A capillary network around the renal tubule is formed by:
| 1. | Afferent arteriole | 2. | Efferent arteriole |
| 3. | Vasa recta | 4. | Arcuate artery |
| I: | extends from the cortex of the kidney to the inner parts of the medulla. |
| II: | can reabsorb water to produce a concentrated urine. |
| III: | allows passage of small amounts of urea into the medullary interstitium to keep up the osmolarity. |
| IV: | plays a role in the maintenance of pH and ionic balance of blood by the selective secretion of H+ and K+ ions. |
Consider the given two statements:
| Statement I: | Urea is used as an osmolyte in the human body. |
| Statement II: | Urea is produced in the human liver. |
1. Only Statement I is correct.
2. Only Statement II is correct.
3. Both Statement I and Statement II are correct.
4. Both Statement I and Statement II are incorrect.
All of the following regarding juxtamedullary nephrons in human kidneys are correct, except:
| 1. | the entire nephron is located in the superficial cortex of the kidney |
| 2. | the renal corpuscle comprises a glomerulus and a glomerular capsule |
| 3. | blood arrives at the glomerular capillaries via an afferent arteriole |
| 4. | the proximal convoluted tubule leads into a long nephron loop |
| 1. | An excessive loss of fluid from the body can activate the osmoreceptors which stimulate the hypothalamus to release antidiuretic hormone (ADH) or vasopressin from the neurohypophysis. |
| 2. | An increase in body fluid volume can switch off the osmoreceptors and suppress the ADH release. |
| 3. | ADH can also affect the kidney function by its dilatory effects on blood vessels. |
| 4. | An increase in blood pressure can increase the glomerular blood flow and thereby the GFR. |