Basic Renal anatomy

Question 1

in which part of the nephron does the urine first start to increase in concentration?

Answer 1

Proximal CT

Question 2

which part of the nephron is freely permeable to water and why is this important?

Answer 2

thin descending loop of henle
- water and sodium chloride is reabsorbed into interstitial space dependent on the osmolarity of the interstitial fluid – regulated by the activity of Na/K ATPase pumps of the ascending loop

Question 3

explain the importance of the ascending loop of henle

Answer 3

many metabolically active Na/K ATPase pumps
– pumps Na from lumen of ascending loop into the interstitial space
– raises osmolarity outside the nephron which increases water leaving the think descending loop ​

Question 4

Explain the importance of the Distal CT

Answer 4

can detect changes in sodium content of the renal fluid
– this signals to the granule cells of the juxtaglomerular apparatus and will influence how much renin it releases (less sodium = _ and more sodium = _)
– renin will then stimulate the release of ADH (antidiuretic hormone) from posterior pituitary and also produce angiotensin II
– more angiotensin II = more induced vasoconstriction = higher blood pressure and volume​

ADH then - ​

Question 5

Explain the process of ultrafiltration through Bowman’s capsule and the role it plays in urine production.

Question 6

Discuss the function of the thin descending loop and the thick ascending loop in the concentration of urine.

Question 7

Explain the role of the juxtaglomerular apparatus in regulating sodium content and its impact on the release of renin and ADH.