Final answer:
The urinary system, inclusive of the kidneys, nephrons, ureters, bladder, and urethra, serves to filter the blood, maintain electrolyte balance, and expel waste through urine. The nephrons are key units in the kidneys that perform blood filtration. Renin, produced by the kidneys, helps regulate blood pressure.
Step-by-step explanation:
Nephr/o and ren/o are root words that reference the kidney, which is a vital component of the urinary system. The urinary system's primary function is the filtration of blood to maintain water and electrolyte balance and the elimination of waste through urine. A core element of this system is the nephron, which is the kidney's microscopic structural and functional unit tasked with blood filtration and urine formation. The pair of kidneys contains over a million nephrons each. Blood enters the kidney via the renal artery, which branches into capillaries intimately associated with nephrons, allowing for efficient filtration.
The filtered fluid, now called filtrate, makes its way through the nephron tubules, ultimately concentrating into urine. That urine is collected in the urinary bladder via the ureters and is then excreted out of the body through the urethra. This process is crucial for removing metabolic wastes and excess substances, ensuring homeostasis. Renin, an enzyme produced by the kidneys, plays a significant role in regulating blood pressure, further underscoring the importance of this organ system.