Anatomy Flashcards
what does the urinary tract consist of?
kidneys
ureters
bladder
urethra
are the kidneys retroperitoneal?
yes
what does retroperitoneal mean?
behind the peritoneum
what are the kidneys enclosed within?
renal capsule perinephric fat deep fascia paranephric fat visceral peritoneum
why does the right kidney lie inferior to the left?
size of the liver
what vertebral level does the right kidney sit at?
L1-3
hilum at L1/2
what vertebral level does the left kidney sit at?
T12-L2
hilum at L1
which ribs protect the kidney?
floating ribs 11 and 12
what do the floating ribs risk being so close to the kidneys?
lacerations
what does the renal hilum consist of?
renal pelvis (posterior) renal artery (middle) renal vein (anterior) lymphatics nerves renal sinus fat
why is the left renal vein longer than the right?
passes the aorta anteriorly to join right-sided IVC
why do the kidneys move inferior on inspiration?
liver and spleen touch the diaphragm superiorly and superior poles of the kidneys inferior
where does lymph from the kidney’s drain to?
lumbar nodes
where does lymph from the ureters drain to?
lumbar and iliac nodes
two types of RAS associated with AAA
- combined with infra-renal AAA
2. supra-renal AAA
two layers of the kidney
outer cortex
inner medulla
urine drainage pathway from the kidney
nephron collecting duct minor calyx major calyx renal pelvis ureter
two types of ureteric obstruction
- internal
2. external
examples of internal ureteric obstructions
impacted calculus
blood clot
examples of external ureteric obstructions
expanding mass
sites of constriction in the ureters
- pelvic-ureteric junction
- ureter crosses common iliac artery bifurcation
- ureteric orifice
what is in the walls of the ureters?
smooth muscle
what produces colicky pain with an obstruction in the ureters?
there is increased peristalsis by the smooth muscle in the walls of the ureter proximal to the obstruction in an attempt to remove it
what is hydronephrosis?
swelling of the kidney due to urine backing up which can compress nephrons and lead to kidney failure with painful stretching of the renal capsule
what direction do the ureters enter the posterior bladder wall?
inferomedially
why do the ureters enter the posterior bladder wall inferomedially?
prevent reflux of urine when bladder contracts
detrusor muscle also encircles the orifices and prevents reflux
what forms the trigone?
two ureteric orifices
internal urethral orifice
what is the trigone?
triangle shape on internal aspect of the bladder
what is the muscle of the bladder wall called?
detrusor muscle
what does the detrusor muscle form around the urethra?
forms the internal urethral orifice which contracts during ejaculation
describe embryological development of the testes?
move from posterior abdomen through inguinal canal to the scrotum
what does the spermatic cord consist of?
testicular artery testicular vein vas deferens lymphatic vessels nerves
what do the testes sit within?
tunica vaginalis
what is a hydrocele?
excess fluid in the tunica vaginalis
three motor functions of the renal system
- ureteric peristalsis
- bladder contraction
- urethral sphincter control
what produces ureteric peristalsis?
autonomic action initiated by ureteric cells which have auto-rhythmicity
what produces bladder contraction?
parasympathetics stimulates detrusor muscle to contract
what are the five types of nerve fibre?
- somatic sensory
- visceral afferents
- somatic motor
- sympathetic
- parasympathetic
role of somatic sensory nerve fibres?
sensations from body wall (soma)
role of visceral afferent nerve fibres?
sensations from organs
role of somatic motor nerve fibres
motor response to body wall (muscles)
role of sympathetic and parasympathetic fibres
responses to organs
how do sympathetic fibres reach the kidneys, ureters and bladder?
leave the spinal cord at T10-12 and enter sympathetic chains bilaterally
leave within abdominopelvic splanchnic nerves synapsing with abdominal sympathetic ganglia at abdominal aorta
reach organ via periarterial plexus
how do parasympathetics innervate the kidney and ureter?
vagus nerve
what parasympathetic innervates the bladder?
pelvic splanchnic nerves
describe the mechanism behind urinary continence
- bladder filling is sensed by stretch receptors of visceral afferents
- enter CNS via S2-4
- reflex is to empty bladder by stimulation of detrusor and inhibition of internal sphincter
- brain overrides and APs in inhibitory nerves arrive
- voluntary contraction of external sphincter and levator ani
nerves that arise from the sacral plexus
pudendal (S2,3,4) sciatic (L4-S3) femoral (L2-4) obturator (L2-4) iliohypogastric ilioinguinal lateral cutaneous nerve of the thigh genitofemoral
