To review:
Whether the percentage of long loops of Henle or relative medullary thickness (RMT) is a better predictor of an animal’s ability for producing concentrated urine.
Given:
The percentage of long loops of Henle, RMT, and freezing point depression (FPD) for various mammals is given in the Table 1:
Table 1: Percent long loops of Henle, RMT, and FPD for different mammals.
Introduction:
RMT is defined as the thickness of medulla divided by volume of kidney. It is a measure used to normalize the relative length of loops of Henle as compared to kidney size for differently sized mammals. The medulla has long and short loops of Henle. The long loops of Henle are the ones that extend the whole length of the kidney, while the short ones do not.
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EBK LIFE: THE SCIENCE OF BIOLOGY
- Which of the following does not contribute to the high salt concentration in the interstitial fluid of the kidney medulla? (a) active transport of sodium from the upper part of the ascending limb (b) diffusion of salt from the ascending limb of the loop of Henle (c) reabsorption of salt from various regions of Bowmans capsule (d) counterflow of fluid through the two limbs of the loop of Henle (e) diffusion of urea out of the collecting ductarrow_forwardWhich of the following statements concerning the medullary verticle osmotic gradient is TRUE: W. The loops of Henle of juxtamedullary nephrons establish a medullary osmotic gradient by means of countercurrent multiplicationX. The vasa recta enable the medulla to be supplied with blood while conserving the medullary osmotic gradient Y. The medullary osmotic gradient permits excretion of urine of differing concentrationsZ. The collecting tubules of all nephrons descend through the medullary osmotic gradient before emptying into the renal pelvis Select one: a. if only W, X and Y are correct b. if only W and Y are correct c. if only X and Z are correct d. if only Z is correct e. if all are correctarrow_forwardThe osmotic concentration of seawater is approximately 1,000 mOsmol L-¹. Which of the following marine vertebrates can drink seawater without becoming dehydrated? A. A bony fish such as the flounder (maximum urine osmolarity = 340 mOsmol L-¹) B. A marine bird such as an albatross (maximum urine osmolarity ≈ 640 mOsmol L-¹) C. A marine reptile such as a loggerhead turtle (maximum urine osmolarity ≈ 320 mOsmol L-¹) D. A marine mammal such as a whale (maximum urine osmolarity ≈ 1,920 mOsmol L-¹) E. All of the abovearrow_forward
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- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning