Renal Embryology

Question 1

What gives rise to the kidneys and genitalia

Answer 1

Intermediate mesoderm

Question 2

What specifically gives rise to the nephron

Answer 2

The mesonephric tube

Question 3

What are the three kidneys in order of development

Answer 3

Pronephros 
Mesonephros (functional)
Metanephros (definitive/true)

Question 4

When does the pronephros form and degenerate

Answer 4

Forms and degenerates in the 4th week

Question 5

Where does the pronephros form

Answer 5

In the cervical region of the embryo and heads to the cloaca

Question 6

When does the mesonephros appear and when it is functional until

Answer 6

Appears in late 4th week and is functional until 11 - 12 weeks

Question 7

What does the mesonephros ultimately become

Answer 7

The male genitalia

Question 8

When does the metanephros form

Answer 8

Week 5

Question 9

What are the two parts of the metanephros

Answer 9

Ureteric bud

Aka: metanephric duct aka metanephric diverticulum

Metanephrogenic blastema (mass)

Question 10

What does the glomeruli arise from

Answer 10

The dorsal aorta

Question 11

Bowman’s capsule and the mesonephric tubules arise from what

Answer 11

Intermediate mesoderm

Question 12

The mesonephric duct induces what

Answer 12

mesonephric Nephrons to form in the adjacent nephogenic cord

Question 13

The ureteric bud is an outgrowth of what

Answer 13

The mesonephric duct

Question 14

What is the metanephric blastema derived from

Answer 14

The nephrogenic cord

Question 15

What does the ureteric bud give rise to

Answer 15

The ureter
Renal pelvis
Major and minor calyces
Collecting tubules

Question 16

What does the metanephric blastema GRT

Answer 16

Renal vesicles
Bowman’s capsule
PCT/DCT
LoH

Question 17

The ureteric bud contacts the metanephric blastema and gives rise to what first

Answer 17

The renal pelvis

Question 18

What does the ureteric bud GRT second and third

Answer 18

Major and then minor calyces

Question 19

What does the metanephros nephron originate as

Answer 19

A vesicle within the blastemic cap surrounding the ampulla of the collecting duct

Question 20

What is the role of the formation of the collecting ducts

Answer 20

When these are formed from the ureteric bud, it causes a signal to be sent to the metanephros blastema to begin production of the nephron and rest of the kidney system

Question 21

Who does unilateral renal agenesis usually affect? And what is presented

Answer 21

Usually affects males

Usually no L kidney

Question 22

What happens in bilateral renal agenesis? What causes this

Answer 22

No kidneys

Usually caused by oligohydramnios

Question 23

What does a duplex kidney result from

Answer 23

Abnormal division of the ureteric bud

Question 24

When are the kidneys positioned by in adults

Answer 24

Week 9

Question 25

What causes the kidneys to ascend in the fetus

Answer 25

The caudal growth of the embryo

Question 26

During the ascent, kidneys do what? What does this allow for

Answer 26

Rotate 90 degrees. This allows for the hilum to be facing the Ao.

Question 27

What causes a pelvic (ectopic) kidney

Answer 27

Results from the lattice of vessels from the posterior cardinal V. Blocking the ascent

Question 28

What causes a horseshoe kidney

Answer 28

The inferior poles of the kidney are fused, and thus the kidney is unable to get pass the IMA and stays at L3

Question 29

Define autosomal recessive polycystic kidney disease

Answer 29

Occurs due to a mutation of the PKHD1 gene Both kidneys have small cysts Renal insufficiency results from this Can be associated with pulmonary hypoplasia/oligohydramnios

Question 30

Define multicystic dysplastic kidney disease

Answer 30

Abnormal development of the renal system The cysts are a dilatation of the LoH, this could be an issue with the metanepheros blastema

Question 31

In the adult, the ureter only arises from what

Answer 31

The metanephric duct (ureteric bud)

Question 32

The bladder is formed from what

Answer 32

Hindgut Endoderm

Question 33

What is the trigone and what is it formed from

Answer 33

Is the incorporation of the mesonephric duct into the bladder wall Comes from mesoderm

Question 34

What makes up the urogenital and anal membrane

Answer 34

Endo/ecto -derm

Question 35

What separates the urogenital membrane from the anal membrane

Answer 35

The uro-rectal septum

Question 36

Define the allantois and what does it GRT

Answer 36

This is an extension of the hindgut endoderm into the bladder Gives rise to the urachus and the median umbilical L.

Question 37

What specifically gives rise to the bladder (within hindgut endoderm)

Answer 37

The vesicle part of the urogenital sinus

Question 38

What does the pelvis part of the urogenital sinus GRT

Answer 38

``` Urethra (f) Prostatic urethra (m) ```

Question 39

What does the phallic part of the urogenital sinus GRT

Answer 39

Lining of the vaginal vestibule (f) Spongy urethra (m)

Question 40

When does exstrophy of the bladder occur?

Answer 40

During body folding of the 4th week

Question 41

What causes exstrophy of the bladder

Answer 41

Defective closure of the ventral abdominal wall due to the mesoderm not migrating between the endo/ecto -derm on the anterior body wall

Question 42

What is the chromaffin system formed from

Answer 42

NC Cells

Question 43

What is the surarenal caspule formed from

Answer 43

Meonephric mesoderm

Question 44

How does the cortex of the AG form

Answer 44

Comes from the coelomic epithelium of the somatic mesoderm in the 6th week. First wave makes the fetal cortex Second wave makes the adult cortex