Functional Histology Of The Kidneys Flashcards
What is the glomerulus?
A knot of capillaries
What are podocytes?
Filter formed by the specialised epithelial cells coating the capillaries
What are the three stages of blood filtration through a capillary wall?
- fenestration between capillary endothelial cell of glomerulus
- thick fused basement membranes of capillary endothelial cells and podocytes
- filtration slit membrane between podocyte foot processes
What type of epithelium is the loop of henle made up of?
Thin squamous
How can you tell the difference between the distal and proximal convoluted tubules under a microscope?
Distal cells are smaller and paler
What do juxtaglomerular cells contain?
Renin
When do the juxtaglomerular cells release more renin?
In response to lower [Na+]
What are the three types of cells in the juxtaglomerular apparatus?
Juxtaglomerular cells, Lacis cells and macula densa
What is the function of the macula densa cells?
Senses [Na+] in the DCT. Fluid also appears to signal to the juxtaglomerular cells
What is the transitional epithelium and where is it found?
Special stratified epithelium
Ureters and bladder
Why is the transitional epithelium specialised?
To be impermeable to urine
What does the transitional epithelium look like?
Like the stratified squamous epithelium, except the biggest cells are apical
What structures does the transitional epithelium have that makes it impermeable to urine?
Plaques of specialised urine resistant plasma membrane
What happens to the impermeable plaques when the bladder is contracted?
The rigid plaques invaginate, forming pits that allows the bladder volume to decrease
