1.5: Renal Histology Flashcards
What are three functions of the kidney?
- Maintain water and electrolyte homeostasis
- Excrete toxic metabolic waste products
- Act as an endocrine gland - secrets renin and erythropoietin
Describe the renal capsule?
Thin but strong capsule of dense collagen fibres
Describe the renal hilum?
This is the site of entry for the renal artery and the site of exit of the renal vein and ureter
Label these parts of the kidney? (A–>F)
A = Cortex
B = Capsule
C = Calyx
D = Renal Pelvis
E = Renal Papilla
F = Medullary Pyramid
What is the smallest functional unit of the kidney?
A Nephron
What are nephrons composed of?
They are composed of a renal corpuscle and renal tubules
Renal Corpuscle = Red Circle
Nephron = Blue Circle
What is the function of the renal corpuscle?
This filters
What is the function of the renal tubules?
These modify the urinary filtrate (reabsorption of nutrients, electryoltes etc.)
Approxiametly how many nephrons are in each kidney?
About 1 million
Where is the medullary papilla?
At the end of the collecting duct
Urine drips off the medullary papilla into the minor calyx
What is the renal corpuscle?
This is composed of a knot/tuft of capillaries that forms the glomerulus
Sits inside a capsule = Bowmans capsule
It separates blood from the urinary filtrate
What supplies and drains the renal corpuscle?
Supplied by afferent arteriole
Drained by efferent arteriole
Describe the cells of Bowman’s capsule?
Stratified Squamous Epithelium
Describe what separates the blood and the urinary filtrate?
Two layers of cells
Endothelium and Epithelium
Epithelium contains podocytes
Thick basil lamina between the layers of cells
Describe the podocytes?
These are cells found in the epithelium of the renal corpuscle
They have finger like projections that interdigitate to form filtration slits
Describe how the urinary filtrate moves from the blood into Bowman’s space?
Passes through basement membrane
Passes through epithelium
Passes through filtration slits formed by podocytes
Into bowmans space
What is the main filtering element in the renal corpuscle?
The thickened basal lamina
The volume of filtrate produced greatly exceeds the volume of urine excreted by the body. Why?
A large volume of the filtrate is reabsorbed and isn’t excreted in the urine