Kidney embryology Flashcards
What two ductal structures develop in both male and female embryo
Wolffian/ Mesonephric ducts
Paramesonephric/ Mullerian ducts
Where does mesenchyme run on the embryo
On either side of the embryo
How do the ducts behave in female embryos
Mesonephric duct degenerates apart from lower portion which forms uteric bud
Paramesonerphic duct forms oviduct
How do ducts behave in male embryo
Mesenophric duct forms the male reproductive truct and uteric bud
Paramesonephric duct degenerates
How many kidney develop in the embryo
3
What is the final, fully developed kidney called
Metanephric kidney
What kidney do you start off with embryo-logically
Pronephric kidney
Which two embryological kidneys form a duct system
Pronephric
Mesonephric
Where are all 3 embryological kidneys formed from
Mesonephric duct
What 2 embryonic structures is the metanephric kidney derived from?
Uteric bud from mesonephric duct
Metanephric bud derived from mesenchyme
What is the site called where uteric bud comes into contact with mesenchyme
Metanephric bud
What is derived from the uteric bud?
- Uterer
- Renal pelvis
- Major and minor calices
- Collecting tubules
What is derived from metanephric bud
- Glomerulus and capillaries
- Bowmans capsule
- PCT
- Loop of henle
- DCT
How many collecting tubules are found in kidney
1-3 million
What do the major calyces bifurcate to form
Minor calyces
What do minor calyces split to form
Collecting tubules
What happens when mesenchyme comes into contact with the collecting tubule
It elongates
What happens once the kidney has formed
It ascends within the embryo
What happens as kidney grows and enlarges
It open out and moves upwards within embryo until it reaches final resting region
Where does metanephros develop
S1
What is final location of kidney
Upper lumbar region
What is failure for kidney to ascend known as
Ectopic kidney
What happens to renal arteries as kidneys ascend
- Existing renal arteries degenerate in sacral region
- As kidney moves upwards new renal arteries form
When does kidney in embryo become functional
End of first trimester
What happens to urine in embryo
Urine passed into amniotic cavity mixes with fluid
Swallowed by foetus
Passes through kidney and back into amniotic fluid
What organ performs excretory functions in utero
Placenta (not kidney)
Define kidney agenesis
Failure of kidney to form, often associated with uteric bud formation
Is kidney agenesis common or rare
Fairly common (1 in 1000)
What is bilateral agenesis
When both kidney fail to develop
Can the baby survive after birth if it has bilateral agenesis
no
What usually causes bilateral agenesis
Failure of uteric bud to form on both sides
How many babies are born with bilateral agenesis
1 in 10,000
As well as not having a kidneys, what other defects are associated with bilateral agenesis
Failure of lungs and club foot because no kidneys to produce amniotic fluid in the womb
What is bifid ureter
Ureter splits in two
What can be formed from bifid ureter
One large kidney with 2 ureters or two completely separate ureters
Incidence of bifid ureters?
2%
Does bifid ureter impact on kidney function
No
What is ectopic-pelvic kidney
One kidney remains in pelvic, but still functional
What is horseshoe kidney
Kidneys fuse in pelvic region forming a single U shaped kidney.
Why can’t horseshoe kidneys rise?
Due to position of inferior mesenteric artery
Does horseshoe kidney function normally
Yes
Incidence of ectopic kidney?
1 in 500 to 1 in 1290
What % of ectopic kidneys are never detected
50
What is polycystic kidney
Kidney develops fluid filled cysts
What % of polycystic kidney patients have kidney failure by age 60
50
How many people have autosomal dominant polycystic kidney
1: 1000
How many people have autosomal recessive polycystic kidney
1: 20,000
What % of mutations causing polycystic kidneys occur in polycystin/ PKD-1
85-90
If the mutation of polycytic kidneys isn’t in PKD-1, what is it?
Polycystin-2/ PKD-2
Define primary cillia
Single sensory cilia on a cell
Describe the sequence by which the cyst on the kidneys in polycystic kidney grows
- Cyst originates as dilations of intact tubule
- Cyst enlarges and loses contact with nephron
- Epithelium becomes secretory resulting in increased fluid secretion into lumen of cyst
- Increased proliferation of cyst epithelium
