Urinary Histology Flashcards
Kidney functions
filtration selective resorption and excretion synthesis of renin synthesis of erythropoietin activates Vitamin D3
Three parts of the kidney cortex
glomeruli (renal corpuscles)
cortical labyrinth
medullary rays
How many renal lobes (pyramids) are in the medulla?
15-20
The bases of the medullary pyramids form the
corticomedullary border
What is the rounded end of each pyramid?
Renal papilla
Renal papilla drain up to ________ collecting ducts or ducts of Bellini
20
Medullary pyramid + overlying cortex
Kidney lobe
A group of nephrons that open into branches of the same main collecting duct. The space between two interlobular arteries with the medullary ray as its axis.
kidney lobule
Glomerulus + kidney tubules
Nephron
Nephron + collecting duct
Uriniferous tubule
Cortical nephrons have _______ Loops of Henle, while JM nephrons have ________ Loops of Henle.
short; long
Order of vasculature in the kidney
- interlobar artery
- arcuate artery
- interlobular artery
- interlobular vein
- arcuate vein
- interlobar vein
The glomerular filtrate is released into
the urinary (Bowman’s) space
Urinary pole is continuous with the
proximal convoluted tubule
The bulb-like expansion of the nephron is called _____________ and has a parietal layer of __________________.
Bowman’s capsule; simple squamous epithelium
Area of specialized cells within the distal convoluted tubule that is in contact with both the afferent and efferent arterioles
Macula densa
These cells are found between the afferent and efferent arterioles
extraglomerular mesangial cells
Modified smooth muscle cells in the tunica media of afferent and efferent arterioles
juxtaglomerular cells
Components of the JM apparatus
- macula densa
- extraglomerular mesangial cells
- juxtaglomerular cells
Distinct epithelial region found at the thick ascending limb-distal convoluted tubule junction.
Macula densa
Two things that fuse to form the basal lamina of glomerulus
Podocytes and capillary basal lamina
Three layers of the fused basement membrane
- lamina rara interna (capillary side)
- lamina densa
- lamina rara externa (visceral side)
Visceral layer of Bowman’s capsule contains
Podocytes (which contain primary and secondary processes)
These lie on the lamina rara externa and interdigitate to form up filtration slits
Pedicels (secondary processes)
Connective tissue component of glomerulus
Mesangial cells
Mesangial cells are derived from
mesoderm
Fluid leaving the glomerular capillaries through the fenestrae is filtered by
the basal lamina
____________ traps larger molecules, while the __________ impedes the passage of negatively charged molecules.
lamina densa; lamina rara
The fluid that penetrates the lamina densa and enters Bowman’s space
glomerular ultrafiltrate
These cells keep the basal lamina from becoming clogged by macromolecules by phagocytosing them
intraglomerular mesangial cells
Proximal convoluted tubule is made up of
simple cuboidal epithelium
The descending loop of the Loop of Henle is __________ to H20, while the ascending loop is ____________ to H20.
permeable; slightly permeable
Located in the distal convoluted tubule, and monitors filtrate for Na and Cl as part of the JGA apparatus
Macula densa
________ contain cells with abundant lysosomes.
Proximal convoluted tubules
The apical domain of PCTs has prominent __________ and __________. In contrast, the apical domain of DCTs has sparse _______________ and _______________.
microvilli; vesicles
JGA has three components.
- Macula densa of the DCT
- JG cells of afferent arteriole
- Extraglomerular mesangial cells
JM cells secrete this
Renin
These cells communicate
Cells of the macula densa and JG cells
2 types of cuboidal epithelium lining the collecting duct
- principal cells
2. intercalated cells
Minor calyxes mark the beginning of this type of epithelium
transitional
Layers of ureter
- mucosa
- muscularis externa
- adventitia
There are two layers of muscularis externa in the upper 2/3 of the ureter. The are….
There are three layers in lower 1/3 of ureter…
inner longitudinal, outer circular
inner longitudinal, middle circular, outer longitudinal
Bladder layers
- mucosa
- muscularis (inner long, middle circular, outer long)
- adventitia
Both male and female urethra have these
urethral glands
CT component of the glomerulus derived from mesoderm
Mesangial cells
These cells are phagocytic, contractile, and capable of proliferation
Mesangial cells
Mesangial cells secrete these two things
Matrix and collagen
Three important functions of mesangial cells
- provide physical support
- control turnover of basal lamina by phagocytic activity
- regulate blood flow by contractile activity
Because the basal lamina traps larger macromolecules, it would become clogged were it not continuously phagocytosed by _____________ and replenished by both the visceral layer of Bowman’s capsule (podocytes) and glomerular endothelial cells.
intraglomerular mesangial cells
How to identify a proximal convoluted tubule?
- adjacent to renal corpuscle (both PCTs and DCTs)
- cells have abundant lysosomes
- apical domain has a prominent brush border and vesicles (sparse in DCTs)
- cells lining both PCTs and DCTs have abundant mitochondria
Principal cells:
In the absence of ADH, urine flow is…
In the presence of ADH, urine flow is…
copious and hypotonic.
concentrated and low volume.
Intercalated cells secrete what and resorb what?
Where are they located?
H+; K+
Located in medulla and medullary rays
Papillary collecting tubules are lined with what kind of cells?
Tall columnar principal cells
In the bladder, fibroelastic adventitia is covered superiorly by peritoneum, forming a ________.
serosa
Epithelium of the bladder can be referred to as
urothelium
The columnar-like urothelium can stretch to resemble stratified squamous epithelium when urine is present in the urinary bladder. _________ generate a thickened domain able to adjust to large changes in surface area.
apical plaques
Two things common to male and female URETHRA
- vascular fibroelastic lamina propria
- urethral glands (glands of Littre in male)
Is the internal sphincter of the muscularis voluntary or involuntary?
Involuntary!
Does the mucosa of the URETER have mucosal or submucosal glands?
Does the mucosa have a muscularis mucosae?
No!!!
One contributing factor to the high rate of urinary tract infections in females
Short distance between the urethral opening and the anus
Female and male urethra ultimately become this kind of epithelium
stratified squamous, non-keratinized
PCT is made up of what kind of epithelium?
Simple cuboidal
The thin loops of Henle are made up of what kind of epithelium?
Simple squamous
What kind of cells are found in the collecting tubules?
Tall columnar principal cells
Where is the beginning of the transitional epithelium?
Minor calyces!
What is the prostatic urethra lined with?
Transitional epithelium
What is the membranous urethra lined with?
pseudostratified and stratified columnar
What is the penile urethra lined with?
pseudostratified and stratified columnar transitions to stratified squamous non-keratinized
