| Thin ascending limb of loop of Henle | |
|---|---|
| Scheme of renal tubule and its vascular supply. (Labeled at center left.) | |
| Nephron ion flow diagram | |
| Gray's | subject #253 1223 |
The thin ascending limb of loop of Henle is a sub-portion of the loop of Henle in the juxtamedullary nephron of the kidney. The thin ascending limb is impermeable to water, and is also permeable to ions in particular Na and Cl. As filtrate passes up through this limb, the solute concentration of the surrounding medulla decreases because more water is leaking into surrounding plasma, and increases the solute concentration within the loop of Henle. However, because this segment is also permeable to solutes, ions and other small particles can pass through the limb and enter the extracellular fluid (ECF) which causes the solute concentration of the ECF to rise, and thus causes the solute concentration within the loop of Henle to decrease. How the mechanism of the ascending loop of Henle decides how much water and/or solutes to reabsorb depends on the state of the body at the time. These molecules will flow down their concentration gradient. For example, if the body is dehydrated, more water will flow out of the loop of Henle and be reabsorbed back into the blood. (Information from Marieb, E. N. 2010. Human Anatomy and Physiology, 8th Ed. Pearson Benjamin Cummings.)
As in the descending limb, the epithelium is simple squamous epithelium.
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.
|
||||||||||||||||||||||||||||||||||||||||