If the concentration of glucose in the blood flowing through the
kidneys is within the normal range, then which of the following
statements is correct?
a. The nephron pumps glucose into the collecting duct.
b. The Bowman's capsule secrets glucose back into the blood.
c. No glucose passes from the glomerulus into Bowman's capsule.
d. Most glucose within the nephron tubule is reabsorbed by the
blood.
e. Most glucose that passes from blood into the nephron tubule
remains in the urine and is subsequently excreted.
To answer this question, we need to understand how glucose is processed by the kidneys. Here's an explanation on how to eliminate the incorrect options and arrive at the correct answer:
a. The nephron pumps glucose into the collecting duct.
The nephron is responsible for filtering blood and producing urine, but it does not actively pump glucose into the collecting duct. Glucose is primarily reabsorbed by the nephron, not secreted.
b. The Bowman's capsule secrets glucose back into the blood.
The Bowman's capsule is the initial part of the nephron where blood is filtered. Glucose is filtered from the blood into the Bowman's capsule, not secreted back into the blood.
c. No glucose passes from the glomerulus into Bowman's capsule.
This statement is incorrect. Glucose does pass from the glomerulus (the network of capillaries inside the Bowman's capsule) into the Bowman's capsule during the process of filtration.
d. Most glucose within the nephron tubule is reabsorbed by the blood.
This statement is correct. After filtration in the Bowman's capsule, most of the glucose that enters the nephron tubule is reabsorbed back into the blood before it reaches the collecting duct. This is an important process to prevent the loss of glucose in urine.
e. Most glucose that passes from blood into the nephron tubule remains in the urine and is subsequently excreted.
This statement is incorrect. As mentioned earlier, most of the filtered glucose is reabsorbed back into the blood. Therefore, most of the glucose does not remain in the urine and is not excreted.
Therefore, the correct statement is: d. Most glucose within the nephron tubule is reabsorbed by the blood.
The correct statement is:
d. Most glucose within the nephron tubule is reabsorbed by the blood.
The normal range of glucose in the blood is maintained by the kidneys through a process called reabsorption. Glucose is filtered from the blood at the glomerulus, then it enters the Bowman's capsule and flows through the nephron tubule. However, in a healthy individual, most of the glucose that enters the nephron tubule is reabsorbed back into the blood, thus preventing it from being excreted in the urine. This process helps to maintain stable blood glucose levels.