W12 Urine transport Flashcards
what are the three main components of the urinary tract
ureters
urinary bladder
urethra
what is the role of the micturition reflex
coordinates the process of urination
describe the 4 main stages in the micturition reflex
sensory fibers in the pelvic nerve sense stretch due to bladder filling
parasympathetic fibers control muscle contraction
interneurons communicate signals up to hypothalamus with relays into the cortex
voluntary relaxation of external sphincter results in urination
what do stretch receptors do as the urinary bladder fills
stimulate pelvic nerve
where does the stimulus from the pelvic nerve travel too
stimulates ganglionic neurons in wall of bladder
what does the postganglionic neuron in intramural ganglion do
stimulates detrusor muscle contraction
what relays sensation to thalamus and deliver sensation to cerebra cortex
interneuron
what results from the relaxation
relaxation of internal urethral sphincter
what two age ranges affect the micturition reflex
babys as they do not have the connections between the bladder and the hypothalamus are not mature
elderly reflex becomes impaired leading to incontinence.
what can loss of control micturition reflex be caused by
a stroke
alzheimer’s disease
CNS problems affecting cerebral cortex or hypothalamus
enlarged prostate
what is incontinence
involuntary loss of urine that is enough to cause a social or hygiene concern
what is chance of incontinence in female vs male
x4 in woman
what can stress incontinence be caused by
coughing
sneezing
laughing
carrying heavy weights
what is stress incontinence
anything that puts pressure on the bladder
when does stress incontinence occur
when the urethra moves out of the normal position (prolapses) after weakening of the pelvic floor muscles.
In woman what are some other causes of stress incontinence
childbirth
hysterectomy
menopause