Kidneys and Urinary System Flashcards
What organs are in the urinary system?
Kidneys adrenal glands ureters urinary bladder urethra
Where is the renal angle?
Junction of the 12th rib and lateral border of erector spinae
When would the kidneys be palpable?
If enlarged or very low body fat
Where do the kidneys sit?
In the paravertebral gutters
On the posterior abdominal wall
Extend below inferior ribs
What are the right anterior relations of the kidneys?
Liver - pushes right kidney down
Duodenum/small intestine - above right kidney
Right hepatic flexure
What are the left anterior relations of the kidneys?
Spleen Stomach Pancreas Left hepatic flexure Small intestine
What is another name for the hepatorenal recess?
Morrison’s pouch
What is the hepatorenal recess?
separates the liver from the right kidney
fluid can collect here in pathologies
What are the posterior relations of the kidneys?
Diaphragm Psoas major Quadratus lumborum Transversus abdominis T12 - subcostal nerve L1 - iliohypogastric and iligoinguinal nerve
Where are the renal arteries?
- Arise at L1/L2
- right renal artery passes posterior to IVC
Where are the renal veins?
- Arise at L2 vertebral level
- anterior to aorta
What are the differences between the left and right renal veins?
- left renal vein is longer than right due to right’s lateral position near iVC
- left is longer and receives suprarenal and gonadal veins whilst right drains to IVC
How much CO does the renal artery supply to the kidneys?
1/4 - 1200ml/min
What does the renal artery divide the hilum into?
4/5 segmental arteries supplying discrete renal segments
What is the nerve supply to the kidneys?
- renal plexus MOTOR - sympathetic (thoracic and lumbar splanchnic nerves) and PS (vagus) SENSORY - afferent fibres enter T10-T12
What are the ureters?
Retroperitoneal
SM tubes
Pass over pelvic brim at common iliac artery bifurcation
Run on lateral pelvis walls
Opposite ischial spine, curve anteromedially
Oblique entrance into bladder via one flap valve
Propel urine to bladder via response to SM stretch
What is the wall of ureters like?
Tri-layered wall:
- transitional epithelial mucosa
- SM muscularis
- fibrous CT adventitia
What is the nerve supply to the ureters?
- visceral afferents enter at spinal levels T11-L1/2
- loin pain referred along ilioinguinal and iliohypogastric nerves (L1)
- pain can change and be referred to genitofemoral nerve if kidney stone descends (L1,2) so pain over groin and scrotum/labia majora
Where is the urinary bladder?
Retroperitoneally lies on pelvic floor posterior to pubic symphysis
- connected anteriorly to umbilicus via median umbilical ligament (urachus)
What is the wall of the bladder like?
- transitional epithelial mucosa
- thick muscular layer
- fibrous adventitia
What is the trigone?
Triangular area between ureters and urethra
Clinically important for infection
What is the urethra?
Muscular tube that drains urine from bladder conveying it out of the body
Has sphincters keeping urethra closed when urine is not being passed
What are the urethral sphincters?
- internal (males have anatomical, woman is physiological): involuntary at bladder-urethra junction preventing retrograde ejaculation
- external voluntary sphincter surrounding urethra passing through urogenital diaphragm
- levator ani muscle: voluntary
What is the female urethra like? Where is it?
Tightly bound to anterior vaginal wall
External opening lies anterior to vaginal opening and posterior to clitoris
What is the male urethra like?
double curvature
divided into 4 sections as it passes through pelvic structures
What are the 4 structures of the male urethra?
- intramural (pre-prostatic): length varies on bladder filling
- prostatic: contains ejaculatory ducts
- intermediate (membranous): penetrates perineal membrane, surrounded by external urethral sphincter
- spongy: final part in corpus spongiosum of penis
What is micturition?
Urination
Emptying bladder
How is micturition controlled?
- Distension of bladder walls initiates sympathetic reflexes (visceral afferents)
- symp (hypogastric nerve) stimulates contraction to close internal urethral sphincter inhibiting detrusor muscle preventing contraction and bladder emptying
- PS: stimulates detrusor muscle to contract, inhibits and opens internal urethral sphincters
- somatic: external urethral sphincter via pudendal
What muscles are posterior to the kidney?
- transversus abdominis
- quadratus lumborum
What nerves are posterior to the kidney?
T12 - subcostal nerve
L1 - iliohypogastric and ilioinguinal nerves
What surrounds the kidneys?
Fat and fascia
Muscles of the back
What are the layers of fat and fascia surrounding the kidneys?
(outer) pararenal fat renal fascia/Gerota's fascia perirenal fat renal capsule (inner)
What are the parts of the kidney?
Inner medullary pyramids Outer cortical region (cortex) Minor calyx Major calyx Pelvis ureter
What is the drainage of the urine?
Collecting ducts -> renal papilla -> minor calyx -> major calyx -> renal pelvis -> ureter
What is the blood supply to the kidneys?
Renal artery -> 5 segmental arteries -> interlobar arteries -> arcuate -> interlobar arteries -> afferent arterioles -> glomerular capillaries
What is the venous drainage of the kidneys?
Capillaries -> interlobular veins -> arcuate veins -> interlobar veins -> renal veins
What is the lymph drainage of the kidneys?
To the lateral aortic lymph nodes
Where is pain felt from the kidneys?
- direct = kidney region
- referred = groin
What is the blood supply to the ureters?
From renal arteries, testicular arteries and common iliac arteries
What is the voiding reflex?
PS action to permit pee
Opposite to bladder distension where symp stops pee
