What are the two parts of renal corpuscle ?
Glomerulus and Bowman's capsule
What is the parietal layer of Bowman's capsule
Simple squamous epithelium (Capsular layer)
What is the visceral layer of glomerulus
Modified simple squamous epithelial
What makes up the division between cortex and medulla
Arcuate Artery and Vein
Where does the capsular space become continuous with the lumen of the proximal convoluted tubule ?
The urinary pole
What are podocytes
Modified simple squamous epithelial cell
Stellate and unusual in shape
Several radiating primary processes give rise to secondary processes
Interdigitation
What are the components of basal lamina
The basal lamina of endothelial and podocytes.
Lamina rara externa (podocytes)
Lamina densa (intermediate)
Lamina rara interna (endothelial cells)
What is special about the pedicel surface ?
It has a coating of podocalyxin that is negatively charged
What are the characteristics of Endothelial ?
Thin and fenestrated when lines the capillaries
No diaphragm
Organelles are at the thicker unfenestrated cytoplasm
What is the function of filtration barrier ?
Filter the blood plasma
Permits water, ions and small molecules
prohibits protein molecules greater than 69k or negative charge
What are the components of filtration barrier
Fenestrated endothelium, basal lamina and the filtration slits
What is Mesangium ?
The interstitial spaces of the glomerulus between the capillaries
Contains mesangial cells and Extra Cell Material
What is mesangial cell ?
It helps maintain functional integrity of basal lamina by phagocytosing
It also contracts to decrease the surface area for filtration
It has receptors for angiotensin II and atrial natriuretic factor
What are the components of Nephron ?
Renal corpuscle, proximal convoluted tubule, thick descending proximal tubule, thin segment and ascending thick limb and distal convoluted tubule
What is the difference between cortical or juxtamedullary nephron ?
Cortical nephron has a shorter loop of Henle
What are the characteristics of Proximal Convoluted Tubule ?
The longest segment of nephron
Lines by a single layer of pyramidal shaped cells ( well developed brush border
Apical canaliculi for protein absorbtion (endocytic complex)
Lateral borders have extensive interdigitations
Extensive basal plasma membrane whi
What is the thick descending part of Proximal Tubule ?
It is lined by simple cuboidal with prominent brush border
Cells are shorter and less elaborate
Most often damaged in acute renal failure and mercury poisoning
Marks the Initial part of loop of Henle
What is the thin limb of the loop of Henle ?
Composed of thin descending limb, loop and thin ascending limb
Lined by simple squamous epithelium
The nuclei bulge into the lumen with short microvilli
The middle part of loop of Henle
What is the thick ascending limb of loop of Henle ?
It is the last part of loop of Henle.
Lined by simple cuboidal with few microvilli
The nuclei occupy an apical position
Mitochondria are compartmentalized within the interdigitations
Ions are transported out but is impermeable to water so luminal fluid is
What is Distal convoluted tubule?
It begins at macula densa.
Shorter microvilli with apical nuclei
Extensive lateral interdigitation compartmentalizes mitochondria
Actively transports sodium into the interstitium
What is Macula Densa ?
Specific region of the distal tubuel, lying near the afferent glomerular arteriole
Cells are tall, narrow and lined up closely
Monitor the fluid in the distal tubule
Signaling occur through gap junctions
What is the Juxtaglomerular Apparatus ?
It is located at the vascular pole of the renal corpuscle.
It consists of modified smooth muscle of afferent arteriole, efferent arteriole, the macula densa and the extraglomerular mesangial cells
What is the function of JG apparatus ?
In response to decrease extracellular fluid volume, it releases Renin
What is the function of Renin ?
It converts angiotensinogen to angiotensin 1
Angio 1 is converted to Angio 2 in Lung
What is the function of Angio 2 ?
It is a vasoconstrictor, leads to blood pressure elevation
Stimulates the release of aldosterone
What is the function of aldosterone ?
Stimulates the distal tubule to retain sodium ions
Retain water
What is the function of collecting tubule ?
It responds to vasopressin (antidiuretic) in cortex and medulla.
In medulla it concentrates urine
What causes the appearance of cell boundary in the collecting duct ?
Lateral interdigitation
What are the two cell types in the collecting duct ?
Principal cell
Intercalated cell
What is the function of principal cell ?
Light cells, reabsorb sodium and water
Secrete potassium
Simple cuboidal. centrally located nuclei
what is the function of intercalated cell ?
It secrete H+ or HCO3-
Reabsorb potassium
Fewer in number
Have microplicae (folds) on surface
What is the medullary collecting tubule ?
Intercalated cells appear in the outer region
Principal cells in the inner region
What is the papillary collecting tubule ?
It is a simple columnar epithelium.
Only has principal cells
Empties at cribrosa, on the apex of renal papilla
What is renal interstitium ?
It is the connective tissue compartment
What is cortical interstitium ?
Has fibroblasts and mononuclear cells
What is medullarly interstitium ?
Pericytes are present along the vasa recta
What is the component of ureter ?
Upper 2/3 has inner longitudinal and outer circular
Inner 1/3 has inner longitudinal, outer circular and outer longitudinal
What is the component of urinary bladder ?
Lined by transitional epithelium
Dome cells in resting
Muscularis: smooth muscle in inner longitudinal, middle circular and outer longitudinal
What are the division of male urethra ?
Prostatic (transitional epithelium)
Membranous (pseudostratified or stratified)
Cavernous
What is gland of Littre ?
It is a mucus-secreting gland
It locates at subepithelial connective tissue of urethra
What is at the distal end of the cavernous urethra ?
Fossa navicularis, lined by stratified squamous epithelium
What can you find in Pars Recta ?
The straight tubules.
Thick descending.
Loop of Henle
Thin Ascending
What can you find in Pars Convoluta ?
PCT
DCT
Where are the elipitical vesicles ?
They are found inside the cytoplasm near the apical phase of the dome cells.
What is the size of the filtration slit, the one formed between the interdigitation of podocyte processes ?
60 to 90 nm
What is the size of the fenestration slit, the one formed from the endothelial cells ?
20 to 30 nm