The Kidneys

• The left kidney is positioned higher than the right kidney to allow room for the liver.
• Sitting on top of the kidneys are the adrenal glands. They release adrenaline, the fight or flight hormone.

Kidney Structure:

• The outer layer of the kidney is called the cortex.

• The inner layer of the kidney is called the medulla.

• The kidneys are not protected by the ribcage. They are surrounded by a thick layer of fat for protection.

  
  • Renal artery: supply blood to the kidneys.
  • Renal vein: carries blood from the kidney to the heart.

Functions of the Kidneys

1. Excretion is the main function of the kidneys. They filter waste (urea, salts, water) from the blood to form urine.
2. Osmoregulation: the kidneys balance water and salt content in the body.
3. pH control, by making urine more acidic or alkaline as needed.
4. Hormone production: the kidneys produce a hormone that stimulates the production of red blood cells.

Kidney Failure

• If the kidneys fail to produce urine properly, it can lead to kidney failure. In such cases, dialysis may be necessary.
• Dialysis involves using a machine to filter the blood outside the body.
• Blood is removed from the body and passed through a dialysis machine which filters out waste products and excess water.
• The clean blood is then returned to the body.
• This process is time-consuming and must be done at least three times a week.