Dissection of a kidney
Introduction:
Kidneys are paired organs which in mammals are located close to the dorsal wall of
the abdominal cavity on either side of the vertebral column. They function to filter out
metabolic wastes such as urea and some salts and to regulate the water and salt
balance in the body.
Background Information:
 Emerging from the kidney are three tubes:
The renal artery, a narrow tube with thick elastic walls which takes blood into the
kidney.
The renal vein, a wide tube with limp walls which carries blood out of the kidney. It
may contain dark, clotted blood.
The ureter, a tough, white tube which carries urine from the kidney to the bladder.
 Three areas can be distinguished inside the kidney – the cortex, the medulla and
the pelvis.
Purpose:
To examine the external and internal structure of a kidney and relate it to its function.
Requirement:
Sheep’s kidney
Dissecting tray
Scissors
Sharp scalpel
Forceps
Prepared microscope slide
OR
Photomicrograph of kidney tissue
Procedure:

Remove any fatty surrounding tissue from the kidney taking care not to damage
any of tubes emerging from the concave surface.
Gently separate, as much as possible, the three tubes.
Try to identify the artery, vein and ureter.

Cut the kidney in half lengthways starting from the concave side just to one side
of the centre line. Leave the tubes intact in one side of the dissection.

Observe the internal appearance of the kidney. Identify the cortex, medulla and
pelvis.

Dispose of the dissected kidney and clean instruments.

Now observe the slide or photomicrograph of kidney tissue.
In the kidney cortex are located the filtration units of the nephrons, known as
Bowman’s capsule. Each encloses a clump of blood capillaries called the
glomerulus. Water containing wastes such as urea and useful substances such as
glucose is forced into the hollow capsule from the blood in the glomerulus. From
the capsule it travels through a long, winding kidney tubule surrounded by blood
capillaries. The useful components of the filtrate are reabsorbed into the blood
stream. The filtrate, now called urine, runs by way of collecting tubules to the
pelvis of the kidney, thence by way of the ureter to be stored in the bladder.
Discussion:
1.
2.
3.
4.
What is the purpose of the fat that surrounded the kidney?
How did you distinguish between the renal artery and vein?
Which area of the kidney contains the Bowman’s capsules?
Describe the difference in composition between blood in the renal artery and
blood in the renal vein.
5. Where are the wastes filtered from the blood?
6. What is the function of the ureter?