Question

Maximum amount of ${H_2}O$ could be reabsorbed in which part of the nephron in the presence of vasopressin
(A) Proximal convoluted tubules
(B) Distal convoluted tubule
(C) Loop of Henle
(D) Collecting duct

Answer 1

Hint:Vasopressin or antidiuretic hormone (ADH) or arginine vasopressin (AVP) is a nonapeptide synthesized in the hypothalamus. Vasopressin plays crucial functions in the management of the body’s osmotic balance, blood pressure limitation, sodium homeostasis, and kidney functioning.

Complete answer:
Option (A)Proximal convoluted tubules
The proximal convoluted tubule is covered by simple cuboidal brush border epithelium which improves the surface area for reabsorption. Antidiuretic hormone or vasopressin prevents the unnecessary loss of water through urine. When blood volume is reduced the Vasopressin works on the Proximal convoluted tubule and reasons absolute water reabsorption which boosts blood volume.
Option (B)Distal convoluted tubule
The distal convoluted tubule is the nephron portion that lies shortly downstream of the macula densa. Although small in length, the distal convoluted tubule plays a significant role in sodium, potassium, and divalent cation homeostasis.
Option (C)Loop of Henle
Loop of Henle, an extended U-shaped portion of the tubule that regulates urine within each nephron of the kidney of reptiles, birds, and mammals. The main purpose of the loop of Henle is in the return of water and sodium chloride from urine.
Option (D)Collecting duct
Papillary or collecting ducts are anatomical patterns of the kidneys, recently identified as the ducts of Bellini. Papillary ducts denote the most distal part of the collecting duct. They obtain renal filtrate (precursor to urine) from various medullary collecting canals and vacant into a minor calyx.
Thus, the correct answer is Option A- proximal convoluted tubules.

Note:The solitary most vital impact of the antidiuretic hormone is to maintain body water by diminishing the loss of water in urine. A diuretic is an agent that enhances the rate of urine collection. Injection of small amounts of antidiuretic hormone into an individual or creature outcomes in antidiuresis or diminished formation of urine.