Urogenital System Part A Flashcards
Label the urinary system
Label the kidney
The functional unit of the kidney is the ______
The functional unit of the kidney is the nephron
Label the nephron
Why are the kidneys on the posterior abdominal wall?
Because the tissue the they came from: Intermediate mesoderm
Label the diagram;
Which part of the diagram shows the tissue from which the kidneys originate
Following folding, the intermediate mesoderm sits immediately posterior to the ________ on either side of the _______
Following folding, the intermediate mesoderm sits immediately posterior to the intraembryonic coleom on either side of the dorsal aorta
Intermediate mesoderm: blobs of ______ between _____ and ______
Intermediate mesoderm: blobs of mesoderm between somites and lateral plate mesoderm
Mystery diagnosis
Oligohydramnios
- Not enough amniotic fluid because kidneys didn’t form (or in some cases, could be because of a blockage)
Function of urinary system:
Prenatally:
Postnatally:
- Prenatally:
- urinary system produces amniotic fluid
- Postnatally
- Urinary system functions to excrete wastes and maintain electrolyte balance
What is oligohydramnios?
Lack of amniotic fluid → can impair growth and cause lung problems (potter sequence)
What are the three types of kidney throughout evolution?
-
Pronephros
- often one nephron
- no integrated glomerulus
- filters fluid from body cavity
-
Mesonephros
- multiple nephrons
- filter blood directly (integration between blood and kidney)
-
Metanephros
- many nephrons
- filter blood directly and concentrate urine
Pronephros vs Mesonephros
- In pronephros, blood is filtered into the body cavity (coelom)
- In mesonephros, the glomerulus is integrated into nephron and blood is filtered directly
Which of the three types of kidneys are present during development?
- Mesonephros - temporary kidney
- Metanephros - definitive kidney
Mesonephros:
- Mesonephroi start to form in week ____
- Each mesonephros consists of a _______, a series of ______ and ________
Mesonephros:
- Mesonephroi start to form in week four (4)
- Each mesonephros consists of a mesonephric duct, a series of mesonephric tubules and associated capillaries
The mesonephric tubules form in a _______ sequence
The mesonephric tubules form in a cranial to caudal sequence
Mesonephric duct extends _______ and fuses with the ______ in the ____ week
Mesonephric duct extends caudally and fuses with the urogenital sinus in the 5th week
- At first, the cranial margin of the mesonephros is at the _______
- By 6 weeks, there is _______ and the cranial margin reaches the ______ vertebra
- At first, the cranial margin of the mesonephros is at the 10th somite, or what will be the C7/T1 vertebral level
- By 6 weeks, there is degeneration of early tubules and the cranial margin reaches the T5 vertebra only vertebra
Mesonephroi function as temporary kidneys from weeks _____
Mesonephroi function as temporary kidneys from weeks 6-10
Mesonephric tubules are induced by the ______ to form within the _______
Mesonephric tubules are induced by the mesonephric duct to form within the adjacent intermediate mesoderm (MET)
Label
Label
35-38 days what is happening at the urogenital sinus?
Mesonephric ducts are fusing with urogenital sinus
Further division of the cloaca
Mesonephric ducts fuses with ______ of ______
Mesonephric ducts fuses with posterolateral walls of urogenital sinus
Cloacal membrane breaks down in ____ week when contacted by _____
Cloacal membrane breaks down in 7th week week when contacted by urorectal septum
Label
The mesonephric duct induces ______ in the ______ to become ______ and form ______
The mesonephric duct induces mesenchyme in the adjacent intermediate mesoderm to become epithelial and form a vesicle (MET)
Label
The mesonephric duct induces mesenchyme in the adjacent __________ to become epithelial and form a ______
Steps of Mesonephric development:
- The mesonephric duct induces _______ in the adjacent intermediate _______ to become _______ and form a _______.
- The _______ elongates to form a tubule and then fuses with the _______ (leads to developing bladder)
- The _______ sends off a branch, which forms a tuft of capillaries adjacent to the mesonephric tubule
- the _______ end of the mesonephric tubule curves around the _______ to form the _______; the lumen of the tubule becomes continuous with the _______
- The mesonephric duct induces mesenchyme in the adjacent intermediate mesoderm to become epithelial and form a vesicle.
