Renal Flashcards
what is the endocrine function of kidney?
production of EPO==> RBC production.
Also renin production for RAAS system.
what type of membrane covers the kidney?
serosa
what is the path of filteration from kidney?
nephron==>collecting duct==>minor calyx==>major calyx==>renal pelvis=>ureter=>bladder=>urethra.
why does the parallelism of medullary rays matter?
important for osmotic-oncotic pressure gradient.
how big is a renal corpuscle ?
200 um
what is within the papilla from cortex to inner medulla?
cortex contains renal corpuscle and convulated tubules and collecting duct, then outer and inner medulla has medullary rays
what does a renal corpuscle consist of ?
glomerulus, bowman’s capsule, urinary space
how many layers does bowman’s capsule have and what are their epithelia?
2: parietal layer: simple squamous
visceral layer: podocyte cells which are epithelial derived
what are podocytes for?
filteration apparatus of kidney
what are mesangial cells and where are their located and what do they secrete?
contractile cells which affect blood flow, also phagocytic cells that clear away debris. Located between capillaries and podocytes. Secrete ECM
is mesangial cell part of the filteration apparatus?
no
what type of epi has proximal, distal convoluted tubules and medullary rays have?
P and D conv: simple cuboidal
medullary rays: also simple cuboidal, collecting ducts can be simple columnar
what is initial and major site of reabsorption?
proximal convoluted tubule
what are the special modifications of proximal convoluted tubules?
microville, junctional complex on lateral surface, plicae/folds on lateral surface, basal striations, numerous mitochondria in basal region.
what are special modifications of DCT?
very short and few microvilli, junctional complex, plicae, basal striations, numerous mito
what makes up the filtration apparatus?
glomerular capillaries, glomerular BM, visceral layer of bowman’s cap, slit diaphragm
what are the characteristics of glomerular capillaries and BM?
capillaries are fenestrated 90nm diameter, lack diaphragm. BM is 35nm much thinker than normal
what does the visceral layer of bowman’s cap contain?
pedicles of podocytes around capillaries
what is excluded from the ultrafikterate?
plasma molecules more than 4nm, 70kDa mass and negative charged.
what can pass the filtration apparatus?
high hydrostatic pressure forces small molecules like water, glucose,AA, urea and ions through. ALL passive transport
what is juxtaglomerular apparatus?
next to glomerulus:
- macula densa
- juxtaglomerular cells and 3. extraglomerular mesangial cells
what is the function of juxtaglomerular apparatus?
regulate blood volume and composition via renin-angiotensin-aldosterone system/RAAS==>regulates BP
what series of events lead to increase BP through juxtaglomerular apparatus effects?
- low Na in DCT==>macula densa paracrine effect on juxta cells to release renin into blood==>increased BP.
- fall in BP in afferent arteriole==> baroreceptors in arterioles stimulates symp activity to act on the heart via beta 1 receptors which also leads to renin production from juxta cells to increase bp.
where are macula densa cells located at and what do they release?
located in the wall of DCT, they’re tall cells that release prostaglandins in response to low sodium which has a paracrine effect on juxta cells.
where are juxta cells, what’s their origin and function?
in arteriole walls, modified SM cells and release renin into blood in response to macula densa cells.
where are extraglomerular mesangial cells and what are their functions?
outside glomerulus and near arteriole, pale staining, secretion of proteins which stimulate RBC production and angiogenesis.
what type of epi is bladder? and describe their appearance
transitional epi, from apical to basal==> dome shaped cells (can be binuclear), columnar and then cuboidal.
what type of epi is ureter?and what type of muscle does its MM have?
transitional epi, smooth muscle
what type of epi does urethra in males and females have?
males: prostatic is transitional, membranous is also trans, penile is pseudostratified columnar initially then stratified squamous distally.
Females: transitional initially, st.sq distally
