Anatomy and Histology of Urinary System Flashcards
What makes up the urinary system?
Kidneys
Ureters
Urinary bladder
Urethra
Functions of the kidneys
Removes metabolic waste from the blood by filtration and excretion
Regulates BP (by renin angiotensin mechanism)
Regulates plasma concentrations of electrolytes
Helps to stabilise pH
Conserves valuable nutrients
Reabsorption of small molecules (amino acids, glucose and peptides)
Produces erythropoietin
What is erythropoietin?
A stimulant of RBC production by bone marrow
What is the functional unit of the kidney?
Nephron
What makes up a nephron?
Renal corpuscles and renal tubules
What makes up a uriniferous tubule?
Nephron and collecting duct
What makes up renal corpuscules?
Glomerulus and bowens capsule
Two parts of the kidney
Cortex
Medulla
What is found in the cortex of the kidney?
Renal corpuscles
Proximal convoluted tubules (cuboidal and microvilli)
Distal convoluted tubules (cuboidal)
Collecting tubule (cuboidal)
What is found in the medulla of the kidney?
Proximal convoluted tubules
Distal convoluted tubules
Loop of Henle (thin segment; squamous epithelium)
Epithelium of the ureter
Transitional epithelium
Shape of the ureters lumen
Star shaped
Muscle of the ureter
Inner longitudinal smooth muscle
Outer circular smooth muscle
What is an important marker of chronic kidney disease?
High protein (albumin) level in urine GFR by serum creatinine
What does GFR stand for?
Glomerular filtration rate
Where do the kidneys lie?
T12 - L3
Peritonisation of the kidneys
Partly peritonised
Which kidney is lower and why is this?
Right
Due to liver
Layers of the capsule and fascia of the kidney
- Kidney
- Renal capsule
- Perirenal fat
- Renal fascia
- Pararenal fat
Where is the perirenal fat found?
Between renal capsule and renal fascia
Where is the pararenal fat found?
Outside of the renal fascia
From medulla to ureter, what are the structures?
Medulla -> pyramid -> papilla -> minor calyx -> major calyx -> pelvis -> ureter
Natural constrictions of the ureter
Passes over the inferior renal pole
Passes behind testicular or ovarian vessels
Crosses over external iliac vessels
Transverses the bladder wall
Order of the vessels in the kidneys anterior to posterior
VAP
- vein
- artery
- pelvis
What are the renal arteries a branch of?
Abdominal aorta
How many renal arteries do you have?
1 on each side
Branches of each renal artery
Segmental (5x)
Interlobar (supply each nephron)
Arcuate (pass around circumference)
How many renal veins do you have?
1 on each side
Where do the renal arteries drain to?
IVC
Lymphatic drainage of the kidneys
Lateral aortic lymph nodes
Nerve supply to the kidneys
Renal plexus
- sympathetic T10 - L1
- sensory afferent
What is the trigone and where is it found?
Smooth triangle of the bladder
Function of the rugae of the bladder
Allows the bladder to extend to large volumes
Where does the median umbilical ligament come from?
Embryonic urachus
What surface of the bladder is peritonised?
Superior
Arterial supply to bladder
Branches of internal iliac arteries
Venous drainage of bladder
Tributaries of the internal iliac veins
Lymphatic supply of bladder
External iliac to the suprapubic part
Internal iliac to the infrapubic part
Nerve supply of the bladder
Sympathetic T11-L2 (constrict internal urethral sphincter)
Parasympathetic S2-S4 (motor to detrusor muscles)
Afferent/sensory and pain and distention - parasympathetic fibres mainly
Somatic; pudendal nerve (external urethral sphincter)
Parts of the male urethra
- Pre-prostatic / intramural
- Prostatic
- Membranous / intermediate
- Spongey / penile
What is found in the deep perineal pouch?
External urethral sphincter
Bulbourethral gland/duct
What type of muscle is found in the external urethral sphincter?
Skeletal muscle
What is the narrowest part of the male urethra?
Membranous
What is the widest part of the male urethra?
Prostatic
What is the longest part of the male urethra?
Spongey
