Week 9 Kidney Physiology tut

Reabsorption and where it occurs in the nephron.

Movement of ions and solute (followed by water) from nephron into the blood.

Happens in the proximal convoluted tubule, loop of Henle (descending limb water reabsorption, ascending limb Na+ reabsorbed) , distal convoluted tubule (mainly ions) and collecting duct

What do we use to indicate kidney function?

Using creatine as a marker…? (PANOPTO)

When measuring kidney function what properties should the marker have?

• physiologically inert

• small

• cant be reabsorbed

• freely filtered in the glomerulus

• Filtered S= Excreted S in the urine

Tubuloglomerular feedback.

The ascending limb attached to the afferent and efferent arteriole, in the middle macula densa detects a change in the diameter of the ascending limb. When squeezed paracrine signal is released, vasoconstriction of afferent arteriole so less volume of blood enters, GFR decreases.

What structural adaptations are seen in cells of the PCT?

• High SA: many microvilli on the apical surface

• Many mitochondria for active transport (reabsorption)

What types of transport (of solutes) occur in the nephron?

In general: Osmosis and diffusion, in PCT glucose reabsorption (co-transport, symporters which is in different directions), Antiporters (same direction)