Question

............... are the structural and functional unit of filtration in the kidney.
(a) Ureter
(b) Urethra
(c) Neurons
(d) Nephrons

Answer 1

Nephrons are a kidney's structural and functional filtration unit that helps to filtrate, reabsorb, and secrete. Ureters are thin muscular tubes that reach into the urinary bladder from the kidney and contain urine. The urethra is a canal that holds and expels urine from the bladder out of the body.

Complete step by step answer:
The nephron is the functional unit of the kidney that in the process of eliminating waste and excess substances from the blood, actually produces urine. Each human kidney has approximately 1,000,000 nephrons. A long tubule, or exceptionally fine tube, is about 3055 mm (1.22.2 inches) long for each nephron in the mammalian kidney. This tube is closed, extended, and folded at one end into a double-walled cuplike system. This structure known as the renal corpuscle capsule or Bowman's capsule comprises a cluster of capillaries of microscopic blood vessels called the glomerulus. Together the capsule and glomerulus constitute the renal corpuscle. Via tiny arteries called arterioles, which enter and exit the glomerulus through the open end of the capsule, blood flows into and away from the glomerulus. Fluid filtered from the blood of the glomerulus in the renal corpuscle through the inner wall of the capsule and into the tubule of the nephron. As this philter moves through the tubule, the secretion of certain substances into it and the selective reabsorption of water and other constituents from it change its composition. Urine, which is transmitted through the renal pelvis via the collecting tubules, is the final product.

Additional information:
The primary role of nephrons is to extract all waste products from the blood, including solid waste and other excess water, to turn blood into the urine, to reabsorb, to secrete, and to excrete various substances. The small molecules are transferred through the glomerular capsules and flow through a winding series of tubules as the blood flows through the glomerulus with high pressure. With the exception of glucose, water, and other beneficial molecules called ass ultrafiltrate, the cell present in each tube absorbs numerous molecules. They become more and more hypertonic as the ultrafiltrate molecules migrate down the tubules, resulting in more water being removed from the ultrafiltrate before the nephrons exit. Via renal blood vessels, which are free of toxins and other excess substances, the blood surrounding the nephron flows back into the body. The ultrafiltrate obtained is urine that passes down to the bladder through the collecting duct, where it will be collected and released via the urethra.

So, the correct answer is ‘Nephrons’.

Note:
The kidney's functional unit is the nephron. Each kidney is made up of millions of nephrons, which play a major role in blood filtration and purification. The nephron, namely the glomerulus and the renal tubule, is divided into two sections and helps to eliminate excess waste from the body.