Tubular function Flashcards
What are the two parts to the proximal tubule?
First 60% is the proximal convoluted tubule
The remainder is the proximal straight tubule
What is present on the apical surface of proximal tubule cells?
Microvilli
forming a brush border
Through which pathways do ions move in the proximal convoluted tubule?
Paracellular
Transcellular
How much water has been reabsorbed by the end of the proximal convoluted tubule?
70%
What ion moves in the proximal convoluted tubule?
Na+ down its electrochemical gradient
NaKATPase on basolateral membrane to maintain gradient
What moves into proximal convoluted tubules as a result of Na+ movement?
Glucose
Amino acids
How does water move transcellularly in the proximal convoluted tubule?
Aquaporin 1 (AQP 1)
Why does water move paracellularly in the proximal convoluted tubule?
Hydrostatic and osmotic force
Is inulin absorbed in the proximal tubule?
No
Is urea absorbed in the proximal tubule?
Weakly
Is chloride absorbed in the proximal tubule?
Weakly
Is Na+, K+ absorbed in the proximal tubule?
Yes
Is HCO3- absorbed in the proximal tubule?
Yes
Are amino acids absorbed in the proximal tubule?
Strongly
Is glucose absorbed in the proximal tubule?
Strongly