Histology of the Kidney Flashcards
what is the name of the hormone that increases the production of red blood cells
erythopoietin
what is erythopoietin
a hormone that increases the production of red blood cells
where are nephrons found
at the junction between the cortex and the medulla of the kidney
give a summary of the renal corpuscle
- a spherical structure in the cortex of the kidney that is foudn at the beginning of each nephrons
- it has a bowmans capsule, glomerulus, and urinary poles
what is the bowmans capsule
a double layer epithelial capsule
describe the outer layer of bowmans capsule
the outer layer is flat simple squamous epithelium.
describe the inner layer of the bowmans capsule
made up of complex epithelial cells called podocytes, with large oval nuclei. they wrap around each of the capillaries and form narrow slits between the cells which filter blood to form the ultrafiltrate
what is the glomerulus
a tuft of capillaries that supplies blood that is filtered to become the fluid known as filtrate.
what allows the supply and draining of glomerular capillaries
the vascular pole
what do the urinary poles do
these are where the ultrafiltrate is drained from the capsular space into the proximal convoluted tubule
what is the function of the proximal convoluted tubule
reabsorbs the substances the body wants to keep, including organic nutrients, proteins and most of the water and electrolytes.
secretes anions and cations like hydrogen and ammonium into the lumen of the tubule for excretion
why can the proximal convuluted tubule only be seen in cross sections
due to its winding path through the cortex
describe the walls of the proximal convoluted tubules
simple cubioidal or columnar epithelial cells with long microvilli.
describe the cytoplasm of the proximal convuluted tubule
eosinophilic
what are the elements of the loops of henle
there is the proximal straight tubule, distal straight tubule, and the thin descending and ascending limb
describe the proximal straight tubule
beginning of the loops of henle. thick descending limb. simple cuboidal or columnar epithelium and long microvilli.
describe the thin descending and ascending limb
simple squamous epithelium that passively reabsorbs water.
describe the distal straight tubule
end of the loops of henle. thick ascending limb. starts in the medulla and ascends into the cortex. reabsorbs electrolytes. simple cuboidal epithelial cells. has unclear borders between the cells and noticeably lighter staining
what is the macula densa
this is the area at the junction between the thick ascending lumb and the distal convoluted tubule. it has tightly packed cells and faces the arterioles. the cells have taller bodies and prominent nuclei.
describe the distal convoluted tubule
has shorter microvilli and lighter staining compared to proximal convoluted tubules. it reabsorbs sodium and chloride to make urine hypotonic
what does the collecting duct do
this drains urine from the nephron into the minor calyx at the apex of a renal pyramid and can also regulate electrolyte and fluid balance.
what are mesangial cells
large cells with irregular, dark nuclei found in the glomerulus
has contractile properties to regulate the amount of blood flowing to the glomerular capillaries. it is also involved in immune defense and repair of the glomerulus
what do the walls of the collecting duct consist of
simple cuboidal or columnar epithelial cells with well defined borders. it is lightly stained as it is not very eosinophilic
how does the collecting duct regulate electrolyte and fluid balance
by reabsorbing water from the filtrate as needed as well as secreting or absorbing various electrolytes
what does the macula densa do
it can detect changes in the sodium chloride levels in the tubule to trigger an autoregulatory response to maintain normal blood pressure and volume
