Anatomy and embryology of Urinary system Flashcards
What are the components of the urinary system? And what are their individual functions?
- Kidneys - maintain homeostasis by blood filtration.
- Ureter - carries urine from kidney to urinary bladder.
- Urinary bladder - stores urine, allowing urination to be controlled.
- Urethra - carries urine from bladder to outside body.
Why is the urinary system important? (5 points)
- Removes metabolic waste from blood by filtration and excretion.
- Regulates plasma electrolytes and blood pressure.
- Help to stabilise the pH
- Reabsorption of small molecules.
- Produces erythropoietin
(stimulant of RBC production by bone marrow).
At what level do the kidneys lie?
Retroperitoneal at level of T12-L3.
What vertebral level is the transpyloric plane and what lies at this level?
L1 - Hilus of kidney lies at this level.
Each kidney is enclosed by 4 layers, what are they?
- Fibrous renal capsule
- Fatty renal capsule
- Renal fascia - libro fatty tissue
- Pararenal fatty tissue - mainly on posterior aspects of kidney.
What are the posterior relations of the kidney?
Diaphragm
Psoas major
Quadratus lumborum
12th rib
What are the structures that make contact with the anterior surface of the right kidney?
Suprarenal gland Liver Duodenum Colon Jejunum
What are the structures that make contact with the anterior surface of the left kidney?
Suprarenal gland Stomach Spleen Pancreas Small intestine Left colonic flexure
At what vertebral level are the paired renal arteries given off from abdominal aorta?
L1/L2
What are the arteries and veins supplying the kidneys?
VAP
Right Renal artery (segmental branches x5)
Right Renal vein
Left renal artery (segmental branches x5)
Left renal vein
Where do the renal veins drain into?
Inferior Vena Cava
Where does the left renal vein travel?
Anterior to aorta, relatively long.
Where does the right renal vein travel?
Directly, relatively short.
Where does the left renal artery travel?
Directly, relatively short.
Where does the right renal artery travel?
Posterior to IVC, relatively long.
What is the lymphatic drainage of the kidneys?
Lateral aortic / para-aortic lymph nodes.
What is the nerve supply of the kidneys?
Renal plexus: sympathetic T10-L1, sensory afferent = T11-12
What are the arteries of the urinary bladder?
Branches of the internal iliac artery
What are the veins of the urinary bladder?
Drains into the internal iliac veins
What are the lymphatics of the urinary bladder?
External iliac lymph nodes: Suprapubic part.
Internal iliac lymph nodes: Infrapubic part.
Nerve supply of the urinary bladder?
Sympathetic: T11-L2
Para: S2-4
Somatic: pudendal nerve (voluntary control)
What are the constrictions of the ureter?
First constriction = ureter passes over inferior renal pole (abdominal part)
Second constriction = ureter crosses over external iliac vessels
Third constriction: ureter traverses the bladder wall (intramural part)
* stones may lodge here.
What is contain in the internal structure of the kidney?
Cortex and medulla.
Medulla: Pyramid - Papilla - minor calyx - major calyx - pelvis - ureter.
Renal lobe.
What is the functional unit of the kidney?
The Nephron - purified blood going back via renal veins.
- What is a nephron?
- What is the renal corpuscles?
- What is uriniferous tubule?
- Nephron = renal corpuscles + renal tubules
- Renal corpuscles = Glomerulus + bowmen’s capsule
- Uriniferous tubule = nephron + collecting duct
What is the function of the proximal convoluted tubule?
Reabsorption.
What is the difference in the histology of the cortex and the medulla?
Cortex = Glomerulus Medulla = all the tubes.
What is significant about the histology of the ureter?
Star shaped lumen.
What are the most common developmental anomalies in urinary system?
Aberrant renal arteries Pelvic kidney Unilateral double kidney Horseshoe kidney Double ureter Congenital polysistic kidney disease Pancake kidney
What does the intermediate mesoderm form?
Urinary and reproductive systems
What is the allantois?
Out pouching of endoderm at the hindgut that extends into the body stalk.
Body stalk later forms umbilical cord.
- What is the cloaca?
2. What is it divided into?
- Single posterior opening - used to expel faces.
- Rectum posteriorly
Urogenital sinus anteriorly
What does the urogenital sinus form?
Urinary bladder and caudal end forms urethra
What forms the definitive kidney?
A ureteric bud that develops off the mesonephric duct.
And metanephric mesoderm.
Reciprocally induce each other.
What happens to the ureteric bud?
Undergoes repeated branching - stalk becomes ureter, expanded cranial end becomes renal pelvis.
How do the kidneys Ascent?
Initially lie on either side of bladder and in developing pelvis. Due to growth of lower body they ascend. Lie in upper abdomen (T12-L3)
Ascent stops when come in contact with adrenal glands.
Rotates to hilum faces medially.
What is the bladder?
What is function of detrusor muscle?
Bag of smooth muscle, arranged in spiral, longitudinal and circular bundles = detrusor muscle
* contraction of this muscle is mainly responsible for emptying the bladder during micturition.
Where does the bladder lie?
Midline posterior to pubic bones. Lies anterior to reproductive system and rectum.
What does the trigone of bladder contain?
2 vesicoureteric openings.
- 1-2cm oblique passage through muscular wall
What is defined as being the upper urinary tract?
Anything above the bladder:
- Kidneys - parenchyma, pelvi-calyceal system
- Ureters - Pelvi-uteric junction, ureter, vesicle-uteric junction (valve allows one way traffic)
What is defined as being the lower urinary tract?
- Bladder
- Bladder outflow tract:
- bladder neck
- prostate
- external urethral sphincter/pelvic floor
- urethra
- urethral meatus
- foreskin
- testes
