Intro Flashcards
Complications from what 2 diseases commonly involve kidney dysfunction?
DM and CHF
The function of the kidney is to “maintain homeostasis”. What, exactly is it trying to regulate?
Trying to maintain
1) Sodium (140)
2) Potassium (4)
3) pH (7.4)
Where is the nephron located?
in the medullary pyramid of the kidney
After leaving the proximal convoluted tubule, where would I go next?
The strait proximal tubule (my point is, be able to draw the nephron)
Where are the macula densa cells?
They are in the distal convoluted tubule which is in contact (next to) the afferent arteriole
What do the macula densa cells do?
Sense the net amount of NaCl. If sodium concentration falls, it will
1) signal the JG cells
2) Vasodilate the afferent arteriole (increase GFR)
What do the JG cells do when stimulated?
They make and secrete renin
Besides getting a signal from the macula densa cells, what else triggers the release of renin from the JG cells?
stretch receptors detect drop in BP
Review: What is the order of the RAAS?
drop in BP–>renin release. Renin converts Angiotensinogen to AT1. ACE converts AT1 to AT2. AT2 vasoconstricts and releases aldosterone. sweeet
What happens in the kidneys in response to low concentrations of Na+?
Increased renin and increased GFR
MD cells shrink signaling JG cells/renin and signaling afferent arterial dilation
Within the glomerulus, the capillaries are arranged into lobular structures called _____________________
glomerular tufts
REVIEW: Capillaries are made up of ________ layer(s) of ______________ cells
one, endothelial
The capillary walls are fenestrated. Why?
the “windows” allow plasma to diffuse through, but retain formed elements like RBCs or proteins
What are the responsibilities of the fenestrated endothelial cells?
regulate coagulation, inflammation, vasomotor tone, make antigens, release NO.
(Capillaries: NOT CIA)
This layer is an important determinant of the glomerular protein filtration barrier.
Glomerular Basement Membrane (GBM)
What IS the GBM?
a gel made of glycoproteins and type IV collagen
What does the GBM do?
it’s part of the filtration system.
(The GBM helps to perform the filtration function of the glomerulus, separating the blood in the capillaries from the filtrate that forms in Bowman’s capsule)
What does a healthy basement membrane look like?
Thin and lacey
What happens when there’s damage to the GBM?
Sucks at filtering. Either it starts loosing important things in the urine like protein or RBC’s, or it becomes too thick and the GFR is decreased