MLT GlobeAnatomy: Urinary system
16 Anatomy MCQs on Urinary system with answers and explanations.
Which microscopic unit of the kidney, about one million per kidney, filters blood and forms urine?
The nephron (renal corpuscle plus tubule) is the structural and functional unit. The glomerulus and loop of Henle are only parts of it; collecting ducts are shared by many nephrons.
Vessels, nerves and the ureter enter or leave the kidney through a notch on its concave medial border. This is the:
The renal hilum is the medial indentation for the renal artery, vein and pelvis. Cortex and medulla are internal regions; the capsule is the outer covering.
Urine from the minor and major calyces collects in which funnel-shaped chamber before entering the ureter?
Calyces drain into the renal pelvis, which narrows into the ureter. Papillae are tips of medullary pyramids; the hilum is the medial notch.
Which organ lies behind the peritoneum (retroperitoneal)?
The kidneys lie on the posterior abdominal wall behind the parietal peritoneum. The stomach, jejunum and most of the liver are intraperitoneal.
A kidney glomerulus is best described as a tuft of which type of vessel?
The glomerulus is a capillary tuft between the afferent and efferent arterioles, where filtration occurs. Its vessels are not arteries even though arterioles feed and drain it.
On an abdominal X-ray, the kidneys normally lie between which vertebral levels?
Each kidney lies retroperitoneally from about the level of T12 to L3, the right slightly lower because of the liver.
Which structure is NOT itself an organ of the urinary system?
The urinary system consists of the kidneys, ureters, bladder and urethra. The renal artery is a blood vessel of the circulatory system that supplies the kidney.
What is the approximate length of the adult male urethra?
The male urethra is about 18–20 cm long, compared with about 4 cm in females, so a longer catheter is needed.
The renal medulla consists mainly of which structures?
The medulla is formed by 8–18 renal pyramids containing loops of Henle and collecting ducts. Renal columns are cortical extensions between pyramids.
The smooth triangular area of the bladder wall between the two ureteric openings and the urethral opening is the:
The trigone has a smooth mucosa firmly attached to muscle, unlike the folded remainder of the bladder lining.
Plasma is filtered in the renal corpuscle across the glomerulus into which structure?
Filtrate passes from glomerular capillaries into Bowman's capsule, then the proximal tubule. This filtration rate is estimated by creatinine-based eGFR.
Which surface of the urinary bladder has a peritoneal covering?
Peritoneum covers only the superior surface of the bladder (and part of the posterior surface in males). The anterior and inferolateral surfaces are extraperitoneal.
Fenestrated capillaries suited to rapid filtration are characteristic of which site?
Glomerular capillaries have pores (fenestrations) allowing high filtration. Muscle and lung capillaries are continuous; the spleen has discontinuous sinusoids.
Which set of structures passes through the hilum of the kidney?
From front to back the hilum transmits the renal vein, renal artery and renal pelvis, along with lymphatics and nerves.
A ureteric stone is most likely to lodge at which point of natural narrowing?
The ureter narrows at the pelviureteric junction, at the pelvic brim, and at the vesicoureteric junction; the latter is the tightest and a common stone site.
The permanent kidney (metanephros) develops from the ureteric bud together with which tissue?
The metanephric blastema forms the nephrons, while the ureteric bud forms the collecting system. The urogenital sinus forms the bladder.