15- Renal Phys (Kruse & Pierce) Flashcards
What is the basic unit of structure in the kidney?
Nephron
A ________ is used separate to water, ions and small molecules from the blood, filter out wastes and toxins, and facilitates the concentration of urine.
Nephron
Each nephron contains a tuft of glomerular capillaries called the _________.
Glomerulus
Glomerular capillaries are covered by epithelial cells and are encased in ________ ________. Large amounts of fluid are filtered from the blood here.
Bowman’s Capsule
Fluid filtered from the glomerular capillaries flows into Bowman’s Capsules and then into the ________ ________.
Proximal Tubule
What is actively reabsorbed in the Proximal Tubule (convoluted and straight)?
85% sodium bicarbonate (NaHCO3)
65% sodium chloride (NaCl)
65% potassium (K+)
100% glucose and amino acids
What is passively reabsorbed in the Proximal Tubule (convoluted and straight)?
Water
In the Proximal Tubule (convoluted and straight) uses the _________ to maintain low intracellular Na+ concentrations.
Na+/K+ ATPase
This is an enzyme in the Proximal Tubule that catalyzes the formation/dehydration of carbonic acid.
Carbonic Anhydrase
In the proximal tubule, acid and base secretory systems secrete drugs into the ________ from the blood (i.e., diuretics, NSAIDs, antibiotics).
Lumen
What is the Thin Descending Loop of Henle responsible for?
Water reabsorption
The (THICK/THIN) Ascending Loop of Henle is relatively impermeable to water, and other ions/solutes.
Thin
What are the main functions of the Thick Ascending Limb?
Impermeable to water
25% sodium reabsorption
Na+/K+/2Cl- Cotransporter (NKCC2)
Reabsorption of cations
In the Thick Ascending Limb, this is what establishes the ion concentration gradient in the interstitium.
NKCC2
***Na+/K+/2Cl- Cotransporter
In the Thick Ascending Limb, there is an increase in ______ concentration in the cells that causes back diffusion of ______ into the tubular lumen. This allows a lumen-positive electrical potential to drive reabsorption of cations (Mg2+, Ca2+) via the paracellular pathway.
K+
K+
Tubular fluid is (DILUTE/CONCENTRATED) in the descending limb and (DILUTE/CONCENTRATED) in the ascending limb.
Concentrated
Dilute
What are the main functions of the Distal Convoluted Tubule?
10% NaCl reabsorbed
Relatively impermeable to water
Na+/Cl- Cotransporter (NCC)
Ca2+ passively reabsorbed by Calcium channels
In the Distal Convoluted Tubule, this actively transports NaCl out of the lumen.
NCC
***Na+/Cl- Cotransporter
In the Distal Convoluted Tubule, Ca2+ is passively reabsorbed by Calcium channels. What is this regulated by?
PTH
In the Distal Convoluted Tubule, the result if tubular fluid is (DILUTE/CONCENTRATED).
Dilute
In the Collecting Tubule, this is responsible for 2-5% of Na+ reabsorption. It creates an electrical gradient that facilitates K+ secretion down the concentration gradient.
Epithelial Sodium Channel (ENaC)
This is the most important site of K+ secretion by the kidney.
Collecting Tubule
This is the site at which all diuretic-induced changes in K+ balance occur. More Na+ delivered here will induce more K+ secretion.
Collecting Tubule
In the Collecting Tubule, _______ _______ increase urine acidity.
Proton Pumps