Lecture 19: Urinary System Flashcards
Inferior pole of kidneys are located where?
1 finger width above iliac crest
Between what levels are the kidneys located?
T12-L3
Superior pole of kidneys is located where?
Deep to ribs 11 and 12
Why is the right kidney lower than the left?
Because of the liver
Renal fascia
continuous superiorly with fascia lining on the inferior surface of diaphragm.
Renal mobility
During forced respiration : moves up 4cm
During quiet respiration : moves up 1 cm
Pathway of ureter
Ureter passes anterior to psoas major muscle and external iliac
blood vessels.
Left ovarian/testicular vein drains back to?
left renal vein
Other retroperitoneal structures drain back to IVC.
Renal vein, artery and pelvis positioning
Renal vein anteriorto renal artery which is anterior to renal pelvis at the hilum.
Blood supply to bladder
superior and inferior VESICLE arteries which branch from the internal iliac arteries.
At what vertebral level do the renal arteries branch?
branch from abdominal aorta at vertebral level L1 posterior to pancreas.
Transpyloric line, which pancreas traverses, is also at vertebral level L1.
Arcuate arteries
Arcuate arteries demarcate junction between cortex and medulla of kidney.
Renal Innervation parasympathetic and sympathetic
Renal plexus travels along renal artery.
Parasympathetic: vagus nerve to kidneys
• pelvic splanchnic nerves (S2-S4; not part of sympathetic trunk!!!) to distal ureters
• Sympathetic: Lesser and least thoracic splanchnic nerves to kidneys, proximal ureters
What are the locations in the renal system where renal stones are likely to occur?
Usually at points of relative constriction:
(1) junction of ureters and renal pelvis;
(2) where they cross external iliac artery & pelvic brim;
(3) where they pass through bladder wall.
Renal stones (calculi)
Pain can radiate from “loin to groin”
Pain distribution reflects pathway of visceral afferents (triggered by distended ureter) that course to spinal cord levels
T11-L1 via the sympathetic splanchnic nerves.
Female peritoneal reflections
Reflects from bladder to body of uterus forming VESICO-UTERINE POUCH
Reflects from vagina onto rectum forming RECTO-UTERINE POUCH
Pelvic pain line
Uterine tubes, ovaries & body of uterus superior to pelvic pain line. Cervix & vagina inferior to pelvic pain line.
Superior to line: visceral afferent fibres follow sympathetic fibres back to T12-L2 spinal cord.
Inferior to line: visceral afferent fibres follow parasympathetic fibres back to S2-S4 spinal cord.
Referred pain to the dermatomes => where do you feel ovulation pain? Where do you feel pain after a pap smear? Ectopic pregnancy pain?
Male peritoneal reflections
Reflects from bladder and seminal vesicles onto rectum forming
RECTO-VESICLE POUCH
Urination 3 things need to occur?
- Detrusor muscle (smooth) to contract
- Internal urethral sphincter (smooth) to open
- External urethral sphincter (skeletal) to open
To pee!
“Yes please, I’m busting!” = parasympathetic
stimulation, sympathetic inhibition = detrusor m.
contracts, internal sphincter relaxes and opens
(in males only!), voluntarily relax levator ani m.
to open external sphincter.
Not to pee!
“No thanks, I’m too busy!” = reduce
parasympathetic stimulation, increase
sympathetic stimulation, increase nerve activity
to levator ani m. (via pudendal nerve S2-S4) to
keep it contracted…more urine accumulates
Innervation of the bladder
- Inferior hypogastric plexuses.
- Sympathetic fibres from IML at L1/L2 sacral splanchnic
- Parasympathetic fibres from S2-S4 via pelvic splanchnic nerves.
- Afferent sensory fibres travel back along the pelvic splanchnic nerves.
Male urinary bladder, anterior view
Internal urethral sphincter
= smooth muscle (detrusor m.)
External urethral sphincter = skeletal muscle (levator ani m.)
Trigome
Trigone = smooth triangular portion of bladder wall formed by
the two ureter openings and the urethra. Mesodermal origin.
Detrusor muscle
Muscle fibres form the involuntary internal urtheral sphnicter which contracts during ejaculations to prevent semen entering bladder.
Diaphragm protects posterior aspect of superior
poles of kidneys from what?
Ribs
Kidneys are deep to the posterior abdominal wall
muscles in what region?
hypochondrium regions.
What effect will respiration have on the kidneys?
Elevates them
Function anatomy of kidney
Tubules extend in medulla.
• Tubules drain to collecting ducts.
• Collecting ducts form renal pyramids that drain filtrate (urine) into minor calyces.
• Minor => major calyces => renal pelvis => ureter.
A healthy bladder can store?
500ml
Male: The internal urethral sphincter is made of what muscle?
smooth muscle: detrusor muscle
Involuntary, controlled by ANS
Male: The external urethral sphincter is made of what muscle?
skeletal muscle: levator ani muscle
Voluntary, controlled by somatic nerves
Location of seminal vesicles
Seminal vesicles on posterior surface of bladder.
Urethra passes through prostrate.
What happens to urinary flow when the prostate is enlarged?
Restricts urine flow
The female has only one sphincter what is this?
External urethra sphincter
Female: what muscle is the external urethral sphincter made up of?
skeletal muscle: levator ani muscle
Voluntary
Controlled by somatic nerves
Implications for adult disease: reduced nephron number =>
High blood pressure
