Jan3 M3-Histology Urinary System Flashcards
capsule around the kidney
tough layer of dense CT (fibrocytes and collagen)
cortex vs medulla appearance
cortex: grainy bc of glomeruli
medulla: striated and organized into lobules
imaginary line between cortex and medulla
corticomedullary junction
name of medullary lobules + orientation
medullary pyramides. face towards cortex. tip or papilla towards minor calices
name of structure between medullary pyramids
columns of Berlin
columns of Berlin def
cortical tissue (interlobar) and CT
area cribrosa def
area perforated by the tip of a pyramid where collecting ducts will end
spaces in which fluid goes after medullary pyramids (3)
minor calyx and then major calices (larger)
pelvis
renal corpuscle def
glomerulus + Bownman’s capsule
P in glom cap system and why
high P bc between two arterial systems
3 components of loop of Henle
thick descending, thin descending, thick ascending limbs
collecting tubule vs collecting duct
tubule = in medulla duct = in cortex. larger and more obvious
3 names for the region where CD opens (into minor calyx) = how large it is
tip of pyramid, papilla of pyramid, papillary ducts of Bellini. very large
name for the whole structure formed by the nephron + collecting tubules
uriniferous tubule
embryo sorigines of the uriniferous tubules and what structures each one gives
metanephric blastema (or metanephric mesenchyme): corpuscule to DCT ureteric bud: CTs and CDs
Bowman’s capsule 2 components and where they join
parietal layer: flat simple squamous epithelial
visceral layer: podocytes
join at vascular pole of the corpuscule
charact of podocytes
have processes that interdigitate
where capsular space opens into PCT
at the urinary pole of the corpuscule
how many glom capillaries
5-6
special cells found in AA name + fct + type
juxtaglomerular cells, epithelial cells in the media (from transformed SM), secrete renin
normal shape of cells in the DCT and exception (near what 2 things and what cell type)
cuboidal. when DCT passes near vascular pole and the AFFERENT arteriole, epithelial transformation in columnal cells: macula densa
3 components of the parietal layer of Bowman’s capsule
squamous cells, BM and reticular fibers
types of processes of podocytes
primary processes. secondary processes are called pedicels and pedicels of adjacent podocytes will interdigitate
glom capillaries: what type
fenestrated
glomerular BM (GBM) shared by what
endothelial cells (capillaries), pedicels and mesengial cells
mesengial cells where and functions
between glomerular capillaries, below the BM so don’t touch podocytes. recycle (eat) ECM
2 types of mesengial cells and location
intraglomerular (between glom caps below BM)
extraglomerular (between AA and EA)
do extra and intraglom cells connect? final structure is what
extraglomerular mesengial between AA and EA continuous with intraglomerular mesengial which touch the capillaries. BM separates all that from podocytes that are on other side.
filtration slit def
space between 2 pedicels where small diaphragm (similar to BM) is present
filtration slit size and what doesn’t pass
25 nm. negatively charged proteins and proteins greater than albumin (70 kDa) don’t pass
2 functions of mesengial cells
- phagocytosis of particles, germs, ECM, BM and structural support of capillaries
- secrete cytokines
medullary rays def
linear extension of the medulla into the cortex. small medullary portions that penetrate deep in the cortex
area cribrosa def
area at tip of medullary pyramid where all openings of CDs are present
minor calyx comes after what + 2 components of minor calyx
space after CDs. wall of minor calix and lumen of minor calix
PCT diameter, cells type and staining
60 um. columnar. acidophilic.
PCT cells 2 charact and purpose
microvilli (brush border) to increase abso on lumen side
folds of basolateral membrane with mts to provide energy for NaK pumps
absorption mode in PCT other than channels
endocytosis of albumin and glucose
tight junctions too
TDL charact
similar to PCT
tDL diameter and cell type and what structure below the cells
12 um, flat simple squamous. rest on BM
loop of Henle: what absorbs water
THIN descending limb only
TAL charact
similar to DCT
DCT diameter, cell type, stain, microvilli or not
60 um. cuboidal. less acidophilic (eosinophilic), few or no microvilli
DCT what’s at the base
NaK ATPase under control of aldo
DCT 2 functions
- abso Na and secrete K
2. abso bicarb and secrete H+
nuclei location in PCT vs DCT
PCT: not close to apical plasma membrane
DCT: close to apical plasma membrane
TDL location
medullary rays and upper part of medulla
TDL cell type, stain, microvilli or not, histo look
columnar cells, acidophilic, microvilli, dirt in lumen on histo
thin limb location and description
in medulla. is mainly descending (so TDL but has small ascending part)
TAL location and cell type
medulla and medullary rays. cells are cuboidal and short
TDL vs TAL nuclei location
TDL: not kissing apical membrane
TAL: kissing apical membrane
collecting tubules location, stain and cell type
cortex and medullary rays. like DCT, don’t stain well with eosin. cuboidal cells
CTs 3 characteristics to recognize them (and diff from DCT)
- visible lateral plasma membranes
- nuclei not kissing apical plasma membrane
- cells bulging into lumen
CDs location
medulla
CDs 2 charact + cell type
- prominent lumen
- visible lateral plasma membranes
columnar cells
what is found below all tubular cells and why
BM. (bc are epithelial cells)
thing happening at CDs
site of ADH action, produced by pituitary gland
summary of cell types in the tubules
PCT: columnar TDL: columnar tL: squamous TAL: cuboidal DCT: cuboidal CT: cuboidal CD: columnar
juxtaglomerular apparatus components
macula densa and juxtaglomerular cells
charact of juxtaglomerular cells
epihtelial-like, in media of AA, with large secretory granules
renin what precise type of molecule
enzyme (not a hormone). is an endocrine secretion bc goes in blood. aspartyl peptidase
renin function
removes some a.a from angiotensinogen (produced by the liver) to yield ATI (10 a.a)
ACE function and location
surface of endothelial cells of lung capillaries. removes 2 a.a from AT1 to make AT2
AT2 functions
contracts arterioles, increases BP, stimulates prod of aldosterone
macula densa fct + how communicates with juxtaglomerular cells
detect Na conc in filtrate and produce NO to relax SM of AA
arterial supply to the kidney until glomerulus
renal artery (hilum), interlobar arteries (between pyramids), arcuate artery (90 degree rotation to become horizontal at corticomedullary jct), lobular arteries (90 d rotation back up in the cortex, to the glomeruli), AA
arterial supply to the kidney at and after the glomerulus
AA - glom caps - EA - peritubular capillaries or vasa recta
peritubular capillaries function
produce EPO
venous drainage in the kidney
capillary network under renal capsule + peritubular capillaries drain in stellate veins. lobular veins, arcuate vein (also receives from vasa recta), interlobar vein, renal vein, all that parallel to arterial system.
name of glomeruli near corticomedullary junction and how they are different
juxtamedullary renal corpuscules. don’t form peritub capillaries but rather vasa recta: very long capillary
vasa recta origin, location and where it drains
comes from EA of juxtamedullar corpuscules. parallel to the loop of Henle and drains in the arcuate vein (which travels parallel to the corticomedullary junction)
vasa recta and loop of Henle function
countercurrent multiplier to make interstitium salty
vasa recta on histology
in medulla, beside thin limb. appear pink on cross section, small, surrounded by endoth cells
Addison Disease (or Chronic Adrenal Insufficiency) def
chronic endocrine disorder where not enough steroid hormones prod by adrnals (includes aldo so excessive loss of Na in urine + low BP)
