Flashcards in Histology Deck (42):
How does the kidney act as an endocrine gland?
What is the kidney covered by?
Thin, strong, collagen capsule
What is the medulla divided into and what direction do they point in?
- Apices point to hilum (papillae)
What is each nephron composed of?
What is the approximate length of each nephron?
What is the renal corpuscle formed from?
What epithelium makes up the Bowman's capsule?
How many cell layers separate the blood and glomerular filtrate? What are these layers?
- Capillary endothelium
- Specialised epithelium on top of capillaries:
What do the podocytes form?
Filtration slits (~25nm wide)
What lies between the cell layers separating the blood and glomerular filtrate?
Thicker basal lamina (0.3μm instead of 0.05μm):
- Made of Glycosaminoglycan (GAGs)
What forms the mesangium and what does it do?
Functions as connective tissue core:
- Removes debris
Where does the Loop of Henle lie?
In the renal medulla
What is the structure of the cells lining the thin descending limb of the Loop of Henle?
Nuclei protrude into lumen
What is the structure of the cells lining the thick ascending limb of the Loop of Henle?
Where is the distal convoluted tubule found?
What lines the distal convoluted tubule?
Simple cuboidal epithelium
What does the DCT lack that the PCT has?
A brush border
Where do the collecting ducts run alongside?
Straight segments of PCT and DCT in cortex
Coupled with the structures collecting ducts run alongside, what is the name for these bundles?
- Parallel bundles
What direction do the medullary rays run?
Perpendicular to kidney surface
In the medulla, what do the collecting ducts run alongside?
Loops of Henle
What epithelium lines the collecting ducts?
Where do the juxtaglomerula apparatuses form?
At site where DCT passes:
- Adjacent to vascular pole of same renal corpuscle
What are the three components of the juxtaglomerular apparatus?
Extraglomerular mesangial cells/Lacis cells
Where does the macula densa lie?
On side of DCT closest to afferent arteriole
What are the features of the DCT cells?
Intensely stained nuclei
What do macula densa do?
Sense DCT ion composition
What are the juxtaglomerular cells and what do they do?
Modified smooth muscle in afferent arteriole wall
Contain and secrete renin
What are the extraglomerular mesangial cells?
Modified mesangial cells that extend out of the corpuscle
What type of the epithelium is the urothelium?
Transitional stratified epithelium (3-6 cells)
What are the cells at the luminal surface of the urothelium?
Umbrella cells (domed):
- Special thickened and inflexible membrane
Why does the urothelium have a special structure?
- Different states of distension
Apical surface of cells have a thickened membrane:
What lies below the urothelium and what is it?
- 2-3 layers of smooth muscle
How long is the urethra in women?
What epithelium is the female urethra?
Transitional and then stratified squamous
How long is the urethra in men?
How long is the prostatic urethra and what lines it?
How long is the membranous urethra, where does it like and what lines it?
- From prostate to bulb of penis
Transitional -> Stratified columnar epithelium
How long is the penile urethra and what lines it?
Stratified columnar (stratified squamous at tip of penis)
What glands form the prostate gland?
What type of epithelium are the tubules in the prostate gland lined with?
Simple columnar secretory epithelium with fibromuscular stroma