Renal Physiology (5A) Flashcards
Sources of water gain includes
Ingested liquid
Water from oxidation of food
Water loss (output) occurs through
Skin, respiratory airways (insensible water loss meaning that we don’t notice it)
Sweat
GI tact, urinary tract, menstruation
Water will move via ___ across water channels known as —-.
diffusion, aquaporins
Where is a large volume of water reabsorbed?
PCT
Are aquaporins always open or closed in the proximal tubule cells?
they are always open
IMPORTANT: what is water reabsorption dependent upon?
- Na+ reabsorption
- Osmotic gradient set up by the Na+ that serves as a driving force
Cells lining the cortical (CCD) and medullary collecting duct (MCD) are under —- control.
Physiological
Which hormone regulates water reabsorption?
Vasopressin or anti diuretic hormone (ADH)
What does ADH regulate?
a specific type of aquaporin
Where does this regulation take place?
In the cells of the collecting ducts
In the proximal tubule, the mechanism of water reabsorption is ___ and occurs through aquaporin _.
passive, 1
In the Loop of Henle, the mechanism of water reabsorption occurs at the ___ thin limb and is passive occuring at aquaporin _.
descending, 1
At the distal tubules, there is __ water reabsorption.**
no
At the large distal tubule and collecting ducts, the mechanism of water reabsorption is __ and occurs via aquaporins __, __, ___.
passive, 234
At the PCT, Loop of Henle and the DT are there hormones required to regulate water permeability?
no
At ___ the large distal tubule and collecting duct, ____ is required to regulate water permeability.
only, ADH
Most of the reabsorption occurs at the __ and none occurs at the ___.
PCT, DT
In the PCT, the Na+ will first move from the lumen into the epithelial cells to cause ___ osmolarity in the lumen. This causes H20 to ____ across the membrane and that is because there is ___ osmolarity in the interstitial fluid.
low, diffuse, high
Order includes: lumen –> epithelial cells –> interstitial fluid and ____.
peritubular capillaries
Water reabsorption occurs at the ____ descending Loop of Henle.
thin
Salt reabsorption occurs at the ___ ascending Loop of Henle
thick
The ascending limb is ___ to water.
impermeable
There is a countercurrent ___ in the Loop of Henle that is involved in water reabsorption.
multiplication
**The loop of Henle is a single tubule that has two sides that are closely ____. The fluid will stream in ___ directions and there are ____ transport capabilities on each side of the tubule.
juxtaposed, opposite, different
