Histology Flashcards
what 2 things is the nephron composed of?
renal corpuscle and renal tubules
what is the renal corpuscle?
tuft if capillaries called the glomerulus and the bowmans capsule
what is the bowmans capsule lined with?
simple squamous epithelium
what is the glomerulus supplied and drained by?
supplied by an afferent arteriole and drained by an efferent arteriole
what are the 2 cell layers that separate the blood from the glomerular filtrate?
the capillary endothelium and a specialised epithelium which lies on top of the glomerular capillaries- called podocytes
what is an identifying feature of podocytes?
have interdigitating cell processes forming filtation slits
what is between the 2 cell layers separating the blood from the glomerular filtrate?
a thicker than usual basal lamina
what is the thick basal lamina made up of?
GAGs.
what do the scattered mesangial cells produce?
a connective tissue core called the mesangium
what are the functions of the mesangial cells?
support and removal of debris
what is a major histologically feature of the proximal convoluted tubule?
has a substantial brush border
what is the appearance of the cells in the proximal convoluted tubule?
cuboidal epithelial cells with central nucleus. lots of mitochondria
in the medulla, what is the thin limb of loop of Henle lined with?
thin, simple squamous lining
in the thin limb of loop of Henle, where is the nucleus?
typically protrudes into the lumen
what is the thick ascending limb of loop of Henle lined by?
simple cuboidal epithelial cells
what is abundant in the thick ascending limb of loop of Henle?
mitonchondria
the collecting ducts and the thick ascending limb are both lined by simple cuboidal epithelium, how can you tell them apart?
collecting ducts do not stain intensely whereas the thick ascending limb does as they are very active with their abundant mitochondria
what are the vaso recta blood vessels?
A specific form of vasculature serving the medulla
where are the distal convuluted tubules found?
in the cortex
what are the DCT lined by?
simple cudoidal epithelium
what does the DCT lack that the PCT has?
DCT lack a brush border and extensive microvilli.
what gives rise to the medullary rays?
in the cortex, the collecting ducts, along with the straight segments of the proximal and distal tubules are gathered together in parrallel bundles running perpendicular to the surface of the kidney
what is the lining of the collecting ducts?
simple columnar epithelium
what are the ducts of bellini?
the section of the collecting duct thst converges on, and opens at the renal papilla into minor calyx
where is the juxtaglomerular apparatus formed?
at the site where the DCT passes adjacent to the vascular pole of the same renal corpuscle that is part of that nephron.
what are the 3 components of the juxtaglomerular apparatus?
- the macula densa
- the juxtaglomerular cells
- the extraglomerular mesangial cells (or lacis cells)
at which side are the cells in the macula densa taller?
on the side where the DCT is nearest to the afferent arteriole
what does the macula densa function to do?
sense ion composition in the DCT
what are the juxtaglomerular cells and what do they contain and release?
modified smooth muscle cells in wall of the afferent arteriole, these cells contain/secrete renin.
where do the extraglomerular mesangial cells extend to?
outside of the renal corpuscle
what is almost all of the conducting parts of the urinary tract lined in?
transitional epithelium or urothelium
describe urothelium?
stratified and 3-6 cell layers
what are the cells called in the luminal surface of the conducting parts of the urinary tract?
umbrella cells
what is the membrane of the umbrella cells facing the lumen like?
thickened and inflexible
what 2 facts explain the special structure of the epithelium of the umbrella cells?
- the variability in thickness of cells represents different states of distention
- the apical surface of the cells at the surface have a thickened membrane to provide a highly impermeable barrier
what is below the epithelium of the urothelium?
a lamina propria and 2-3 layers of smooth muscle
what happens to the smooth muscle in the ureter as you get closer to the bladder?
it gets thicker
what is the female urethra lined by?
initially by transitional epithelium but transitions to stratified squamous near its termination.
what is the prostatic urethra (in males) lined by?
transitional epithelium
where does the membranous urethra extend from?
the prostate to the bulb of the penis
how long is the membranous urethra?
approx 1cm
what lines the membranous urethra?
stratified columnar epithelium
how long is the penile urethra?
approx 15cm
what is the penile urethra lined by?
lined by stratified columnar epithelium which becomes stratified sqaumous epithelium near the tip of the penis
what type of glands are in the prostate?
tubulo-alveolar glands
what is the prostate lined in?
simple columnar secretory epithelium and with a fibromuscular stroma
what percentage if seminal fluid volume is made up by the prostate secretions?
about half
