Collectively, the materials eliminated from the nephron are called _ a. renin b. electrolytes c. filtrate d. urine
The correct answer and explanation is:
The correct answer is d. urine.
Explanation:
The nephron is the functional unit of the kidney, responsible for filtering blood and producing urine. It performs essential tasks such as filtering out waste products, excess substances, and fluids from the bloodstream while retaining needed components like proteins and blood cells.
Here’s a step-by-step breakdown of the process:
- Filtration: Blood enters the nephron through the glomerulus, where water, ions, glucose, amino acids, and waste products are filtered out of the blood plasma. The resulting fluid is called filtrate (answer c), which is an initial product but not what is ultimately eliminated from the body.
- Reabsorption and Secretion: As the filtrate moves along the tubules of the nephron, useful substances such as glucose, certain ions (electrolytes), and water are reabsorbed back into the bloodstream. Simultaneously, some additional waste substances and ions may be secreted into the tubule.
- Formation of Urine: After filtration, reabsorption, and secretion, the remaining fluid in the nephron is concentrated and becomes urine. Urine contains waste products like urea, creatinine, excess electrolytes, and water that the body needs to eliminate.
- Excretion: Urine flows from the nephron into collecting ducts, then to the renal pelvis, ureters, bladder, and finally is expelled from the body.
Why the other options are incorrect:
- a. renin: Renin is an enzyme secreted by the kidneys that helps regulate blood pressure, but it is not a substance eliminated from the nephron.
- b. electrolytes: Electrolytes are ions like sodium, potassium, and chloride. Some electrolytes are filtered and eliminated, but many are reabsorbed to maintain balance; they are not collectively the eliminated material.
- c. filtrate: Filtrate is the fluid initially filtered from the blood. It contains many substances but is processed further in the nephron before elimination.
Summary:
The nephron filters blood to remove waste products and excess substances, converting filtrate into urine. Urine is the collective term for all materials eliminated from the nephron and excreted from the body. This waste removal is crucial for maintaining the body’s chemical balance, regulating fluid levels, and removing toxins.