28/29 Urinary System Flashcards
direction of kidney flow
apex of each pyramid (renal papilla) –> MINOR calyx –> MAJOR Calyx –> RENAL PELVIS –> URETER
The nephron begins with _______ which is made up of ___ and ___
RENAL CORPSUCLE : Bownmans capsule and Glomerular Capillaries
From Bowmans capsule the filtrate flows through the tubular portions (2-6) of the nephron until it reachse what portion of the nephron
DISTAL CONVOLUTED TUBULE
After the last portion of the nephron, the filtrate enters ______
collecting tubule that fuse to form the papillary fucts that empty the modified ultrafiltrate = urine into MINOR CALYX
Where does the papillary duct empty into?
into calyx at renal papilla
What are the two types of nephrons – based on location
Superficial Cortical Nephron
Juxtamedullary Nephron
The visceral layer in the development of a renal corpsucle is due to
what happens to the visceral layer
glomerulus of capillaries causes invagination of cells in the future bowmans capsule
These cells become PODOCYTES that wrap around capillaries
How is the glomerular basement membrane developed
Basal Laminas of capillaries and future podocytes fuse to form the thick multilayered GBM
In the Renal corpuscle, where does the blood ENTER , filtration occurs through 3 structures and then where does it EXIT
Afferent Arteriole –> Capillaries, Basement Membrane, Podocytes –> Efferent Arteriole
The third part of the glomerular filtration barrier =
FILTRATION SLIT = space between podocyte foot processes and has thin diaphragms
Blood is FILTERED BASED ON what?
SIZE and CHARGE
there should be VERY LITTLE protein in the filtrate just lots of water and very small ions (glucose, amino acids and urea)
Where are mesangial cells found? and functions?
in and around glomerular capillary loops
Support – secretes thin CT matrix = MESANGIUM
Cleaning – phagocytosis of debris
Contractile
This apparatus has several structues at the vascular pole that work together to maintain blood pressure and maintain glomerular blood flow and filtration
JUXTAGLOMERULAR APPARTUS
cluster of dark, compact cells in one side of the distal tubule next to the renal corpuscle, between arterioles. cells monitor the sodium concentration (osmolarity) of the filtrate
MACULA DENSA
modified smooth muscle cells in the afferent arteriole. these cells contain granules with RENIN. releases renin into the blood which increases blood pressure via renin-angiotensin-aldosterone system
JUXTAGLOMERULAR CELLS
Major site of REABSORPTION of glucose, amino acids, polypeptides, water and electrolytes
Simple CUBOIDAL epithelium, Basal STRIATIONS, Kinky/ragged lumen, microvilli, acidophilic and has indistinct lateral cell borders
PCT = proximal convoluted tubule
ID in cross section
STRAIGHT portion of PCT
TDL = thick descending loop of henle
ID will be longtidunal
simple squamous epithelium apart of loop of henle
TL = thin limb of loop of henle
straight portion of DISTAL tubule has the same features as DCT
TAL = thick ascending limb
this portion of tubule has simple cuboidal epithlium with indistinct borders but when compared to PCT this has fainter basal striations, less acidophilic cytoplasm, few microvilli, more nuclei in section
DCL = DISTAL CONVOLUTED TUBULE
this tubule has simple cuboidal cells with VISIBLE DISTINCT lateral cell borders and pale cytoplasm
COLLECTING TUBULE/DUCT
similar to collecting tubule but has simple columbar cells
PAPILLARY DUCT
Cortical Labyrinth = balls and straight
Renal Corpuscle and PCT/DCT
Medullary Ray in the CORTEX = straight pieces no balls
thick/thin descending limb of Henle and Collecting tubules/ducts
Medulla contains STRAIGHT PIECES
thick descending, thick ascending limbs, collecting ducts AND thin loops of henle, papillary ducts
Arteriole Portal System = unique to kidney
Two capillary beds connected by an arteriole portal vessel
these arteries provide an afferent arteriole to each nephron
INTERLOBULAR ARTERIES
Efferent arterioles from CORTICAL nephrons give rise to what
PERITUBULAR CAPILLARIES around convoluted tubules (IN THE CORTEX)
Efferent arterioles from JUXTAMEDULLARY NEPHRONS
enter the medulla where it gives rise to the vasa recta capillaries that parallel the long loops of henle
Peritubular Cappilaries provide oxygen and nutrients to what type of tissue
CORTICAL tissue including convoluted tubules and serve as a pathway for return of reabsorbed water and solutes to the blood
VASA RECTA capillaries provide oxygen and nutrients to what type of tissue
MEDULLARY tissue along with the loop of Henle, helps produce concentrated urine through a countercurrent exchange system
double walled cup receiving urine from the papillary ducts at the tip of each pyramid
MINOR CALYX
Renal Pelvis, Ureter and Urinary bladder have similar structures
What type of epithelium?
Transitional Epithelium (urothelium)
CT (lamina propria) with a muscularis layer of smooth muscle in poorly defined layers
What do rounded umbrella cells indicate versus flattened umbrella cells
ROUNDED – relaxed, empty bladder
FLATTENED – distended (FULL) bladder
antigen-antibody complexes can become trapped in GBM, leading to filtration barrier damage or auto antibodies directed to attack the GBM could be produced
GLOMERULAR DAMAGE – associated with many autoimmune diseases and mediated by antibodies
these diseases affect the kidney secondarily
artiolosclerosis and associated hypertension = major cause of chronic glomerular injury and renal failure
CIRCULATORY DISEASES
leading cause of end-stage renal disease and a major cause of death in diabetic patients
causes a thicker and leaky GMB
arteriole lumen narrows
leads to ischemia and tubular atrophy
DIABETES MELLITUS
even short interruptions of blood supply such as shock and heart failure can result in tubular necrosis
WHAT TUBULE IS FIRST EXPOSED AND DAMAGED BY DRUGS and hazardous waste products in the ultrafiltrate
DAMAGE to RENAL TUBULES
PCT = first damaged
most common malignant kidney in children, composed of immature mesenchyme (blastema) cells with primitive glomeruli and tubules
WILMS TUMOR
