Histo Urinary System Flashcards
What are the components of the urinary system?
kidneys and urinary tract
What is the function of the kidneys?
filtration – kidney glomeruli
selective resorption and excretion – kidney tubular system
synthesis of renin (regulates blood pressure via renin-angiotensin system)
synthesis of erythropoietin (regulates RBC production via [O2]
produced by interstitial fibroblast of the kidney
activates Vitamin D3
In the kidney, what is responsible for filtration?
kidney glomeruli
In the kidney, what is responsible for resorption and excretion?
kidney tubular system
In the kidney,what is responsible for the synthesis of renin?
RAAS
In the kidney, what is responsible for the synthesis of erythropoietin?
interstital fibroblast of kidney
What regulates bloodpressure via the RAAS?
renin
What regulates RBC production via decreased amount of Oxygen?
erythropoietin
What activates vitamin D3?
the kiDney
Is the kidney encapsulated?
yes
What is in the cortex of the kidney?
renal corpuscles or glomeruli
cortical labyrinth and medullary rays
How many medullary rays are then in a human kidney?
400-500
What do medullary rays look like?
almost like the splenic cords, long and dark and longitduinal
What do cortical labyrinths look like?
like swirlies filled with corpuscles
How many renal lobes/pyramids of the medulla are there?
15-20
What does the base of a renal pyramid form?
the corticomedullary border
What is the rounded off end of a renal pyramid?
a renal papilla
Renal papilla drain up to (blank) collecting ducts/ducts of bellin
20
What does a kidney lobe refer to?
medullary pyramid + overlying cortex
What does a kidney lobULE refer to?
a group of nephrons that open into branches of the same main collecting duct…. space between 2 interlobular arteries
How does the kidney regulate hematopoiesis?
secretion of erythropoieten
Where are the renal corpuscles and glomeruli found?
CORTEX!
What does the nephron consist of?
Renal corpuscle (glomerulus) and kidney tubules (PCT, Loop of Henle, DCT)
Each kidney has more than (blank) nephrons
1 million!
What happens in the nephron?
filtration , excrection and reabsorption
What is a uriniferous tubule?
nephron plus colleting duct
The end of renal papilla resemble a strainer and is called (blank)
area cribosa
What does a renal corpuscle consist of?
Bowmans capsule and glomerulus
What do arcuate vessels do?
separate cortex from medulla
The renal corpuscle of each (blank) nephron is located in the outer region of the cortex. Its loop of Henle is short and does not enter the medulla. The efferent glomerular arteriole branches into a peritubular capillary network, surrounding the convoluted segments of its own and adjacent nephrons.
Cortical nephron
The renal corpuscle of each (blank) nephron is located in the cortex region adjacent to the medulla. Its loop of Henle is longer and extends deep into the medulla. The efferent glomerular arteriole branches into vascular loops called the vasa recta. The vasa recta descend into th emedulla and form a capillary network surrouding the collecting ducts and limbs of the loop of Henle.
Juxtamedullary nephron
Where type of nephron is the majority of nephrons?
cortical nephrons
What are the two types of nephrons?
Do they vary in there thick and thinness
cortical and juxtamedullary
yes
Does the vasa recta come off the peritubular capillary or the efferent arterioles?
peritubular capillary
Describe the flow of vascularization in the kidney.
Blood enters via the interlobar artery->arcuate artery-> interlobular artery->afferent, glomerulus, efferent-> paratubular or vasa recta->interlobular vein->arcuate vein->interlobar vein
What gives rise to arcuate arteries?
interlobar arteries
afferent glomerular arterioles derive from an (blank)
interlobular artery
Efferent glomerular arterioles close to the subscapular region give rise to the (blank)
peritubular capillary network
Effernt glomerular arterioles close to the juxtamedullary region give rise to the (blank)
vasa recta
The arterial blood supply to the cortex is (blank)
terminal (no anastomoses)
In the kidney, an arteriole is interposed between (blank) capillary networks.
2
An afferent arteriole gives rise to a mass of capillaries called the (blank). These capillaries coalesce to form an (blank), which gives rise to capillary networks (peritubular capillary network and the vasa recta) surrounding the nephron
glomerulus
efferent
In the liver and the hypohphysis,veins feed into an extensive capillary or sinusoid network draining into a vein. This distribution is called the (Blank) system.
venous portal system
The glomerular tuft in the kidney is also called the (blank)
arterial portal system
Where is the venous portal system found?
liver and pituitary
When you leave the efferent arteriole where do you go?
to the paratubular network or the vasa recta
The renal glomerulus is also called the (blank)
corpuscle
(blank) capillaries grow into blind end of nephron.
tuft of glomeruluar capillaries
(blank) always bulge into the urinary space. They are components of the visceral layer of the capsule of Bowman.
podocytes
(blank) cells cover the parietal layer of the capsule of Bowman.
squamos epithelium (mesothelium)
What are the two basement membranes of the corpuscle?
