ARCH-B-10: Renal Vessels, Nephron Ultrafiltration, Selective PCT Reabsorption & ADH Osmoregulation

Trace each solute through the nephron:
- Plasma proteins: $M_r > 68{,}000$; blocked by the glomerular basement membrane $\implies (-)$ in filtrate and $(-)$ in urine.
- Glucose: small molecule ($M_r = 180$); filtered freely into Bowman's capsule $(+)$, then **$100\%$ selectively reabsorbed in the PCT** $\implies (-)$ in final urine.
- Urea: small molecule; filtered freely $(+)$ and concentrated as water is reabsorbed $\implies (+)$ in final urine.