Histo Flashcards
Briefly outline the embryological development of the urinary system
Identify and describe the histological features and, in general terms, the physiological functions of the nephron, and its various components.
The nephrons come in a few key types with two being most prominent, Cortical, and juxtamedullary nephrons. With the cortical having a short loop of henly that barely extends into the medulla, while the JM nephrons dive way down into the medulla It’s basic functions are to filter, reabsorb, and secrete
bowman’s capsule (visceral and parietal layers)
The capsule is at persistently lower pressure than the arteriolar, allowing pressure to filter material into the capsule The visceral layers are podocytes, they are hard to differentiate at the level of magnification the shows the entire glomerulus. The parietal layers are simple squamous.
glomerular capillaries
Receive flow from the afferent arteriolar and pass them through the glomerulus. The capillaries are FENESTRATED and interact with the podocytes Lamina rare externa Lamina densa Lamina rara interna
afferent and/or efferent arterioles
Deliver flow to the glomeruli As the efferent system leaves it forms an arteriolar portal system.
juxtaglomerular apparatus
macula densa
They monitor sodium and chloride levels levels moving into the collecting ducts. This little buggier is a source of hypertension, reading the overall blood pressure as low courses renin release, angiotensin increase and resorption of Appear as a dense packing of cells right at the end of the tubules. Close to the mesangial cells and the smooth muscle. Together they form the
proximal convoluted tubule
Thick cuboidal cells with unclear boundaries on E and M stain. Has a well developed brush border on the luminal border.
descending thick limb (proximal straight tubule)
Cuboidal in shape, transition to the loop of henly
descending thin limb,
Cells are now simple squamous
ascending thin limb
ascending thick limb (distal straight tubule
distal convoluted tubule,
Nuclei are at the Apex, Brush border is virtually gone
collecting tubule
As we progress through the collecting system the cells are more easily distinguished from one another. The lumen grows.
Diagram the flow of blood from the aorta, through the renal arteries, interlobar arteries, arcuate arteries, interlobular arteries, afferent arteioles, glomeruli, efferent arterioles to peritubular capillaries.
Mesangial cell
Cells that move withing the glomerular basement space and act as macrophages, destroying larger items that get filtered out of the blood. The have an almost brain like appearance on EM view. Can be intra and extra glomerular, They provide some contractile force.
