S1) Anatomy of the Urinary System

Question 1

In terms of anatomical relationships, explain why the left kidney is higher than the right kidney?

Answer 1

• The liver (above the right kidney) is larger than the spleen (above the left kidney)
• Hence, the left kidney is higher because the liver pushes the right kidney down

Question 2

At approximately what vertebral level would you expect to find the right and left kidneys respectively?

Answer 2

• Left kidney (T11 - L2)
• Right kidney (T12 - L3)

Question 3

Identify the anatomical relations of the right kidney

Answer 3

4 – Adrenal glands

6 – Duodenum

2 – Hepatic area

7 – Right colon areas

3 – Inferior vena cava

8 – Abdominal aorta

Question 4

Identify the anatomical relations of the left kidney

Answer 4

4 – Adrenal glands

9 – Small bowel

5 – Spleen

10 – Pancreas

7 – Left colon areas

1 – Stomach

11 – Left renal vein

Question 5

Identify the complex layers of fascia and fat surrounding the kidney (deep to superficial)

Answer 5

Question 6

Describe the structure of the following:

• Renal capsule
• Renal fascia

Answer 6

• Renal capsule: tough fibrous capsule
• Renal fascia: encloses the kidneys and the suprarenal glands

Question 7

Describe the structure of the following:

• Perirenal fat
• Pararenal fat

Answer 7

• Perirenal fat: collection of extraperitoneal fat
• Pararenal fat: mainly located on the posterolateral aspect of kidney

Question 8

The renal parenchyma can be divided into two main areas.

Identify these

Answer 8

• Outer cortex
• Inner medulla

Question 9

What are renal pyramids and how are they formed?

Answer 9

The outer renal cortex extends into the inner renal medulla, dividing the kidney into triangular shapes known as the renal pyramids

Question 10

What is the apex of a renal pyramid called?

Answer 10

A renal papilla

Question 11

What is a minor calyx and what does it do?

Answer 11

A minor calyx is a structure that is associated with a renal papilla and collects urine from the pyramids

Question 12

How is a major calyx formed?

Answer 12

Several minor calices merge to form a major calyx

Question 13

Explain the role of the renal pelvis in the kidney

Answer 13

• Urine passes through the major calices into the renal pelvis, a flattened and funnel-shaped structure
• From the renal pelvis, urine drains into the ureter, which transports it to the bladder for storage

Question 14

What is the renal hilum and what does it do?

Answer 14

• A renal hilum is a deep fissure which marks the medial margin of each kidney
• Renal vessels and ureter enter/exit the kidney through this structure

Question 15

Describe the arterial supply of the kidneys

Answer 15

• Receive blood from renal arteries
• Left and right renal arteries arise from the abdominal aorta

Question 16

Identify the following renal vasculature:

Answer 16

Question 17

What is the term used to describe the junction between the pelvis of the kidney and the ureter?

Answer 17

Pelvi-ureteric junction

Question 18

What term is used to describe the junction between the ureter and the bladder?

Answer 18

Vesico-ureteric junction

Question 19

Describe the venous drainage of the kidneys

Answer 19

• Drained of venous blood by left and right renal veins
• Leave the renal hilum and empty directly into the inferior vena cava

Question 20

Describe the lymphatic drainage of the kidneys

Answer 20

Lymph from the kidney drains to the lateral aortic nodes

Question 21

From the hilum, describe the course of the ureter until it enters the bladder

Answer 21

• Renal pelvis narrows to form the ureter (PUJ)
• Ureter descends down abdomen and cross pelvic brim where the common iliac artery bifurcates
• Ureters run down lateral pelvic walls then move anterio-medially towards bladder

Question 22

In females, what does the phrase “water under the bridge refer to?”

Answer 22

The ureter runs underneath the uterine artery

Question 23

There are three common sites of relative constriction where renal stones can get lodged due to the non-uniformity of the ureter lumen.

Identify these sites

Answer 23

• Pelvi-uteric junction (PUJ)
• Vesico-uteric junction (VUJ)
• When ureter enters pelvis and crosses common iliac artery bifurcation

Question 24

How long is the urethra in the adult male and female?

Answer 24

4 cm in females

8 cm in males

Question 25

The male urethra consists of different regions.

Identify them

Answer 25

• Pre-prostatic urethra
• Prostatic urethra
• Membranous urethra
• Penile urethra (aka spongy urethra)

Question 26

Describe the anatomical location of the pre-prostatic urethra

Answer 26

Pre-prostatic urethra lies between the bladder and prostate

Question 27

Describe the anatomical location of the prostatic urethra

Answer 27

Prostatic urethra traverses the prostate

Question 28

Describe the anatomical location of the membranous urethra

Answer 28

Membranous urethra spans from the apex of the prostate to the bulb of the penis (deep peritoneal pouch)

Question 29

Describe the anatomical location of the penile urethra

Answer 29

Penile urethra traverses the corpus spongiosum of penis