Vasculature, nervous supply, stretch reflex of the bladder Flashcards
where does the bladder primarily receives its vasculature from?
the internal iliac vessels
where is arterial supply to the bladder derived from?
by the superior vesical branch of the internal iliac artery
which artery supplements the internal iliac artery in males?
supplemented by the inferior vesical artery
which artery supplements the internal iliac artery in females?
by the vaginal arteries
In both sexes, which arteries also contribute small branches to the arterial supply of bladder?
the obturator and inferior gluteal arteries also contribute small branches
how is venous drainage of the bladder achieved by?
by the vesical venous plexus
what does the vesical venous plexus empty into?
internal iliac vein
what is the internal iliac vein also known as?
the hypogastric vein
what is neurological input of the bladder from?
the bladder receives input from both the autonomic (sympathetic and parasympathetic) and somatic arms of the nervous system
via what does the sympathetic nervous system communicates with the bladder?
via the hypogastric nerve
nerve roots of hypogastric nerve?
T12-L2
what does the hypogastric nerve cause?
relaxation of the detrusor muscle
what does relaxation of detrusor muscle promote?
urine retention
what does the parasympathetic nervous system communicate with the bladder via?
the pelvic nerve
nerve roots of pelvic nerve?
S2-S4
what does increased signal from the pelvic nerve cause?
causes contraction of the detrusor muscle
what does contraction of the detrusor muscle cause?
stimulates micturition
what does the somatic nervous supply give us (in terms of the bladder)?
gives us voluntary control over micturition
what does the somatic nervous supply innervate in the bladder? via what?
the external urethral sphincter, via the pudendal nerve
what are the nerve roots of the pudendal nerve?
S2-S4
what can somatic nervous supply via pudendal nerve cause the bladder?
It can cause it to constrict (storage phase) or relax (micturition)
In addition to the efferent nerves supplying the bladder, what else is present? function?
there are sensory (afferent) nerves that report to the brain
where are the sensory (afferent) nerves found? function?
found in the bladder wall and signal the need to urinate when the bladder becomes full
what type of reflex is the bladder stretch reflex?
a primitive spinal reflex
what happens during the bladder stretch reflex?
micturition is stimulated in response to stretch
what type of reflex is the bladder stretch reflex similar (an analogous) to? example?
It is analogous to a muscle spinal reflex, such as the patella reflex
what happens to the control of the bladder during toilet training in infants?
this spinal reflex is overridden by the higher centers of the brain, to give voluntary control over micturition
what happens to the bladder when it fills with urine?
the bladder walls stretch
what happens as the bladder walls start to stretch?
Sensory nerves detect stretch and transmit this information to the spinal cord
what happens as the information is transmitted to the spinal cord?
Interneurons within the spinal cord relay the signal to the parasympathetic efferents (the pelvic nerve)
what does the Interneurons within the spinal cord relay the signal to the parasympathetic efferents via?
the pelvic nerve
what does the pelvic nerve act to do?
to contract the detrusor muscle, and stimulate micturition
describe the reflex arc of the bladder
Bladder fills with urine, and the bladder walls stretch. Sensory nerves detect stretch and transmit this information to the spinal cord.
Interneurons within the spinal cord relay the signal to the parasympathetic efferents (the pelvic nerve).
The pelvic nerve acts to contract the detrusor muscle, and stimulate micturition
when is the bladder stretch reflex non-functional?
post childhood
when does the bladder stretch reflex need to be considered?
in spinal injuries and in neurodegenerative diseases
why does the bladder stretch reflex need to be considered during spinal injuries?
the descending inhibition cannot reach the bladder
why does the bladder stretch reflex need to be considered during neurodegenerative diseases?
the brain is unable to generate inhibition
