Question

How does the pct proximal convoluted tubule of the nephron contribute in Homeostasis?

Answer 1

Homeostasis is maintaining a constant internal environment.In this case maintaining concentration of body fluids.
Entire Nephron is involved in homeostasis of body fluids.
PCT also has its role in maintaining the homeostasis of body fluids.
It regulates the Ph of the body fluids by secreting H+ ions in to the filtrate from body fluids in exchange of HCO3- ions if the body fluids are more acidic.Opposite happens when the body fluids are more basic.
This is how PCT brings homeostasis of body fluids.