9/25 - Countercurrent Systems

Descending

Water will diffuse out of which limb of the loop of Henle? This will create highly concentrated filtrate that will be used to make the medulla salty in the other limb.

Ascending

NaCl will be pumped out of which limb of the loop of Henle? This will create a very salty medulla environment used by the other limb to diffuse out water.

Na-K-2 chloride

What type of pump found in the ascending limb of the loop of Henle is used to pump NaCl into the medulla as the loop itself is impermeable? It uses ATP as a form of active transport.

Bottom

Will the Na-K-2Cl pumps be more active at the top or bottom of the loop of Henle?

Countercurrent multiplier

The process by which Na-K-2Cl pumps remove salt from the ascending limb to make the medulla salty, which then allows water to diffuse out of the descending limb forming concentrated filtrate with more salt that will be pumped out is referred to as what cycle?

Vasa recta

What is the term for the peritubular capillaries which follow the loop of Henle exactly and have blood flowing in opposite direction to the flow of filtrate? They allow the countercurrent exchanger mechanism to work.

Countercurrent exchanger

What is the term for the mechanism/process by which the vasa recta blood flows opposite to the flow of filtrate in the nephron tubule allowing salt to be taken in at the ascending tubule and released at the descending tubule, and water to be released at the ascending tubule and taken up at the descending tubule?

Diluted

Stopping facultative water reabsorption, reducing ADH release, making the distal tubule and collecting duct impermeable to water, and increased urine volume will produce what type of urine?

Concentrated

Increased facultative reabsorption, release of ADH, and maintenance of the countercurrent mechanism/hypertonic medulla will produce what type of urine?

Osmosis

What type of transport removes water from the collecting duct in facultative reabsorption?

ADH

What hormone controls the permeability of the collecting duct?

Vasopressin

What is another common name for ADH?

Aldosterone

What hormone is used to increase water reabsorption by increasing Na+ reabsorption? It causes increased Na+ channels and Na/K pumps by binding to steroid receptors in the epithelial cells?

ADH

What hormone is used to increase aquaporin-2s in the collecting duct and distal tubule by binding to the epithelial cell receptor?