KIDNEY

Each kidney is surrounded by a renal cortex and a renal medulla.

The functional units of the kidneys are the nephrons. The nephrons consist of a coiled renal tubule and a vascular network of peritubular capillaries to filter waste, macromolecules and ions from the blood and form the urine. Each kidney consists of approximately 1 million nephrons.

The kidneys receive their blood supply from the renal arteries, which are fed from the abdominal aorta.

The main functions of the kidney are:

·         Elimination of waste products (e.g. urea, creatinine) and excess body water

·         Homeostatic functions such as:

o    regulation of electrolyte balance

o    maintenance of acid-base balance

o    regulation of blood pressure

·         Production of hormones e.g. erythropoetin, renin, calcitriol