Chapter 26, Problem 1RAC

Summary Introduction

Introduction:

The urinary system is a specialized organ that supports the exchange of water and electrolytes between the body and the environment. It includes kidneys, ureters, bladder, and urethra which perform a function like passage, storage and voiding of urine. It helps the body to get rid of liquid waste (urea) and also control the blood pressure and pH.

Answer to Problem 1RAC

The correct answer is option (d) regulation of vitamin A synthesis.

Explanation of Solution

Explanation/justification for the correct answer:

Option (d). Regulation of vitamin A synthesis. Vitamin A is taken from the food it is not synthesis by the body, whereas kidney plays a very important role in the synthesis of vitamin D. it is needed for controlling blood calcium. So, the correct answer is option (d).

Explanation for incorrect answer:

Option (a). Regulation of blood volume. It helps in regulating the blood volume by secreting and absorbing the essential components (water, solute). It helps in producing either a large volume of diluted urine or a small volume of concentrated urine. So, this is an incorrect option.

Option (b). Regulation of solute concentration in the blood. It helps in regulating the solute concentration by reabsorbing solutes like sodium, chloride, potassium, calcium, and carbonates ions. So, this is an incorrect answer.

Option (c). Regulation of pH of the extracellular. The pH of the blood is regulated by secreting a variable amount of hydrogen ion. So, this is an incorrect answer.

Option (e). Regulation of red blood cell synthesis. Kidney secretes a hormone called erythropoietin which helps in regulating the synthesis of red blood cells in the bone marrow. So, this is an incorrect answer.