Kidney and urogenital

Question 1

What mesoderm does the urogenital system originate from?

Answer 1

Intermediate mesoderm

Question 2

How many kidney systems develop in the embryo?

Answer 2

3

Question 3

What are the names of the three primitive kidney systems rostral to caudal?

Answer 3

Pronephros
Mesonephros
Metanephros

Question 4

How permanent are each of the primitive kidney systems?

Answer 4

Pronephros - transient and non-functional
Mesonephros - may function for a short time then regresses
Metanephros - forms the permanent kidney

Question 5

Interactions between which two primitive structures initiates the development of the kidney?

Answer 5

Uretic bud and metanephric mesenchyme

Question 6

What type of interaction is displayed between the uterer bud and the metanephric mesenchyme?

Answer 6

Reciprocal inductive interactions

Question 7

What does the uretic bud induce the mesenchyme to do?

Answer 7

Mesenchymal to epithelia transformation

Question 8

What does the mesenchyme induce the uretic bud to do?

Answer 8

Branching morphogenesis

Question 9

Why do we need to develop kidneys?

Answer 9

Removing toxic nitrogenous waste while conserving water.

Ammonia alone is extremely toxic so needs lots of water to dispose of.

Urea is less toxic so allows conservation of water, but requires specialised structures and physiology to produce it and remove it.

Question 10

What week does the pronephros first develop?

Answer 10

Early 4th week

Question 11

What spinal region does the pronephros initially arise in?

Answer 11

Cervical

Question 12

By what time have the pronephros fully regressed?

Answer 12

The end of the 4th week

Question 13

What week does the mesonephros first develop?

Answer 13

The end of the 4th week

Question 14

What spinal region does the mesonephros initially arise in?

Answer 14

Upper thoracic to upper lumbar (T1-L2/3)

Question 15

How many nephron pairs form on the mesonephros in total?

Answer 15

30

Question 16

In the mesonephros: As caudal nodes develop what happens to rostral nodes?

Answer 16

The degenerate

Question 17

By what week have the majority of the mesonephric nodes dissapeared?

Answer 17

The end of the 8th week

Question 18

Does any mesonephros remain in the adult female? If yes, where?

Answer 18

No

Question 19

Does any mesonephros remain in the adult male? If yes, where?

Answer 19

In males few caudal tubes and mesonephric duct persist as genital duct.

Question 20

When is the mesonephros functional and why does it need to be?

Answer 20

End of the 4th week till regression in the 8th week.

While metanephros is developing

Question 21

What time does the metanephros begin to develop?

Answer 21

The end of the 4th week

Question 22

What ‘forms’ the metanephros?

Answer 22

Epithelial-mesenchymal tissue interaction between ureteric bud and the adjacent metanephric mesenchyme

Question 23

What is the uretic bud?

Answer 23

A diverticulum/outgrowth from mesonephric duct close to cloaca

Question 24

What is the progression of branching morphogenesis of the uretic bud?

Answer 24

Bud dilates and bifurcates, forming the renal pelvis.

Branches coalesce into major calyces.

Further branches form, enlarge and merge to form the minor calyces

Collecting tubules are formed by further branching, they converge on the minor major calyx forming the renal pyramid.

Question 25

How many generations of bifurcation before the branches form major calyces?

Answer 25

4

Question 26

What generation of bifurcation forms the collecting tubules?

Answer 26

5-6th

Question 27

What forms the renal pyramid?

Answer 27

Collecting tubules converging with minor calyx

Question 28

What name describes the tip of each collecting duct?

Answer 28

Ampullae

Question 29

What describes the mesenchyme directly proximal to the ampullae?

Answer 29

Tissue caps

Question 30

What does the collecting duct induce the tissue caps to form?

Answer 30

Small vesicles

Question 31

What do the initial small renal vesicles give rise to?

Answer 31

S-shaped tubules

Question 32

Where does the distal end of the tubule bind?

Answer 32

Fuses with the collecting duct

Question 33

What associates with the proximal end of the tubule?

Answer 33

Capillaries which grow into the pocket, form the glomerulus and Bowman's capsule

Question 34

What does the WNT1 transcription factor induce?

Answer 34

Branching morphogenesis | Causes tissue to respond to the induction of the uretic bud

Question 35

What does WNT1 regulate production of?

Answer 35

GNDF (stimulates branching)

Question 36

What is Wilm's Tumour caused by?

Answer 36

Mutation in the WNT1 gene

Question 37

What are the effects of Wilm's Tumour?

Answer 37

Kidney cancer in children

Question 38

In what weeks does the metanephric kidney ascend?

Answer 38

6th-9th

Question 39

Where does the metanephric kidney move in development?

Answer 39

Ascends to lumbar region (L1/2)

Question 40

What mainly drives kidney ascent?

Answer 40

Differential growth, embryo lengthens but kidneys stay in place

Question 41

As the kidney ascends does its blood supply stay the same? If not, how does it change?

Answer 41

No, changes to higher segmental arteries

Question 42

What divides the cloaca into two?

Answer 42

Urorectal septum

Question 43

What two holes does the cloaca divide into?

Answer 43

Urogenital sinus and the anal canal

Question 44

What does the tip of the urorectal septum become?

Answer 44

The perineal body

Question 45

What does the bladder form from?

Answer 45

The allantois and urogenital sinus

Question 46

What is the allantois?

Answer 46

Outgrowth from the hindgut

Question 47

What forms the bladder?

Answer 47

Superior part of the urogenital sinus continuous with the allantois

Question 48

What connects the bladder with the umbilicus?

Answer 48

Urachus

Question 49

What does the urachus form in the adult?

Answer 49

Medial umbillical ligament

Question 50

What gives rise to the urethras?

Answer 50

The pelvic part of the urogenital sinus

Question 51

Which parts of the male urethra develop from the pelvic urogenital sinus?

Answer 51

Prostatic and membranous

Question 52

What part of the urogenital sinus forms the penile urethra?

Answer 52

Phallic

Question 53

What does the pelvis urogenital sinus form in females?

Answer 53

Membranous urethra

Question 54

Why do the ureters enter the bladder separately?

Answer 54

Mesonephric ducts are absorbed by the bladder

Question 55

What forms the mesodermal trigone?

Answer 55

Mesonephric ducts merging with the bladder (uretic orifices)

Question 56

Initially what germ layer forms the trigone?

Answer 56

Mesoderm

Question 57

Over time how does the trigone change?

Answer 57

Mesodermal lining changed with endodermal epithelium

Question 58

How is the trigone distinct?

Answer 58

Mesoderm while rest of the bladder is endoderm

Question 59

How is the trigone different in males?

Answer 59

More prominent as the mesonephric ducts regress less

Question 60

What 'spinal' region does the pronephros form in?

Answer 60

Cervical

Question 61

The trigone is formed by...

Answer 61

Incorporation of the distal ends of the mesonephric ducts

Question 62

What does the allantois form?

Answer 62

The apex of the bladder and the urachus

Question 63

What does uretic bud form?

Answer 63

Renal pelvis, calyces, collecting ducts

Question 64

What forms the ureter?

Answer 64

Ureteric bud