BM of capsule of Bowman
BM of glomerular
Glomerular capillary lined by (blank).
fenestrated endothelial cells
The (blank) consists of mesangial cells embedded in the mesangial matrix.
mesangium
(blank) secrete extracellular matrix, prostaglandins, and cytokines and have phagocytic activity. The can contract and regulate glomerular filtration by controlling blood flow through glomerular capillaries.
Mesangial cells
(blank) reach the afferent arteriole and innervate juxtaglomerular cells. An increase in sympathetic activity stimulates renin secretion.
Sympathetic nerve fibers
Sympathetic nerve fibers reach the (blank) and innervated (blank).
affarent arteriole
juxtaglomerular cells
The (blank) is a distinct epithelial region found at the thick ascending limb-distal convoluted tubule junction. .
macula densa
The (blank) faces the triangular area formed by the afferent and efferent arterioles of the same nephron.
macula densa
The cells of the macula densa are in contact with (blank) .
extraglomerular mesangial cells
What is the glomerular capillaries covered by?
What does this covering function in?
- visceral epithelium (podocytes)
- production of glomerular filtrate and supportive mesangial cells
The glomerular filtrate is released into the (blank)
urinary space
The urinary pole is continuous with the (blank)
proximal convoluted tubule
The juxtaglomerular apparatus is located at the (blank)
vascular pole
(blank) is located in the juxtaglomerular apparatus and is an area of specialized cells within the DCT that is in contact with both the afferent and efferent arterioles.
macula densa
(blank) is located in the juxtaglomerular apparatus and is found between the afferent and efferent arterioles.
extraglomerular mesangial cells
(blank) possess modified smooth muscle cells in the tunica media called juxtaglomerular cells
afferent and efferent arterioles
What are the components of the juxtaglomerular apparatus?
macula dense, extraglomerular mesangial cells, JG cells
The vascular pole and the urinary pole are (blank) degrees from each other.
180 degrees
There are 2 walls to glomerulus, what are they?
visceral and parietal
Visceral walls of the glomerulus are made up of (blank) that cover OVER capillaries.
podocytes
The parietal wall is also called the (blank) and it is lined with (blank)
bowmen’s capsule
simple squamos epithelium (mesothelium)
In between the visceral and parietal layer is the (blank)
urinary space
what do juxtaglomerular cells make?
renin
The glomerulus has a (blank) capillary epithelium.
fenestrated
The basal lamina of the glomerulus is made up of what?
podocyte and capillary basal lamina
What are the three layers of the basal lamina of the glomerulus?
1) lamina rara intern (capillary side)
2) lamina densa (thick)
3) lamina rara externa (visceral layer side)
What is the capillary side of the basal lamina?
lamina rara interna
What is the very thick layer of the basal lamina?
lamina densa
What is the visceral layer of the basal lamina?
lamina rara externa
What is the visceral layer of the Bowman’s capsule made of?
podocytes and pedicles
What is the primary process of the visceral layer of the bowman’s capsule? What is the secondary?
podocytes
pedicels
What lie on the lamina rara externa and interdigitate forming up filtration slits covered by a thin (6 nm thick) slit diaphragm?
pedicels
What is the connective tissue component of glomerulus?
mesangial cells
What are the mesangial cells derived from?
mesoderm
What are cells of the glomerulus that are phagocytic and responsible for resorption of the basal lamina?
mesangial cells
What cells are contractile, capable of proliferation, synthesize both matrix and collagen, secrete prostaglandins and endothelins, provide physical support, controls turnover of basal lamina by phagocytic activity, regulates blood flow by contractile activity?
mesangial cells
What do mesangial cells secrete and synthesize?
Prostaglandins and endothelins
matrix and collagen
Fluid leaving the glomerular capillaries through the fenestrae is filtered by the (blank).
basal lamina
The (blank) traps larger molecules( >69,000 Da). (blank) impede the passage of negatively charged molecules and molecules that are incapable of deformation.
lamina densa
laminae rara
The fluid that penetrates the lamina densa and enters Bowman’s space, is the (blank)
glomerular ultrafiltrate.
Because the basal lamina traps larger macromolecules, it would become clogged were it not continuously phagocytosed by(blank) and replenished by both the visceral layer of Bowman’s capsule (podocytes) and glomerular endothelial cells.
intraglomerular mesangial cells
Inside the capillary you will find (blank) capillary endothelium
fenestrated
The basal lamina of the endothelia cells fuses with (blank)
podocytes
The capillary fused basal lamina is where we have (blank)
selective filtration
The visceral layer of bowmen’s capsule is made up of (blank) that have lots of extensions coming off of them called (blank). Coming off of the primary processes are (blank)
podocytes primary processes secondary processes (pedicels)
These pedicels interdigitate, which will form up with filtration slits that are covered by (Blank)
thin slit diaphragm.
