urinary system question.

[ecsezandohs]

"filtration of th blood occurs in three main steps explain each of these steps, identify the structures involved and describe the movement of materials in and out of the nephron. "

is a question for my next biology test. i know this:

the glomerous is a knot of capillares that filters out small molecules from the blood. it gets out most of them.
the proximal convoluted tubule is where reabsorption of filtrate components occur. the loop of henle (or nephron) consists of a descending limb that allows water to leave and an ascending limb that extrudes salt. there is also a distal convoluted tubule tht recieves molecules secreted from the blood into to the tubule.

is there anyother way to explain that??? maybe in an easer way. do i have the steps right? does it make sense?? thanks!!!

[mith]

The important thing about the glomerules is that it keeps in the blood cells.

[Darby]

Step one: everything small enough to go through the filter holes (except a lot of the water, stuck to the larger particles) is filtered out.

Step two: particles that left but which the body needs (sugar, minerals, etc) get reabsorbed.

Step three: waste that wouldn't fit through the filter is excreted, much of the water is taken back.