Urinary System Flashcards
List the cells comprosing the juxtaglomerular apparatus
Macula densa, juxtaglomerular cells, extraglomerular mesangial cells
State the flow of urine starting with renal pyramids and ending with the ureter
Renal pyramids > [renal papilla > area cribosa] > minor calyces > major calyces > renal pelvis > ureter
What structures possess transitional (urinary) epithelium?
Minor calyces to bladder (prostatic urethra in males)
Generally, the renal cortex can be subdivided into what two sections?
Pars recta, pars convulata
What structures come together to form a renal lobe?
Renal pyramid with its associated cortical tissue
What structures come together to form a renal lobule?
Medullary ray and its associated cortical tissue
T/F: All nephrons within a renal lobule are drained by the same collecting duct
True
State the flow of blood through the kidney starting with the renal artery and ending with the efferent glomerular arteriole
Renal a. > segmental a. > lobar a. > interlobal a. > arcuate a. > interlobular a. > afferent a. > glomerulus > efferent a. > vasa recta
Longer loops of Henle allow juxtamedullary nephrons to form what type of urine?
Hypertonic
In what part of the nephron would you find eosinophilic, simple cuboidal epithelium with central, euchromatic nuclei that possess lots of microvilli and basal striations?
PCT
In what part of the nephron would you find smaller simple cuboidal epithelial cells that possess many more basal striations and an apically located nucleus, but with few microvilli?
DCT
In what part of the nephron would you find simple squamous epithelium with ‘tootsie roll’ wrapped cytoplasm also buldging into the lumen?
LOH
In what part of the nephron woud you find simple cuboidal epithelium which show copious lateral interdigitations (even in LM) that facilitate the absorption of water?
Collecting duct
What connects adjacent pedicels?
Slit diaphragm (made of nephrin protein)
What negatively charged coating layers pedicel surfaces?
Podocalyxin
The fused basal lamina of capillary endothelial cells and podocytes possesses what three structures?
Lamina rara interna, lamina dense, lamina rara externa
What structures comprise the interstitial space of the glomerulus?
Mesangium
What is the housekeeping function of mesangial cells?
Maintain functional integrity of basal lamina by phagocytosing molecules and/or debris
What filtration/homeostatic function(s) do mesangial cells possess?
Able to contract (decrease surface area/lumen size), possess receptors for angiotensin II and ANF
What material(s) is/are absorbed by PCT cells?
80% of NaCl, water; All glucose, amino acids, small proteins
Between the PCT and DCT, which tubule is recognized as having a more clear luminal appearance?
DCT
Between the PCT and DCT, which tubule is recognized as having more microvilli?
PCT
The thin LOH can be furthre broken down into four segments based on what features?
Cell shape, organelles, depth of tight junctions, and water permeability
Name an effect of angiotensin II
Stimulates release of aldosterone from zona glomerulosa, acts as potent vasoconstrictor, act on glomerular mesangial cells
As renal tubule cells are active in their absorption of (x), (y) are present in copious amounts, making their (z) stand out in LM
Water (x), lateral interdigitations (y), lateral borders (z)
Explain a logical sequence of light cells/dark cell mechanisms beginning with aldosterone induction
Aldosterone acts on light cells to intake sodium/output postassium, dark cells then intake potassium/output hydrogen ion (possibly from carbonic acid production), dark cells may also secrete bicarbonate to balance charges
Where are dark cells located?
Corticol collecting tubules, outer medullary collecting tubules
Which structure acts as a landmark between the cortex and medulla?
Arcuate artery
State the main function of the urinary system
Clear the blood of waste products, regulate body fluid concentration
State the flow of urine starting with the urinary space in the glomerulus and ending with the collecting duct
Urinary space > PCT > thick descending limb > LOH > thick ascending limb > DCT > collecting tubule > collecting duct
If an individual would desire to retain more water, which type of nephron would better suit this need?
Juxtamedullary
With regards to the visceral layer of Bowman’s capsule, what two layers are known to be fused?
Basal laminas of podocytes and capillary endothelial cells
State the different parts of the nephron
Renal corpuscle, PCT, descending thick limb, LOH, ascending thick limb, DCT
What structure is on either side of a glomerular capillary fused basal lamina?
Endothelial cell (+fenestrations), pedicels
T/F: Only compounds can/cannot pass through filtration based on their size, but not their charge
False
What structures comprise the pars convulata?
Glomerulus, PCT, DCT
What structures comprise the pars recta?
All straight tubules: thick descending LOH, thick ascending LOH, collecting tubules/ducts
Cells of the thick descending LOH possess the same general features as which other nephron segment?
PCT
Cells of the thick ascending LOH possess the same general features as what other section of the nephron?
