Final answer:
The kidneys are the central organs of the urinary system, responsible for filtering blood, removing waste, and maintaining water and electrolyte balance. They produce urine, which is carried to the urinary bladder by the ureters and later expelled from the body via the urethra.
Step-by-step explanation:
The kidneys are the central organs of the urinary system and are responsible for filtering wastes from the blood. The urinary system comprises four main components: the kidneys, ureters, urinary bladder, and urethra. The primary function of the kidneys is to filter blood and form urine, which involves removing waste products and excess water from the bloodstream.
The paired kidneys are two bean-shaped organs located near the middle of the back, just below the ribcage, each containing over a million tiny filtration units called nephrons. The nephrons work in concert with a specialized capillary bed called the glomerulus to filter the blood, ensuring that wastes, concentrate to form urine. This urine then travels through the ureters to be stored in the urinary bladder and subsequently excreted from the body through the urethra.
Overall, the kidneys play a crucial role in the urinary system by maintaining the body's water and electrolyte balance, as well as filtering blood and excreting waste in the form of urine.