Final answer:
The nephron is the key functional unit of the kidney, responsible for filtering blood and forming urine through processes of filtration, reabsorption, and secretion. It consists of the renal corpuscle and renal tubule, as well as an associated capillary network that facilitates the transfer of substances between the blood and filtrate.
Step-by-step explanation:
The nephron is the fundamental functional unit of the kidney, involved in the complex process of filtering blood and forming urine. This microscopic structure consists of several parts, with the main components being the renal corpuscle and the renal tubule. The renal corpuscle includes the glomerulus, a tuft of capillaries, which functions in conjunction with Bowman's capsule to filter blood based on particle size. Once the filtration process is complete, the resulting filtrate passes into the renal tubule.
The renal tubule extends from Bowman's capsule and is responsible for further processing the filtrate. Throughout this long and coiled structure, substances are reabsorbed into the bloodstream, and others are secreted into the fluid, which ultimately results in the formation of urine. The urine then moves on to the collecting ducts, where additional water may be absorbed, and finally exits the kidney for excretion.
Nephrons are crucial in maintaining the body's homeostasis, performing several key functions, including filtration, reabsorption, secretion, and various secondary functions such as blood pressure regulation, red blood cell production, and calcium absorption. The entire process is critical for balancing plasma to homeostatic set points and removing potential toxins through urine. The nephron's sophisticated system of capillaries originates from the cortical radiate arteries, forming a network that is essential for the exchange of water and solutes with the blood.