Histology - Urinary System Flashcards
composed of renal corpuscles, proximal convoluted tubules, and distal convoluted tubules
cortical labyrinth
impermeable to water but permeable to salts
ascending thin limb of Henle
when filtration rate is low…
macula densa cells stimulate juxtaglomerular (granular) cells to increase release of the protease enzyme renin into the blood
separates renal pyramids from one another
renal columns (of Bertin)
stimulates bone marrow to produce RBCs
erythropoietin (EPO)
aldosterone
causes greater sodium reabsorption from distal tubules and collecting tubules, which then triggers the release of antidiuretic hormone (ADH) from the pituitary gland to increase blood volume and blood pressure (and concentrate urine)
afferent glomerular arterioles
supply renal corpuscles
absence of ADH
makes collecting tubules impermeable to water and allows urine to be dilute (hypotonic) and have high volume
EPO produced by
peritubular capillary cells, chronic kidney diseases may result in anemia
thin inner and outer longitudinal smooth muscle layers, with a thick middle circular smooth muscle layer that forms the internal urethral sphincter muscle around the internal orifice of the urethra
bladder muscularis (detrusor muscle)
impermeable to water but permeable to salts, sodium reabsorption increases in response to aldosterone from adrenal (suprarenal) cortex
distal tubule of nephron
Modified smooth muscle cellsbetween capillaries. They have phagocytic activity, removing proteins and other molecules trapped in the glomerular basement membrane or filtration barrier.They secrete interleukin 1 and platelet derived growth factor to aid in repair.
intraglomerular mesangial cells
the initial blood-filtering component of a nephron. It consists of two structures: a glomerulus and a Bowman’s capsule.
renal corpuscle
Mucus secreting glands in lamina propitia of urethra.
glands of Littre
ADH stimulates
the insertion of aquaporins into the plasma membrane of principal cells (light cells) to allow water to move from lumen into cells; majority of cells lining the collecting tubule are light staining principal cells
purpose of the renal system
eliminate wastes from the body, regulate blood volume and pressure, control levels of electrolytes and metabolites, and regulate blood pH.
external urethral sphincter
skeletal muscle fubers where urethra pierces perineum
permeable to water and salts, active transport of sodium by Na+/K+ ATPase pumps, passive diffusion of water through aquaporins (water channels)
proximal tubule of nephron. Reabsorption back into blood supply of 65 - 70% of water, sodium, and chloride, as well as 100% of proteins, amino acids, and glucose.
collecting tubules derive from
ureteric bud
overlies base of renal pyramid
cortical arch
peritubular capillary network
supplies tubule system
loose connective tissue in cortex contains cells that resemble fibroblasts, and occasional macrophages, while in medulla it contains cells that resemble myofibroblasts
renal interstitium (stroma), reabsorbed water and other molecules pass from nephron and collecting tubule into renal interstitium and then into blood supply
nephron chief function
regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.
transitional epithelium 3-5 cells thick, lamina propria of dense irregular fibroelastic connective tissue
ureter mucosa
disease characterized by low ADH production
neurogenic or central diabetes insipidus
distal tubule between pars recta and pars convoluta, near the afferent and efferent glomerular arterioles (vascular pole), tall narrow cuboidal cells whose nuclei are close together
macula densa cells
kidney lymphatic supply
superficial and deep lymph vessels follow larger arteries, form larger lymph vessels near the hilum, and then travel to lymph nodes near the abdominal aorta and inferior vena cava.
renal innervation
sympathetic nerve fibers from renal plexus innervate blood vessels, renal tubules, juxtaglomerular cells, interstitial cells, and the kidney capsule
contains mechanoreceptors sensitive to stretch
trigone
has folded transitional epithelium as mucosa
empty bladder
granular cells of afferent glomerular arteriole, modified smooth muscle cells that contain granules of protease enzyme renin
juxtaglomerular cells
proteins < 5 kD
freely permeable across filtration apparatus, while proteins > 75 kD are impermeable
similar in appearance to capillary pericytes but unknown function
extraglomerular mesangial cells
conspicuous lateral plasma membranes
collecting tubule
renal pyramid + associated cortical tissue at base and sides
lobe
contains medullary rays and cortical labyrinth, that together comprise a lobule
cortex
is apex of renal pyramid, contains area cribrosa (with about 20 papillary ducts of Bellini) and empties into minor calyx
renal papilla
urinary plaques
thickened reginos of plasma membrane that associate with actin filmaments and invaginate in relaxed urinary bladder. Appear as “vesicles” in TEM, but their lumen is continuous with cell exterior.
stimulates the angiotensin pathway in the blood, leading to an increase in aldosterone release from the adrenal (suprarenal) cortex
Renin
bladder serosa location
present in regions with a peritoneal reflection onto the wall of the urinary bladder
prevent regurgitation of urine from bladder back into ureters
flap of mucosa hanging over ureteric orifice
contains renal pyramids, cortical arches, and cortical columns
medulla
medullary ray + surrounding cortical labyrinth
lobule
renin-angiotensin-aldosterone system (RAAS).
low filtration rate -> MDC stimulate JGC to release renin. Renin -> angiotensin pathway -> increased aldosterone from adrenal cortex. Aldosterone -> greater sodium reabsobtion from distal tubule and collecting tubules, which triggers ADH from pituitary gland to increase blood volume and pressure.
filtration apparatus
Part of renal corpuscle. Contains: fenestrated endothelial cells of glomerulus (without diaphragms), thick basal lamina from podocytes and glomelular endothelial cells, filtration slit diaphragm between pedicels
dense irregular collagenous connective tissue. myofibroblasts, function unknown
kidney capsule
disease characterized by inability to respond to ADH
nephrogenic diabetes insipidus (ex. Mutation of aquraporin gene)
nephrons derive from
metanephric blastema
a hormone system that regulates blood pressure and water (fluid) balance.
renin-angiotensin-aldosterone system (RAAS). If abnormally active, blood pressure too high.
ureter layers
mucosa, NO submucosa or muscularis mucosa, muscularis (inner long., outer circ., outer long. For distal third), and adventitia
composed of collecting tubules, and thick descending and ascending limbs of Henle’s loop; appear to radiate from medulla
medullary rays
three regions of male urethra
prostatic urethra (transitional epi), membranous urethea (stratified columnar), spongy penile urethea (strat. Columnar w/ patches of psuedostrat and strat squamous).
stratified epithelium located exclusively in urinary system, impermeable barrier to urine
transitional epithelium (urothelium). - characteristic dome-shaped cells facing lumen that flatten out in full urinary bladder. Often BINUCLEATE.
secrete H+ or HCO3- into lumen to maintain appropriate urine pH;
intercalated cells (dark cells)
permeable to water but impermeable to salts
descending thin limb of Henle
composed of collecting tubules, thick descending and ascending limbs of Henle’s loop, and thin limbs of Henle’s loop
renal (medullary) pyramids
autoimmune response to collagen type IV that affects GBM of renal corpuscles. Symptoms include: hematuria and proteinuria. Also affects alveolar BM. Treatment includes plasmapharesis, coticosteroids, and immunosuppressive drugs.
Goodpasture syndrome
presence of ADH
makes collecting tubules permeable to water and allows urine to be concentrated (hypertonic) and have normal volume
