4.4_1 Renal I Part II Flashcards
In a normal capillary bed, _____ is high pushing out
HP
OP
In a peritubular capillary, _____ is very low
HP
What does the low HP in peritubular capillaries yield?
Net reabsorption of water
OP is a stronger force in peritubular capillaries because of..
Proteins
~_____ % of filtrate is immediately captured from the filtrate
65
~___% of Na+ ion reabsorption occurs in the proximal tubule via __________ using the ________
65
Primary active transport
Na+ / K+ ATPase
Most other ions (Cl-, K+, Ca2+, Mg2+, Pi) are absorbed from the proximal tubule via _______ or _______
Facilitated diffusion
Secondary active transport
Glucose and amino acids are reabsorbed by ….
Carrier mediated secondary active transport with Na+ ions
Na+ transport across luminal or apical membrane is ______
Passive (facilitated diffusion)
Na+ transport across the basolateral membrane is…
Active (ATPase pump) creates a low intracellular [Na]
The luminal membrane is closer to / touching the…
Tubular fluid
The basolateral membrane is closer to / touching…
Interstitial fluid
Glucose and amino acids are transported by what process across the luminal membrane?
Secondary active transport (supporter proteins, use Na+ gradient)
Glucose and amino acids cross the basolateral membrane via..
Facilitated diffusion
Maximum tubular transport
Carrier proteins like the Na / Glucose supporter can saturate if the maximum transport capacity (tubular maximum) is exceeded
Tubular maximum for glucose
320 mg / min
Tubular secretion is for..
Larger, unwanted molecules
Tubular secretion is going from the ____ to the ______
Blood
Filtrate
Tubular secretion is he..
Active transfer fo materials from peritubular capillaries to lumen of both the PCT and DCT (filtrate)
Two generic carrier systems for tubular secretion
Basic carriers
Acidic carriers
Basic carriers
For basic molecules
ex: dopamine, histamine
Acidic carriers
For acidic molecules
ex: uric acid, sulfate conjugates, penicillin
Tubule cells can modify molecules to make them more…
Water soluble and biochemically “inert”
Sulfation
Steroid hormones get conjugated with SO2- (sulfates)
Many hydrophobic molecules also leave the body through…
Liver bile
Cytochrome enzymes
In tubule cells, work to detoxify xenobiotic compound (ex: antibiotic drugs
Nephrotoxic
Presence of some drugs kills tubule cells
Examples of nephrotoxic drugs
Amphotericin B (anti fungal) Cisplatin (Chemo)
