Urinary Flashcards
The anatomical position of the prostate
Inferior to bladder, superior to the external urethral sphincter. Anterior to the ampulla of the rectum.
The levator ani muscles lie inferolaterally
The anatomical position of the kidney
Retro peritoneal in the the paravertebral channel
Right T12-L3.
Left T11-L2
The course of the ureters
From kidney pelvic inferiorly along psoas major. They cross the pelvic brim by the bifurcation of the common iliac artery. They run along the lateral pelvic wall. At the level of the Ischeal spine they turn obliquely and enter the bladder posteriolaterally. 2cm above the ischeal spine they pass the ovarian artery. Vas deferens found by the volvoureteric junction.
The renal blood supply
Renal artery - segmental artery (3) - interlobar arteries- arcuate arteries- interlobular arteries (90 deg) - afferent arteries
Anatomical position of the bladde
Anterior of the pelvic cavity. Posterior to the pubic symphysis and bone
Explain the pronephros, Mesonephron and it duct and the metanephros.
Pronephros forms in intermediate mesoderm in cervical regions. It’s duct grows caudally and triggers the growth of the mesonephros. Week 4 then regresses
Mesonephros grows caudally week 4 to pronephros, it’s duct grows caudally and joins to the cloaca. Regresses week 8. Mesonephros forms in the urogenital ridge and contains nephrotomes
Urogenital ridge forms on either side from intermediate mesoderm created by the growth of the mesonephros.
The ureteric bud grows from its ducts and joins the metanephric tissue cap. The ureteric bud then stimulates it’s growth. Metanephros is functional from the first trimester
The positional changes of the kidney and problems that can occur
And the body grows caudally the kidneys rise cranially respectively. The blood supply therefore continually regresses and regrows at different parts of the abdominal aorta known as accessory renal arteries. There is lateral displacement so that the kidneys meet the adrenal glands at a 90 degree angle. The kidneys ascend close to each other and this can result in their fusion and as a result horseshoe kidney which can get trapped under the inferior mesenteric artery. The kidney may also have collateral blood supply.
Grow through arterial fork formed by umbilical arteries but one can fail to do so and so becomes a pelvic kidney
Formation of the bladder and urethra
The urorectal septum (mesoderm) grows and divides the cloaca into the urogenital sinus and the anal canal.
The cranial 2/3rds of the urogenital sinus become the bladder and the bottom parts into the pelvic (urethra) and phalic (spongy urethra).
The primitive bladder grows and absorbs the mesonephric duct so that it enters separately to the ureters (later becomes the vas deferens or regresses.)
Ectopic ureteral orifaces/ duplication defects
Do not join bladder but join vagina or urethra. From splitting of ureteric bud.
Urachal abnormalities
Patent urachus
Uracheal cyst
Presents with BPH
Common fistulae?
Exstrophy of bladder- failed reinforcement of cloacal membrane by mesoderm so opens onto abdominal wall.
Hypospadias- defect in folds of urethra so they open onto ventral surface rather than glans of penis.
Identify histological structures of the kidney nephron
Bowman’s capsule- vascular pole extra glomerular mesangial cells of JA. Urinary pole. Capillaries have fenestrated endotheliums. Podocytes have foot processes making slits. Shared basement membrane
PCT - simple cuboidal with brush boarder
Pars recta (straight part)
Thin AL - simple squamous
Tick AL- cuboidal no bb, with tAL, CD and VR in medulla.
DCT- cuboidal, larger lumen than PCT, more mitochondria
CD- larger lumen
Identify ultra structure of ureters
Urothelium
2 layers - circular and longitudinal. Extra layer for final 1/3
Identify ultra structure of bladder
Urothelium
LP
3 layers: spiral, longitudinal and circular
Adventitia
Describe glomerular filtration
Through glomerulus, around 20% (filtration fraction GFR/ RPF)
Depends on hydrostatic pressure diff and osmotic pressure (proteins).
Describe reabsorption in the PCT including OC
Basso lateral:
Na pump
Apical:
NHX
Symporters (glucose, aas, vitamins)
Secretion of Organic anion/cation exchangers with H+ (TM) they enter cells via facilitated diffusion and electrical gradient from Na pump at Basolateral membrane..
Describe reabsorption in TAL
Apical:
NaKCl2
Rom K (back in)
Basolateral:
NaKATP
Describe reabsorption in DCT
Apical: Thiazide: Na/ Cl symporter Ca? Basolateral: NaKATP
Reabsorption CD
Apical:
ENaC
Basolateral:
Na pump
Aquaporin 2
Describe TGF
Increase in GFR = increase in NaCl in DCT
Detected by Macula densa via Nakcl2
Stimulates juxtaglomerular cell to Secrete adenosine to constrict afferent arteriole or prostaglandins to dilate.
Describe secretion
Secretion of K so NaKCl2 can work and maintain. Charge.
Secretion of H+ for HCO3 reabsorption
Organic cations/ anions via baso OCT and luminal anti porter with H+
Describe and calculate clearance, how is it useful
The volume of plasma from which a substance has been completely removed
=(urine conc x urine flow)/ plasma conc
Glucose is 0
Inulin is 125 (not secreted or reabsorbed) = GFR
PAH all is secreted so clearance (ml/min) = RPF (90%)
How are GFR and clearance related
The higher the GFR then the higher the clearance.
Increased by TM- only so much can be reabsorbed.
How do the kidneys Handel sodium in order to change ECF volume. Absorption of sodium and H2O in kidney
Absorb more to increase ECF Na Vs H20 Proximal tub 67 vs 65 LOH 25 vs ? DCT 5 vs 0 Cd 3 vs 5-24