Chapter 34, Problem 29A

Summary Introduction

To write:

About the function of kidney in the conservation of water in the body

Introduction:

The excretory system is the system of an organism's body that performs the function of excretion, the bodily process of discharging wastes. Several parts of the body are involved in this process, such as sweat glands, the liver, the lungs and the kidney system. The kidneys maintain homeostasis by removing wastes and excess water from the body and by maintaining the pH of the blood. The kidneys are the major excretory organ in the body. It is a bean-shaped organ that is involved in urine formation performs filtration of blood.

Answer to Problem 29A

Correct answer :

The correct answer is option (C) Reabsorption.

Explanation of Solution

Explanation/justification for the correct answer :

Option (C) Reabsorption. Water and substances dissolved in the water, such as the nitrogenous waste product called urea, are pushed through the capillary walls into the Bowman’s capsule. The filtrate collected in the Bowman’s capsule flows through the renal tubule that consists of the convoluted tubule, the loop of Henle, and the collecting tubule. Much of the lost water and useful substance such as glucose and minerals are reabsorbed back into the capillaries surrounding the renal tubule. This process is called reabsorption. So, the correct answer is option (C).

Explanation for incorrect answer :

Option (A) absorption. The major function of the kidney is the reabsorption from the filtrate into the blood of water and small molecules and the secretion of waste from the blood into the urine. Therefore, absorption is not a function of the kidney. So, this is an incorrect option.

Option (B) filtration. Filtration is the process of removing unwanted substances. It is the function of the kidney but conservation of water is the process of reabsorption where the lost water is reabsorbed back into the capillaries. So, this is an incorrect answer.

Option (D) breathing. Breathing is the process of exchanging gas between the atmosphere and the body.It is a part of the respiratory system. So, this is an incorrect answer.