- The mesonephric vesicle elongates to form a tubule and then fuses with the mesonephric duct (leads to developing bladder)
- The dorsal aorta sends off a branch, which forms a tuft of capillaries adjacent to the mesonephric tubule
- the medial end of the mesonephric tubule curves around the glomerulus to form the bowmans capsule; the lumen of the tubule becomes continuous with the mesonephric duct
The _______ _____ elongates to form a tubule and then fuses with the _____ (leads to developing bladder)
The mesonephric vesicle elongates to form a tubule and then fuses with the mesonephric duct (leads to developing bladder)
The _______ sends off a branch, which forms a tuft of capillaries adjacent to the _________
The dorsal aorta sends off a branch, which forms a tuft of capillaries adjacent to the mesonephric tubule
the medial end of the mesonephric tubule curves around the ______ to form the ______; the lumen of the tubule becomes continuous with the _______
the medial end of the mesonephric tubule curves around the glomerulus to form the bowmans capsule; the lumen of the tubule becomes continuous with the mesonephric duct
The metanephros is entirely formed by _______ from _____ and ______
The metanephros is entirely formed by intermediate mesoderm from caudal (distal) mesonephric duct and mesenchyme in intermediate mesoderm adjacent to ureteric bud
label
The metanephros develops from which 2 sources?
-
Ureteric bud:
- branches off caudal mesonephric duct (sacral region)
- Forms the collecting duct system of the kidney
-
Metanephric blastema
- Develops from mesenchyme in intermediate mesoderm adjacent to the ureteric bud
- Forms the nephrons of the kidney
Label the image:
C is the ______ that develops into the ______
D is the _____ that develops to form the _______
Label the image:
C is the Ureteric bud that develops into the collecting duct system of the kidney
D is the metanephric blastema that develops to form the nephrons of the kidney
The expanded end of the ureteric bud is called the _______ and grows into the _______
The expanded end of the ureteric bud is called the ampulla and grows into the metanephric blastema
What might be the reason for the “mystery diagnosis” pictured?
- If either ureteric bud OR metanephric blastema fail to form = No kidney is made
Label the image:
The ureteric bud _____ by middle of 6th week in response to _______
Each ampulla acquires a _________, creates lobulated appearance of early kidney
The ureteric bud bifurcates by middle of 6th week in response to signals from the metanephric blastema
Each ampulla acquires a mesenchymal cap of blastemal cells, creates lobulated appearance of early kidney
Branching of ureteric bud:
- Once the ureteric bud enters the metanephric blastema, it undergoes multiple rounds of branching to form the _________
- A few weeks later, _______ start to form alongside the still growing and branching ureteric bud
Branching of ureteric bud:
- Once the ureteric bud enters the metanephric blastema, it undergoes multiple rounds of branching to form the proximal portions of the collecting duct system
- A few weeks later, nephrons start to form alongside the still growing and branching ureteric bud
Label the image
Label the image
Each ampulla acquires a ________ which are the nephron progenitors
Each ampulla acquires a condensation of mesenchymal cells (blastemal cap) which are the nephron progenitors
Each ampulla acquires a condensation of mesenchymal cells (blastemal cap) which are the ________ progenitors
Each ampulla acquires a condensation of mesenchymal cells (blastemal cap) which are the nephron progenitors
Renal vesicle formation:
Some blastemal cap cells undergo ______ to assemble into renal vesicles in the armpits of ________
Renal vesicle formation:
Some blastemal cap cells undergo Mesenchymal to epithelial transition (MET) to assemble into renal vesicles in the armpits of T-shaped ureteric branch tips
Some blastemal cap cells undergo Mesenchymal to epithelial transition (MET) to assemble into ________ in the armpits of T-shaped ureteric branch tips
Renal vesicle formation:
Some blastemal cap cells undergo Mesenchymal to epithelial transition (MET) to assemble into _renal vesicle_s in the armpits of T-shaped ureteric branch tips
Nephron development:
- Renal vesicles start to form in the ___ week
- Renal vesicle ________
- As it grows, the developing ______ connects to the side of the ureteric branch
Nephron development:
- Renal vesicles start to form in the 8th week
- Renal vesicle elongates and bends (comma-shaped body to “s-shaped body” to mature nephron)
- As it grows, the developing nephron connects to the side of the ureteric branch
- _______ occurs early
- Right from the start, parts of the ______ are specified to form different regions of mature nephron, and so they express different genes
- regional specification occurs early
- Right from the start, parts of the nephric vesicle are specified to form different regions of mature nephron, and so they express different genes
The _______ continues to grow and branch as the nephrons are forming
End up with arcades of nephrons attached to the _______
The ureteric bud continues to grow and branch as the nephrons are forming
End up with arcades of nephrons attached to the collecting ducts
The _______ continues to grow and branch as the nephrons are forming
End up with arcades of nephrons attached to the _______
The ureteric bud continues to grow and branch as the nephrons are forming
End up with arcades of nephrons attached to the collecting ducts
When does nephrogenesis finish?
