Question

Complete 4. the second column in Table 16.4, page 220. Use an X to indicate that the substance is at the locations noted. Tubular Reabsorption 1. When the filtrate enters the proximal convoluted tubule, it contains glucose, amino acids, urea, water, and salts. Some water and salts remain in the nephron, but enough are passively reabsorbed into the peritubular capillary to maintain blood volume and blood pressure. Use this information to state a way kidneys help maintain homeostasis 2. The cells that line the proximal convoluted tubule are also engaged in active transport and usually completely reabsorb nutrients (glucose and amino acids) into the peritubular capillary. What would happen to cells if the body lost all its nutrients by way of the kidneys? 3. Which of the filtrate substances is reabsorbed the least and will become a part of urine? Urea is a nitrogenous waste. State here another way kidneys contribute to homeostasis 4. In the list that follows, draw an arrow from left to right for all those molecules passively reabsorbed into the l nf the nerituhular capillary. Use darker arrows for those that are normally reabsorbed completely by

Answer 1

1. Homeostasis means state of equilibrium inside the human body. Kidney help in maintaining the normal level of water, ions and other substances in the body of organism. The substances do not require by body are eliminated by kidney. Kidney too secrete a hormone called as erthyropoietin that is responsible for maintaining normal rbc number in the body.

2. If the cells does lost all the nutrients by the body, there will be a ionic imbalance in the body that could lead to diseaase condition known as diabetes insipidus.

3. Urea is least reabsorbed in the kidney. This is required to maintain homeostasis because it helps in the building of high osmotic gradient in the renal medulla of kidney, that in turn essential for maintaining the optimal level of renal urine.