Here is a normal glomerulus. It sits in loops of proximal and distal tubules, and at 6 o'clock it comes into close contact with its own distal tubule at the macula densa.
The title of this talk mentions "glomerulonephritis", literally inflammation of glomeruli, but it should really be "glomerulopathy", as it is going to include non-inflammatory diseases, or barely inflammatory diseases, because the consequences are the same.
The glomerulus sits at the end of a nephron, and in each kidney approximately 1 million of these contribute to the daily glomerular filtrate of about 150 litres, that's 30 Imperial gallons (40 US gallons) and double your weight, or a good bathful. [Beth’s pic here]
The tubules reabsorb 99% of this, so quite small alterations in the proportion of, say, sodium or water that is reabsorbed will quickly affect overall balance.
Creatinine and size - rather oddly
[Improve this fig and add more about GFR?]
But the most informative figure for overall renal function is the glomerular filtration rate, GFR, which should be about 100 mls/minute in an average sized person.
See how there is a lot of white space in this normal glomerulus. In life these are capillary loops, which are filled with blood. The glomerular basement membrane, or GBM around these loops should look sharp - "as if you could cut your finger with on them".
Cells of the glomerulus
In this diagram you can see how podocytes sit outside these capillary loops, holding them open and synthesizing most of the GBM. We'll look at them more closely shortly.
Inside the loops, endothelial cells are smeared very thinly around with only the nuclei really visible.
A few mesangial cells sit in between the loops
The pink material in the middle, between the capillary loops, is mesangial matrix, synthesized by mesangial cells. You shouldn't see more than three mesangial cells together.
Podocytes can be seen at the edges. Endothelial cells - you can just see their nuclei.