Nephrogenesis is finished shortly before birth
Branching of the ureteric bud changes over time:
- The early branches expand/remodel to make the _______
- Late branches form _______ which elongate and bundle into the _______
Branching of the ureteric bud changes over time:
- The early branches expand/remodel to make the renal pelvis and calyces
- Late branches form collecting ducts which elongate and bundle into the renal pyramids
What is the change seen in the image?
- position of metanephros relative to mesonephros
- Ureter now attaches directly to the bladder (no longer a branch of mesonephric duct)
Kidneys “ascend” due to:
Kidneys are initially close to ____ but move _____ during ascent
Ureters elongate and kidneys are displaced ______ until come to sit under _____ (in upper lumbar region) in 9th week
Kidneys “ascend” due to: differential body growth (not active migration)
Kidneys are initially close to midline but move further apart during ascent
Ureters elongate and kidneys are displaced cranially until come to sit under adrenal glands (in upper lumbar region) in 9th week
Renal artery remodeling:
- The renal artery is initially a branch off the _______
- As kidney ascends, blood supply changes to branches off the ______ at increasingly ______ locations
Renal artery remodeling:
- The renal artery is initially a branch off the common iliac artery
- As kidney ascends, blood supply changes to branches off the descending aorta at increasingly cranial locations
What happens if arteries to the ascending kidney fail to regress?
Accessory renal arteries
may obstruct the ureter in some cases
Increase in kidney size after birth results mainly from growth of the _______ and ______
Increase in kidney size after birth results mainly from growth of the proximal convoluted tubules (PCT)s and interstitial tissue
The bladder forms from the expanded part of the _______
The bladder forms from the expanded part of the urogenital sinus
A: _______ which develops into the ______
B: ______: develops into the _______
C: ______: contributes to the _______
A: Bladder segment which develops into the bladder
B: Pelvic segment: develops into the pelvic urethra
C: phallic segment: contributes to the penile urethra (males) and vestibule of vagina (females)
- Mesonephroi produce urine from weeks ______
- _______ breaks down in 7th week
- Initially urine can leave through _____ but will soon be excreted into the ______
- Allantois then solidifies into a _______
- Mesonephroi produce urine from weeks 6-10
- Cloacal membrane breaks down in 7th week
- Initially urine can leave through allantois (leads to umbilical cord) but will soon be excreted into the amniotic cavity
- Allantois then solidifies into a ligament (urachus/median umbilical ligament)
What is a urachal fistula?
fistula = abnormal connection
Urachal fistula occurs when the allantois is maintained (fails to solidify into ligament)
Urine leaks out
Urachal abnormalities:
- If epithelial tube of allantois fails to completely degenerate into a _______ may be left with a _______
- Cysts are only significant if _____
- typically show up as a _______ near _____
- Urachal fistulas are unusual and typically appear only when ______
Urachal abnormalities:
- If epithelial tube of allantois fails to completely degenerate into a fibrous cord may be left with a urachal cyst or fistula
- Cysts are only significant if become infected
- typically show up as a sore mass near umbilicus
- Urachal fistulas are unusual and typically appear only when urethra is blocked
- Initially, ureter forms as a branch off ________
- By this stage the ureters are separate from _______ and both are connected to the _________ of the ____
- Initially, ureter forms as a branch off mesonephric duct
- By this stage the ureters are separate from mesonephric ducts and both are connected to the posterior wall of the bladder
- Ureteric buds and mesonephric ducts must separate so _________
- Largely driven by ______ of ______
- _______ move inferiorly
- Ureteric buds and mesonephric ducts must separate so ureters connect directly to the bladder (ureterovesical junction)
- Largely driven by apoptosis of common nephric duct
- Mesonephric ducts move inferiorly
What is the fate of the mesonephric duct?
- Males:
- Vas deferens
- Females
- Degenerates
Ureters connect at ______ on posterior wall of bladder
Ureters connect at apices of trigone of bladder on posterior wall of bladder
