Principles - The Renal System

Question 1

What is the urinary tract?

Answer 1

Upper
Kidney: produces urine
Ureter: drains urine from kidney to bladder
Lower
Bladder: stores/voids urine 
Urethra: Excretion of urine

Question 2

What is the distal urethra lined by?

Answer 2

Protective stratified squamous mucosa

Question 3

Where is the urinary tract?

Answer 3

In the retroperitoneum

Question 4

In which region/quadrant of the abdomen are the kidneys in?

Answer 4

In the right or left flank
or
Right or left upper quadrant

Question 5

What protects the kidneys?

Answer 5

• being in the retroperitoneum
• vertebral column (transverse processes)
• floating ribs
• skeletal muscles (guarding)
• renal (deep) fascia
• paranephric and perinephric fat
• renal capsule

Question 6

How do the kindeys move with respiration?

Answer 6

They move inferiorly on inspiration then superiorly on expiration

Question 7

Why does the right kidney lie at a slightly inferior level?

Answer 7

Due to the size of the liver

Question 8

What are the structures of the renal hilum?

Answer 8

Right or left renal artery
Right or left renal vein
Right or left ureter

Question 9

What is the blood supply to the kidneys?

Answer 9

Renal artery (right or left)
This is a paired branch of the abdominal aorta

Question 10

What is the venous drainage of the kidney?

Answer 10

renal veins

These drain into the IVC for return to the RA

Question 11

What veins drain into the left renal vein?

Answer 11

left gonadal vein and left suprarenal vein

On the right side these veins drain straight into the IVC

Question 12

How many renal segments are there?

Answer 12

5

Question 13

What is the blood supply to the renal segments?

Answer 13

5 segmental branches arise from each renal artery

Question 14

What does the kidney consist of?

Answer 14

Outer cortex and inner medulla mainly

Question 15

How many pyramids does the inner kidney medulla contain and how many nephrons are in each?

Answer 15

27

Each contains about 50000 nephrons

Question 16

What is the structure of a nephron? (proximal to distal)

Answer 16

glomerulus 
proximal convoluted tubule 
loop of Henle 
distal convoluted tubule 
collecting duct 
(passes into minor calyx)

Question 17

What happens at the glomerulus of the nephron?

Answer 17

Ultrafiltration of the blood arriving via branches of the renal artery

Question 18

How does urine drain from the kidney?

Answer 18

Nephrons collecting duct 
Minor calyx 
Major calyx 
Renal pelvis
Ureter 

Diameter of the tubes is increasing until a constriction at the pelviureteric junction

Question 19

Where are the anatomical sites of ureteric constriction?

Answer 19

1. Pelviureteric junction
2. ureter crossing the anterior aspect of the common iliac artery
3. ureteric orifice opening into the posterior surface of the bladder

Question 20

What are renal calculi?

Answer 20

Stones that can form from urine calcium salts

Question 21

How can ureteric obstruction occur?

Answer 21

1. internal obstruction: renal calculus or blood clot
2. external compassion e.g. expanding tumour

Tends to be felt as renal colic - peristaltic waves, pain that comes and goes

Question 22

What can be stretched to allow the bladder to fill?

Answer 22

The urothelium

Question 23

Where is the trigone located in the bladder?

Answer 23

On the floor of the bladder between the bilateral ureteric and midline urethral orifices

Question 24

What happens on filling of the bladder?

Answer 24

The apex rises but the trigone doesn’t stretch or move which helps to prevent the obstruction of the orifices

Question 25

What contracts to void during micturition (urination)?

Answer 25

The detrusor

smooth muscle within the bladder wall

Question 26

Where are the bladder sphincters?

Answer 26

At the ureteric orifices (detrusor muscle fibres encircle) - prevents reflux of urine into the ureters during micturition

At the bladder neck - internal urethral sphincter - preventing ejaculatory reflux - only present in MALES

Question 27

Describe the journey of sperm through the male reproductive system.

Answer 27

right testis (travels inferior to superior)
right epididymis (travels superior to inferior)
right vas deferens (travels from inferior to superior)
right seminal gland
right ejaculatory duct
prostatic urethra
spongy urethra
external urethral orifice

Question 28

Describe the movement of urine through the male lower urinary tract.

Answer 28

Bladder
Through the internal urethral orifice and internal urethral sphincter 
Prostatic urethra 
External urethral sphincter 
Spongy urethra 
External urethral orifice

Question 29

What can benign (BPH) or malignant enlargement of the prostate gland cause?

Answer 29

Urinary retention - inability to void completed due to obstruction of the prostatic urethra

Question 30

Describe the movement of urine through the female lower urinary tract.

Answer 30

Bladder 
Internal urethral orifice (females do not have an internal urethral sphincter)
Urethra 
External urethral sphincter 
External urethral orifice