DCT
Describe the epithelium of the thin LOH
Simple squamous epithelium, nuclei buldge into the lumen, ‘wrapping’ cytoplasm protrude with cells
Thick ascending LOH cells are (x) to water; thus the luminal fluid in this area becomes (y)
Impermeable (x), hypotonic to blood (y)
Macula densa cells lie in the (x) while JG cells are in the (y)
DCT (x), afferent arteriole (y)
Macula densa cells are thought to sense (x) in the nephron lumen, which signal JG cells to release (y)
Low sodium concentration (x), renin (y)
(x), produced by JG cells, acts on (y) which is produced in the (z)
Renin (x), angiotensinogen (y), liver (z)
(x) is cleaved by renin to produce (y) in the (z)
Angiotensinogen (x), angiotensin I (y), blood (z)
Angiotensin I travels to the (x), where (y) converts it to (z)
Lungs (x), ACE (y), angiotensin II (z)
Explain the mechanism of increasing sodium retention by aldosterone
Aldosterone acts on renal tubule light cells to retain sodium, which when followed by water increases blood volume
Collecting ducts are also called (x) and are comprised of only (y)
Ducts of Bellini (x), light cells (y)
Subendothelial glands, termed (x), are present along the length of the male urethra and secrete (y)
Glands of Littre (x), mucous (y)
Name two types of nephritis which may occur within the glomerulus
Mesangial, podocyte nephritis
Which examples were given in class as affecting the descending LOH?
Acute renal failure, mercury poisoning
Which hormone does the kidney produce that stimulates RBC production?
Erythropoietin
What enzyme does the kidney produce that influences blood pressure and body plasma sodium concentration?
Renin
T/F: The renal hilus is continuous with the renal sinus
True
What is the name for the structure that can be described as a funnel-shaped expansion of the upper end of the ureter?
Renal pelvis
What is an alias for medullary rays?
Pars recta
What structure is located at the apex of each renal pyramid?
Renal papilla
What structure is located at the tip of each renal pyramid?
Area cribosa
What is an alias for a renal collecting duct?
Duct of Bellini
Nephrons can be classified as either (x) or (y) depending on their location
Corticol, juxtamedullary
What is an alias for secondary podocyte processes?
Pedicels
The DCT begins at which location?
Macula densa
Which hormone acts on the collecting tubule
ADH (vasopressin)
T/F: A single central cilium/flagellum extends into the lumen from the surface of each light cell
True
What cells are present in the renal institium of the cortex? medulla?
Cortex: fibroblasts/mononuclear cells; Medulla: pericytes, unknown cell
(x) underlies the bladder’s urinary epithelium, underneath which lies (y)
A thin basal lamina (x), fibroelastic CT (y)
T/F: As the kidneys are retroperitoneal, they are lined externally by mesothelium
False
What is the histological term for medullary extensions that break into the renal cortex?
Medullary rays
What is an alias for the columns of coritcal tissue projecting between renal pyramids?
Renal columns of Bertin
T/F: The nephron and collecting tubule(s) originate from separate primordia
True
Which type of nephron has shorter LOHs?
Corticol
Which type of nephron has longer LOHs?
Juxtamedullary
Approximately what percentage of the pars convulata is comprised of PCTs?
80%
The renal corpuscle is comprised of which two structures?
Glomerulus, Bowman’s capsule
What type of epithelium lines the outer wall (parietal layer, capsular layer) of Bowman’s capsule?
Simple sqamous epithelium
What type of structure lines the glomerular capillaries?
Modified simple squamous epithelium (podocytes)
What is the region termed where the afferent and efferent arterioles enter and leave the glomerulus, respectively?
Vascular pole
What is the region termed where the urinary space enters into the PCT?
Urinary pole
T/F: Podocytes only have primary processes
False
What type of capillaries are found in the glomerulus?
Fenestrated
T/F: Slit diaphragms are found spanning glomeruli endothelial cell fenetrations
False
What are the components of glomerular ultrafiltrate?
Water, ions, small molecules
The mesangium contains what material(s)?
Mesangial cells, ECM
Which part of the nephron is the longest?
PCT
T/F: PCT cells are highly active in protein absorption
True
T/F: PCT cells do not possess lateral borders with extensive interdigitations
False
T/F: PCT cells play a role in plasma acid/base balance
True
T/F: Hydrogen ions are secreted in exchange for bicarbonate ions at the PCT
True
T/F: The thin LOH is comprised of descending, middleand ascending parts
True
Cells of the thick ascending LOH possess (x) nuclei and many (y)
Apically-located (x), basal striations (y)
T/F: DCT cells possess extensive lateral interdigitations
True
T/F: JG cells are believed to be modified smooth muscle cells
True
What junctional complexes might allow the communication of cells in the JG apparatus?
Gap junctions
T/F: The JG apparatus is located at the urinary pole of the glomerulus
False
T/F: Collecting tubules possess similar functions despite their location in the kidney
False
In the medulla, (x) is transported into the renal interstitium via collecting tubule cells
Urea
What are aliases for light and dark cells of the collecting tubule?
Light/principal, dark/intercalated
Where would the nuclei be located in each cell type: light cell? dark cell?
Centrally (light), apical (dark)
T/F: Dark cells are fewer in number than light cells
True
How many layers of smooth muscle are present in the ureter?
Upper two/thirds: 2 lower third: 3
The ureter lumen has a (x) appearance
Stellate
The bladder possesses (x) epithelium which is connected via (y)
Transitional (x), junctional complexes (y)
T/F: Junctional complexes usually break when their attached cells are distended, except in the bladder
True
As the lower ureter has (x) muscular layers, so does the bladder
Three
What are the different partitions of the male urethra?
Preprostatic, prostatic, membranous, cavernous (spongy)
What types of epithelium lines the male urethra?
Transitional, stratified columnar, pseudostratified columnar
What types of epithelium lines the female urethra?
Stratified squamous, psuedostratified columnar
