Flashcards in Renal Deck (128)
What is the anatomical difference between the left and right gonadal veins?
-Left goes into left renal vein then to ivc
-Right goes straight into IVC
Describe the anatomical relationships between the renal vessels and ureter
-Renal vein most superficial, then renal artery then ureters
What is the trigone of the bladder and state its significance
-A triangle area between the two ureter orrifices and the internal urethral meatus.
-It is a non-distensible area which signals to the spinal cord when stretched
Name the segments of the male urethra
Which segment possesses the most resistance on passage of a catheter?
Give 3 common places a renal stone can get stuck
-Pelviuretic junction (narrowing of the renal pelvis as it transitions into ureter)
What is the main function of the PCT?
-Site of major reabsorbtion of Na, K, bicard, glucose, amino acids and water
Briefly describe the development of the kidney
-First pronephros forms from intermediate mesoderm and develops a duct which extends caudally
-Mesonephros develops and commandeers pronephrotic duct. Caudal development continues until it makes contact with cloaca and ureteric buds begin to sprout
-Ureteric buds make contact with metanephric blastema driving development into metanephros which is fuctioning fetal kidney
What is the urogenital ridge?
-Area of intermediate mesoderm on the posterior abdominal wall which gives rise to the embryonic kidney and gonads
Describe how the ureteric bud develops into collecting system of the kidney
-Makes contact with the metanephric blastema and grows into it by expanding and branching to form the collecting tubules, renal pyramids, major and minor calyx, renal pelvis and ureter
What is renal agenesis and give one physiological cause of this
-Complete absence of a kidney
-Failed interaction of ureteric bud
What is a wilms tumour?
-Congenital tumour of the kidney
Describe one possible consequences of duplication defects of the ureteric bud
-Incontinence if complete duplicate ureter joins after external urethral sphincter
What is the function of the urorectal septum?
-Separates urinary tract from gut tube
What does the urogenital sinus develop into? How is it connected to umbilicus? Describe a pathology which is related to this
-Upper portion of UGS creased bladder and urethra. Lower portion creates lower 2/3 vagina in females and prostate/spongy urethra in males
-The allantois originally filters liquid waste via umbilicus in exchange with mother and it develops into urachus which is a fibrous remnant of allontois.
-A patent urachus is failed regression of the patent tube into the medial umbilical ligament. This can lead to urine leaking out through umbilicus
Describe the layers of the renal corpuscle which make the filtration barrier
-Fenestrated capillary endothelium
-Visceral layer of bowmans capsule
What is the juxtaglomerular apparatus made up off and what is its function?
-Macula densa of DCT
-juxtaglomerular cells of afferent arteriole
-Extraglomerular mesangial cells
-Tubuloglomerular feedback -> Detects NaCl conc as a way of interpreting GFR. This results in either prostaglandin and renin secretion if decreased or adenosine secretion if increased leading to vasodilation and RAS activation or vasoconstriction respectively.
How do the collecting ducts form the minor calyx?
-Merging collecting ducts form renal pyramids which form renal papillae -> renal calyx
What epithelium lines the bladder and ureters?
Describe the charge on the glomerular basement membrane and state how this helps filtration
-Repels negatively charged proteins so even if they are small they may not pass through, attracts positively charged proteins so larger ones may pass through
Describe the forces which drive filtration
-Capillary hydrostatic pressure
-Bowmans capsule hydrostatic pressure
-Capillary oncotic pressure
Explain how autoregulation of the kidney works?
-Within 80-180mmHg range in BP the kidney can control its own perfusion pressure and thus GFR by detecting changes in stretch of smooth muscle. An increase in BP causes an increased delivery of blood to the kidney -> afferent vasoconstriction to reduce blood vol and maintain perfusion pressure and GFR. Decreased BP causes afferent vasodilation maintaining bp and GFR.
Which capillary is wider afferent or efferent? How does efferent constriction effect pressure in the glomerulus?
-Increases hydrostatic pressure
Why is water readily absorbed in the peritubular cappilaries of cortical nephrons?
-They have a high oncotic pressure
Describe Na and water resorption in PCT. Which important molecule is co-linked with Na resorption in pct and how?
-NaKATPase sets up Na gradient
-Na moves down conc gradient across apical membrane
-Glucose -> uses the Na gradient to move glucose against its concentration gradient by using SGLTs
In which part of the lumen does secretion of H, K and organic cations occur?
How do you calculate filtered load?
-Plasma conc of substance(mg/ml) x GFR(ml/min) = x mg/min
Why can creatinine be used to calculate GFR? What would be an alternative in a hospital setting? How is GFR calculated?
-Freely filtered, not reabsorbed and not secreted
-[urine] x [urine volume]/[plasma]
What is renal clearance?
-The volue of plasma which is totally cleared of a substance by the kidneys per unit time
How do you calculate eGFR?
-(140-age) x mass(kg) x 1.23(men) or 1.04(women)/serum creatinine