Kidney Development and Disease
This page will give you a brief overview of how the kidneys develop, what they do in your body, and what happens when they go wrong.
The developing kidney
The kidneys start developing during embryonic development and continue until the baby is born. This occurs in 3 different stages - pronephros, mesonephros, and the metanephros stages. Nephrogenesis includes the interactions of different proteins and molecules in specific orders. During the pronephros stage, the kidneys are not functional, and different cells arrange themselves into tubes. The mesonephros stage is when the kidney starts to take shape and blood supply first enters the kidney. Finally, during the metanephros stage, the functional units of the kidney called the nephrons start to form and the kidney is almost in its mature form. By the time the baby is born, the kidney has started filtering the fetal blood and producing urine!
What do the kidneys do?
Most people are born with 2 kidneys, which are bean-shaped organs located in the upper abdomen. The kidneys are crucial for the maintenance of homeostasis, the body's internal environment. They do this by secreting hormones to stimulate red blood cell production, control blood pressure, and control blood calcium and salt levels. However, their most well-known job is to filter the blood of waste products and produce urine. The kidneys are rich in blood vessels, including bundles of capillaries called glomeruli (each adult human kidney has around 1 million!). Waste products from the body are filtered out of the blood in the glomeruli into the urinary space, where they travel through the nephron tubules. In the tubules, molecules that we need are reabsorbed back into the blood and more molecules we don't need are secreted. After this, the blood has been freshly cleaned and goes back into the body, while urine is produced and travels to the bladder, ready for excretion!
Award-winning image of kidney tubules, lymphatics and macrophages - taken by Dr Laura Wilson
Chronic kidney disease (CKD) occurs when the kidneys can no longer filter the blood efficiently, meaning waste products build up in the blood, and the body's internal environment is unbalanced. This can be caused by genetic disorders, which patients are born with, or environmental or lifestyle factors, such as viruses, poor diet, or smoking. Examples include polycystic kidney disease, diabetic nephropathy, or systemic lupus erythematosus. CKD costs the NHS millions of pounds every year and is a huge burden on patients' lives. Patients with end-stage kidney disease have to go to the hospital multiple times a week to undergo dialysis, meaning a machine has to clean their blood, while they wait for a kidney transplant, which could take years. The Kidney Development and Disease group is committed to understanding these diseases and developing treatments to improve patient lives.