These pedicels interdigitate, which will form up with (blank) that are covered by thin slit diaphragm.
filtration slits
The (blank) that allow us to continually filter our blood and form urine because it is them that keep the filitration membrane CLEAN!
mesangial cells
The endothelium of the glomerular capillaries is fenestrated and permeable to water, sodium, urea, glucose and small proteins. Endothelial cells are coated by (blank) (heparan sulfate) which slows down the filtration of large anionic proteins. Therefore what pass through the glomerular capillaries?
negatively charged glycoproteins
postively charged ions
The basal lamina, a produce of endothelial cells and podocytes, contains (blank)
type IV collagen, laminin, fibronectin, and proteoglycans rich in the GAG heparan sulfate- which also slows down the filtration of anionic proteins.
The space between adjacent pedicels is called the (blank). A filtration slit diaphragm (blank) adjacent pedicels.
filtration slit
links
The diaphragm consists of (blank), a cell adhesion molecule of the immunoglobulin superfamily, anchored by the proteins CD2AP to actin filaments within the pedicel. A mutation of the gene encoding nephrin causes (blank) , characterized by massive proteinuria (leakage of albumin in urine) and edema.
nephrin
congenital nephrotic syndrome
What is the proximal convoluted tubule made out of?
simple cuboidal epithelium
What is eosinophilic, has simple cuboidal epithelium, has an evident striated border (microvilli), where Na, Cl, H20, glucose, AA, and proteins are resorbed. Organic solutes, drugs and toxins are eliminated here.
Proximal Convoluted Tubule
What is eosinphilic?
PCT
What has an evident striated border (microvilli)?
PCT
Where is Na, Cl, H20, glucose, AA, and proteins are resorbed. Organic solutes, drugs and toxins are eliminated here.
PCT
How many regions are there in the thin loops of henle? What are they? What are they lined with?
Three
Descending thin limb, Henle’s loop, ascending thin limb
Squamos epithelium
What are often difficult to distinguish from capillaries, with a descending loop permeable to H20 and an ascending loop slightly permeable to H20.
thin loops of henle
What has macula densa, is sensitive to aldosterone levels and has K and Hydrogen ions secreted into the lumen controlling K extracellular levels and acidity of urine.
Distal convoluted tubule
What monitors filtrate for Na and Cl as part of the JGA apparatus and is made up of tall and narrow cells?
DCT
(blank) -> have microvilli, are red, have simple cuboidal epithelium (has fuzzy irregular lumen) . There is a thick and thin portion of this tubule. i.e. regional differences that are (blank) NOT structural. Thin loops of henle are difficult to tell apart from capillaries.
(blank) -> smooth regular lumen : )
Proximal convoluted tubule
physiological differences
Distal convulued tubule
The (blank) reabsorbs about 70% of filtered water. The osmotic gradient established by reabsorbed glucose and NaCl is the driving force for (blank) across tight junctions and the proximal tubular cells.
Proximal convoluted tubule
water reabsorption
a (blank) mechanism enables the reabsorption of the NaCl. The distal tubule is impermeable to water.
Symport mechanism
Is the distal tubule impermeable to water?
yes
(blank) have short microvilli and abundant basal mitochondria. Lysosomes and tubulovesicular structures are not prominant.
Distal convoluted tubular cells
How can you tell PCTs from DCTs?
PCTs have abundant lysosomes that are stained dark and the apical domain of PCT have prominent brush border (microvilli) and vesicles.
Cells lining the PCTs and DCTs contain abundant basically located (blank).
mitochondria
What are the three components of JGA?
macula densa of DCT
Juxtaglomerular cells of afferent (occasionally efferent arterioles)
extraglomerular mesangial cells
What are modified smooth muscle cells of tunica media and produce renin (angiotensin-converting enzyme (ACE), angiotensin I and II)?
Juxtaglomerular cells
cells of the (blank) and JG cells communicate.
macula densa
What are connected to each other and to JG cells by gap junctions. Angiotension II causes contraction of these cells.
Extraglomerular cells
WHere do you have the specialized cells (the juxtaglomerular cells) that release the renin?
ONLY at the juxtaglomeruluar apparatus
The extraglomerular mesangial cells form junctional complexes with each other through (blank).
gap junctions.
(blank) senses NA and Cl and will communicate with epithelium cells of arteriole to cause vasoconstriction.
Macula densa
(blank) are predominant in the afferent arteriole of the glomerulus.
juxtaglomerular cells
(blank) are modified smooth muscle cells producing the enzyme renin.
