Histology of the Kidney and Urinary Tract (Cirillo) Flashcards
What are the three functions of the kidney?
Excretory -removes drugs, toxins, metabolic products
Homeostatic- Regulates water and ion balance
Endocrine- monitors oxygen in the blood (erythropoietin) and blood pressure
What are the divisions of the kidney?
Outer layer is the cortex
Inner layer is the medulla
What is a lobe?
How many does a typical kidney have?
A lobe is a renal pyramid (medulla) and the surrounding cortex.
A kidney has 6-18 lobes.
Where is the renal papilla? What does it do and why is it important?
The renal papilla is the tip of the medulla. It is where the urine empties into the ureter.
It is extremely sensitive and nephrotoxins/dehydration typically work here to cause renal papillary necrosis.
Is the kidney a blood rich system or a blood poor system?
The kidney is a blood rich system; it filters total blood volume every 4-5 minutes.
What are the two divisions of the kidney blood flow? What parts of the vasculature are shared between these two systems?
Blood to be filtered and blood to nourish the kidney
The Renal, Lobar, and Interlobar arteries are common; afterwards, they split into the arcuate arteries and the afferent arterioles.
What happens to the blood that goes to the afferent arterioles?
What is unique about that?
afferent arterioles lead to the glomerulus and then some of the blood goes to the efferent arteriole while some goes to the vasa recta before rejoining the efferents.
This is a two capillary system.
What are the four components of the renal corpuscle?
Glomerulus
Visceral layer of renal capsule
Parietal layer of renal capsule
mesangium
Where are corpuscles found?
In the renal cortex
What is the design of the vascular pole of the glomerulus?
Larger afferent arteriole than efferent arteriole
macula densa adjacent to arterioles
What is between the visceral and parietal renal capsule layers? Why is it important?
The urinary space; this is where ultrafiltrate collects and moves to the tubules.
What does the visceral renal capsule look like histologically?
simple epithelium
pores
foot processes of podocytes
glycocalyx
What is nephrin?
a connective protein that attaches podocyte across filtration slits in the visceral renal capsule.
What does the mesangium do?
physical support
regulates blood flow
regenerates the glomerular basement membrane
How does the mesangium regulate blood flow?
smooth muscle cells can constrict blood vessels
ANP and ANGII receptors moderate endocrine release
what does the parietal layer of the renal capsule look like histologically?
simple squamous epithelium