Selective Reabsoption

What are the adaptations of epithelial cells in the PCT?

Microvilli basal infoldings numerous mitochondria and co-transporter proteins

What is the function of microvilli in the PCT?

They increase surface area for reabsorption

What is the function of basal infoldings in the PCT?

They increase surface area for moving substances into blood capillaries

Why are there numerous mitochondria in PCT epithelial cells?

They provide ATP for active transport

What is the function of co-transporter proteins in the PCT?

They allow co-transport of substances from filtrate into epithelial cells

Which substances are reabsorbed in the PCT?

Glucose amino acids chloride ions sodium ions and water

How much water is reabsorbed in the PCT?

About 85%

What happens to sodium ions in the PCT?

They are actively transported into blood capillaries

How does active transport of sodium ions affect sodium concentration in PCT epithelial cells?

It reduces the sodium ion concentration

How does sodium ion re-enter PCT epithelial cells?

It moves down its concentration gradient from the PCT lumen

Which substances are co-transported with sodium ions?

Glucose and amino acids

How do reabsorbed molecules enter the blood capillaries?

They diffuse into the blood capillaries

What is the main function of the DCT?

To make final adjustments to the filtrates content

What substances are mainly reabsorbed in the DCT?

Water and salts

How are remaining useful substances reabsorbed in the DCT?

Primarily through active transport

How does the DCT regulate water and solute reabsorption?

By altering membrane permeability

How does the DCT help regulate blood pH?

By selectively reabsorbing certain ions

Which adaptations does the DCT have for reabsorption?

Microvilli and mitochondria

How can hormones affect the DCT?

They influence adjustments to the filtrate composition