulation
smooth msucle
enhanced
inhibited
blockade of urine flow will result in an ______ in hydrostatic pressure in the ureter and subsequent ureter ______
increase in hydrostatic pressure
subsequent ureter dilation
a continued blockade of uretal outflow will lead to a _________ hydrostatic pressure in the kidney
and eventually hydronephrosis
increased hydrostatic pressure in the kidney
describe the ureterorenal reflex
blocked ureter –> pain –> sympathetic reflex tells kidneys to constrict renal arterioles –> decreased urine output
sites of UPJ obstruction
Ureterpelvic junction
behind testicular/ovarian av
over external iliac av (pevlic brim)
ureter transverses bladder wall (intramural part)
if the distance the ureter courses through the bladder is too short, contraction of the bladder will not completely occlude the ureter causing
urine to go back into the ureter during micturition, increases risk of pyelonephritis
dilates ureters
vesicoureteral reflex
during micturition, the detrusor muscle ______
contracts
Internal sphincter is _____
and located within the _____
involuntary
bladder neck
external sphincter is______ and located within the _____
voluntary
urogenital diaphragm
bladder afferent innervation
intravesicle pressure tretch signals (S2-S4) - sacral micturition center
bladder fullness is sensed by
alpha-delta fibers
bladder pain is sensed by
C fibers (unmyelinated)
pelvic nerve innervation of the bladder is __________ and its associated receptor is ____
parasympathetic
ACh signals M3 receptor (stimulates detrusor muscle)
hypogastric innervation of the bladder is ________ and interacts with two receptors: _____ in the bladder wall and _____ in the urethra to do what
sympathetic
B3 receptor in the bladder
A1 receptor in the urethra to inhibit detrusor muscle and contract internal sphincter?
pudendal nerve innervation of the bladder is ________ and innervates the __________
somatic
external sphincter
voluntary control
parasympathetic activity predominates while the bladder is
emptying
sympathetic activity predominates when the bladder is
filling
nicotinic receptors in the bladder are located at the ends of
somatic neurons at the external sphincter
muscarinic receptors are associated with what activity in the bladder
parasympathetic
emptying
M3 receptor
ACh NT
Adrenergic receptors in the bladder are associated with
alpha 1 in urethra/bladder neck
B2-3 in the detrusor
urine retention/filling
regulation of bladder filling and voiding is an ___ / ____ circuit
on/off
storage reflexes for urine are organized in the
spinal cord
voiding reflexes are organized in the
brain
when the bladder is filling, it activates _______ pathways and results in detrusor muscle ______
sympathetic pathways
results in detrusor muscle relaxation
when the bladder is full, it activates ______ reflexes that transmit to spinal cord and then to brain. Stimulates ________ outflow + inhibits _______
Results in detrusor muscle _____ and urethral sphincter ______
activates parasympathetic reflexes - stimulates parasympathetics
inhibits sympathetics and somatic outflow
Results in detrusor muscle contraction and sphincter relaxations
brainstem center responsible for controlling and coordinating activity of the sacral micturition center by activating external sphincter relaxation and sacral parasympathetic outflow
pontine micturition center
“Barrington’s Nucleus”
brainstem control center that recieves afferent bladder signals and passes on to higher brain centers, is the primary excitatory input to the PMC
periaqueductal gray
higher brain centers can suppress what passing on its input to the PMC
the PAG
to prevent incontinence