JG cells
Together with extraglomerular mesangial cells and the macula densa of the distal convoluted tubule, it is part of the juxtaglomerular apparatus.
JG cells
(blank) are innervated by sympathetic nerve fibers Renin secretion is enhanced by norepinephrine and dopamine secreted by adrenergic nerve fibers.
JG cells
Collecting Tubule/Duct is lined by 2 types of cuboidal epithelium, what are they?
principal cells and intercalated cells
What kind of cells line the collecting Tubule/Duct?
cuboidal epithelium
How do principal cells of the collecting duct work?
- they allow H20 resorption in presence of ADH
- In the Presence of ADH, urine volume is low and concentrated
How do intercalated cells of the collecting duct work?
acidifies urine, resorbing K+ and secreting HCO3-
What have distinct lateral cell borders and are found mostly in medullary rays and medulla?
intercalated cells of the collecting tubule/duct
Which cells of the collecting tubule are dark? and which are light?
Dark cell=intercalated cells
Light cell= prinicipal cell
What is the role of renin in blood pressure regulation if you have decrease in blood pressure?
decrease in blood pressure-> reduced stretch in afferent arteriole and reduced Na and Cl in filtrate acts on macula Densa-> communicates to JG cells-> JG cells release renin-> causes arteriole constrction and increase in aldosterone-> increase renal retention of Na and H20 raising blood volume-> restores blood pressure.
The thick ascending distal convoluted tubule is lined with (blank)
cuboidal cells
The thin ascending and descending segments of loop of henle is made of (blank).
squamos cells
What kind of cells line the collecting tubule/duct?
cuboidal epithelium
What is the proximal thick convoluted tubule made out of?
simple cuboidal epithelium with brush border
As you approach the cribosa (end of the renal papilla) the cuboidal cells turn into (blank)
tall columnar cells
What are large, combination of several cortical collecting tubules.?
medullary collecting tubules
How does urine pass to the ureter?
collecting tubules-> medullary collecting tubules-> papillary collecting tubules (main collecting ducts)->minor calyx-> major calyx-> renal pelvis
Does the ureter have a submucosa?
NO
What are the components of the ureter?
mucosa, muscularis externa, adventitia
What kind of cells line the mucosa of the ureter?
transitional epithelium
What is made up of
- stellate lumen lined by transitional epithelium
- fibroelastic lamina propria
- no mucosal or submucosal glands
- no muscularis mucosae
Mucosa of Ureter
What makes up the layers of the Muscularis Externa,in the ureter?
-two layers in the upper
2/3 ILOC
-three layers in lower
1/3 IL MC OL
Each ureter takes an (blank) course through the bladder wall, closing the lumen when the bladder
becomes distended
oblique course
What are the layers of the urinary bladder?
transitional epithelium->lamina propria-> muscle layers-> adventitia or serosa
What are domed shaped cells?
transitional epithelium
From the outside in name the layers of the ureter;
adventitia->muscle externis-> lamina propria (mucosa)-> transitional epithelium (mucosa) (urothelium)
What are the components of urinary bladder?
1) Mucosa
- transitional epithelium
- fibroelastic lamina propria
(2) Muscularis
- IL MC OL
(3) Adventitia
- fibroelastic adventitia is covered superiorly by peritoneum, forming a serosa
Superior surface of epithelium of the bladder is covered in (blank). The transitional epithelium of the bladder is also called (blank)
serosa
uroepithelium
(blank) generate a thickened domain able to adjust to large changes in surface area of the bladder.
apical plaques
What does this describe?
-transitional near the bladder, transitions
to a pseudostratified and stratified
columnar to a stratified squamous, non-
keratinized at the distal end
Mucosa of the female urethra
What is the male prostatic urethra lined with?
transitional epithelium
What is the male membranous urethra lined with?
pseudostratified and stratified
columnar
What is the penile urethra made out of?
pseudostratified and stratified
columnar transitions to stratified
squamous non-keratinizing
What do the male and female urethra have in common?
Mucosa
- vascular fibroelastic lamina propria - urethral glands (glands of Littre in male)
Muscularis
-internal sphincter ILOC (Inter longitudinal, outer circular)
-at UG diaphragm picks up sphincter of
skeletal muscle permitting voluntary
control
In females the length of the urinary tract and the (blank) distance between the urethral opening and anus means that there is less of a distance for bacteria and other pathogens to travel before reaching the bladder. This may be one of the contributing factors to the high rate of urinary tract infections in females, when compared to males.
short
Urethral glands help lubricate the (blank) so they don’t get stuck shut.
Internal sphincter is (blank) while external sphincter is (blank).
urethral epithelium
involuntary
voluntary
