A01 Topography of the Kidneys and Renal Tract

Question 1

List the components of the urinary system.

Answer 1

1 - 2 kidneys.

2 - 2 ureters.

3 - Urinary bladder.

4 - Urethra.

Question 2

What are rugae?

Answer 2

Folds seen in the empty bladder.

Question 3

Which type of epithelium lines the urinary bladder?

Answer 3

Transitional epithelium.

Question 4

What are ureters?

How do they function?

Answer 4

• Long muscular tubes that convey urine from the kidneys to the bladder.
• They do this by peristalsis.

Question 5

How does the bladder change in size during filling?

Answer 5

• The base of the bladder changes little during filling.

- The bladder instead extends superiorly towards the pelvic brim.

Question 6

Which tissue covers the fundus of the bladder?

Answer 6

Peritoneum that is reflected from the internal aspect of the anterior abdominal wall.

Question 7

What lies below the bladder in males and females?

Answer 7

• In females, the bladder sits on the pelvic floor at the urethra.
• In males, the prostate gland separates the bladder from the pelvic floor, and surrounds the urethra.

Question 8

Which sphincter of the urinary system is innervated by the somatic nervous system?

Answer 8

The external urethral sphincter.

Question 9

Between which vertebral levels do the kidneys lie?

Answer 9

• The kidneys lie between vertebral levels T12-L3.

- However, the right kidney is slightly lower.

Question 10

What are the hilums of the kidneys?

Answer 10

The area through which blood vessels, nerves and lymphatic vessels enter and leave the kidneys.

Question 11

Describe the gross blood supply to the kidney.

Answer 11

• At the L1/L2 vertebral levels just below the origin of the superior mesenteric artery, the abdominal aorta gives rise to the renal arteries.
• The left renal artery passes behind the left renal vein.
• The right renal artery passes behind the inferior vena cava and the right renal vein.
• The right renal vein receives blood directly from the right kidney and has no other branches, whereas the left renal vein has 3 other tributaries:

1 - Left gonadal vein.

2 - Left lumbar vein (there are other lumbar veins that branch directly from the vena cava).

3 - Left adrenal vein.

Question 12

Describe the course of a renal artery as it supplies the structures throughout a kidney.

Answer 12

1 - The renal artery enters the kidney through the hilum.

2 - It bifurcates at each lobe to form the interlobar arteries, which ascend the renal pyramids.

3 - The interlobar arteries then bend around the top of the renal pyramid, where they are known as arcuate arteries.

4 - The arcuate arteries give small branches known as interlobular arteries that project into the cortex. These supply the renal corpuscles.

Question 13

What is the renal capsule?

What is its function?

Answer 13

• The renal capsule is a tough fibrous layer surrounding the kidney that is covered in a layer of perirenal fat known as the adipose capsule.
• It supports the kidney mass and provides protection from trauma.

Question 14

List the 3 regions of the ureters where renal calculi are most likely to get stuck.

Why are these common sites of blockage?

Answer 14

1 - The pelviureteric junction.

2 - The point where the ureter passes over the pelvic brim as it crosses the common iliac artery.

3 - The vesico-ureteric junction.

• These are common sites of blockage because they are the sites where the ureters are thinnest.

Question 15

Where would pain be referred to if a renal calculus became stuck at the pelviureteric junction?

Answer 15

• Calculi at the pelviureteric junction cause deep flank pain due to distension of the renal capsule.
• Pain is without radiation to the groin.

Question 16

Where would pain be referred to if a renal calculus became stuck at the point where the ureter passes over the pelvic brim?

List 2 other conditions that this pain might mimic.

Answer 16

Calculi at the point where the ureter passes over the pelvic brim cause pain between the umbilicus and groin.

• This pain may mimic:

1 - Appendicitis (right hand side).

2 - Diverticulitis (left hand side).

Question 17

Where would pain be referred to if a renal calculus became stuck at the vesicoureteric junction?

List the nerves that refer the pain to these sites.

Answer 17

• Calculi at the vesicoureteric junction cause pain radiating to the groin or testicle / labia majora.
• Referred pain to these sites is conveyed by the ilioinguinal and genitofemoral nerves.

Question 18

What is the ureterorenal reflex?

Answer 18

Pain from the ureters causes a sympathetic reflex back to the kidney to constrict the renal arterioles, thereby decreasing urine output from the kidney.

Question 19

What are the spinal nerve roots of the sensory nerves supplying the ureters?

Answer 19

T11-L2.

Question 20

List the 5 main muscles that comprise the posterior abdominal wall.

Answer 20

1 - Diaphragm.

2 - Psoas major.

3 - Psoas minor.

4 - Iliacus.

5 - Quadratus lumborum.

Question 21

Describe the arterial supply to the ureters.

Answer 21

• The upper ureter is supplied by the renal artery and by branches from the gonadal artery and aorta directly.
• The middle ureter is supplied by the common iliac and gonadal arteries.
• The distal ureter is supplied by branches of the common iliac and internal iliac branches, particularly uterine and superior vesical arteries.

Question 22

Define hysterectomy.

Answer 22

Removal of the:

1 - Uterus.

2 - Uterine tubes.

3 - Ovaries.

4 - Cervix.

Question 23

List 3 pouches found in the pelvis of males and females.

What is the clinical significance of these pouches?

Answer 23

Males:

1 - Rectovesical pouch.

Females:

2 - Rectouterine pouch (pouch of Douglas).

3 - Vesicouterine pouch.

• These pouches are sites where fluids and infection can collect.
• The rectouterine pouch (pouch of Douglas) can be used for peritoneal dialysis in end-stage kidney failure.

Question 24

What is the trigone?

List the structures that form the corners of the trigone.

Answer 24

• The trigone is a smooth triangular region of the internal urinary bladder.
• It is formed by the two ureteric orifices and the internal urethral orifice.

Question 25

Where is the bladder located in adults when empty and full?

Where is the bladder located in infants?

Answer 25

• When empty, the bladder is located in the true pelvis.
• When full, the bladder extends partially into the false pelvis.
• In infants, the bladder is undescended and is therefore located in the abdomen until puberty.