Renal Histology Flashcards
THe renal pelvis empties into what stucture_
The renal pyramids.
What is the blood supply of the kidney?
the renal artery.
What is the functional unit of the kidney?
the nephron.
What are the components of the nephrons?
Bowmans Capsule
Glomerulus
Renal tubule
What do nephrons empty into?
Collecting ducts, which empty into the renal pelvis.
What are the two types of nephrons?
cortical nephrons
juxtamedullarz nephrons
Where are the renal corpuscles of the cortical nephrons located?
in the cortex
Where are the renal corpuscles of the juxtamedullary nephrons located?
in the cortex next to the cortical medullary junction.
What do the glomeruli of the cortical nephrons empty into_
capillary networks that surround the proximal and distal convoluted tubules.
What do the glomeruli of the juxtamedullary nephrons empty into_
The vasa recta.
What is the difference between the loops of Henle in cortical and juxtamedullary nephrons?
The cortical nephrons have short loops of Henle, and the jutxtamedullary nephrons have long loops of Henle that extend into the medulla.
What is the movement of blood through the kidney?
afferent arterioles
Glomeruli
efferent arterioles
How do the arterial and venous portal systems differ?
The arterial portal system involves movement of blood from afferent, to capillary to efferent arterioles.
The venous portal system involves movement from arterioles to capillaries to veins.
What is the glomerulus?
A capillary bed inserted betweent two arterioles, the afferent and efferent arterioles.
What does the afferent arteriole feed into?
A capillarz loop (vasa recta) or a capillary network (peritubular capillaries)
What are the components of the urinarz szstem_
two kidneys and ureters
The urinary bladder and urethra
What type of cells around found at the afferent arteriole?
Juxtaglomerular cells.
They secrete renin.
What is the Bowman’s capsule?
A double lazered, cup shaped dilation of the nephron.
It consists of an inner (parietal) and outer (visceral) lazer.
What type of epithelium is found in the parietal layer?
simple squamous epithelium.
The epithelium of the parietal layer is continuous with the proximal convoluted tubule. What type of epithelium is found at the proximal convoluted tubule?
squamous epithelium
THe visceral layer is made of podocytes: The podocytes are in contact with the endothelium of what?
glomerular capillaries.
Where is the Bowman’s space located in relation to the parietal and visceral layers_
between the parietal and visceral layers.
What portion of the nephron is involved in producing a filtrate of blood?
renal corpuscle
What portion of the neprhon is involved in modifying the filtrate produced bz the renal corpuscle?
The convulted tubules and loop of Henle.
What three proceses are involved in the formation of urine?
Filtration
Reabsorption
Secretion
Filtration occurs in the renal corpusclee and reabsorption and secretion occur in the renal tubule.
Whatever is filtrated and secreted, but not reabsorbed, is also known as what?
urine
What is the mesangium part of?
The glomerulus
What is the mesangium formed bz?
Mesangial cells embedded in a mesangial matrix.
Intraglomerular msangial cells serve what function?
Thez cover endothelium not covered by podocytes.
Extraglomerular mesangial cells are located between what two arterioles? What apparatus are they associated with?
Efferent and afferent arterioles. They are associated with the juxtaglomerular apparatus.
What are the two main characteristics of mesangial cells?
They are contractile (useful for filtration) and phagocytic (phagocytize immunoglobulins trapped in the basal lamina)
What are two substances secreted by mesangial cells?
prostaglandins and endothelins
What are two substances synthesized by mesangial cllsÖ
matrix and collagen.
What are the function of mesangial cells?
They provide mechanical support and regulate blood flow.
Mesangial cells respond to what protein?
angiotensin II
What are the components of the juxtaglomerular appartus?
Macula densa
Extraglomerular mesangial cells
Juxtaglomerular cells
Where are macular densa cells found?
the wall of the convoluted tubule.
Macula densa cells respond to changes in what two ions?
sodium and chloride
The macula signal the release of what protein from juxtaglomerular cells?
renin
What is the importance of the macula densa?
regulation of fluid electrolzte balance and blood pressure.
What type of muscle cells are juxtraglomerular cells?
Smooth muscle cells.
The juxtaglomerular cells are associated with what cells and arteriole?
macula densa and afferent arteriole
When stimulated by the macula densa, what hormone do juxtaglomerular cells secrete?
Renin
What is the purpose of innervation of the juxtaglomerular cells?
Thez increase renin release.
The distal convoluted tubule is continuous with what duct?
collecting duct
What are the components of the renal filtration barrier?
fenestrated endothelium (of glomerular capillaries)
fused basal laminae of endothelial cells
filtration slits
The basal lamina of the filtration slits consists of what components?
Type IV collagen
Fibronectin
Laminin
Heparin Sulfate
What is the renal filtration barrier selective to?
Water, glucose and most ions.
It is not selective to proteins or molecules with a large negative charge.
Where is the proximal convoluted tubule?
From the renal corpuscle to the beginning of the loop of henle.
What tzpe of epithelium is found at the proximal convoluted tubule?
Simple cuboidal epithelium with pyramidal cells.
The proximal convoluted tubule contains what type of juctions?
tight junctions. It also contains a brush border.
The proximal convoluted tubule contains many mitochondria. Why is there an abundance of them in this region?
TO allow for active transport across the basal membrane.
True or false: the proximal convoluted tubule reabsorbs most of the filtrate
True
What does the proximal convoluted tubule reabsorb?
most of the sodium and chloride ions.
The proximal convoluted tubule removes what from the filtrate?
glucose and amino acids.
