3: Embryology

Question 1

What germ layer do the kidneys originate from?

Answer 1

Mesoderm

Question 2

Which particular part of the mesoderm do the kidneys develop from?

Answer 2

Intermediate mesoderm

Question 3

What structure do the kidneys originate from?

Answer 3

Pronephros

Question 4

The pronephros develops into which structure?

Answer 4

Mesonephros

Question 5

How does the pronephros descend into its correct position for development?

Answer 5

Mesonephric duct

Question 6

What does the mesonephros develop into, forming the permanent kidney?

Answer 6

Metanephros

Question 7

Which embryological structures do the metanephros develop from?

Answer 7

Ureteric bud

Metanephric blastema

Question 8

What duct does the ureteric bud come from?

Answer 8

Mesonephric duct

Question 9

What is the other origin of the kidneys apart from the ureteric bud?

Which germ layer does it come from?

Answer 9

Metanephric blastema

Intermediate mesoderm in the sacrum

Question 10

The ___ ___ pushes into the ___ ___.

(ureteric bud, metanephric blastema)

Answer 10

ureteric bud pushes into the metanephric blastema

Question 11

What happens when the ureteric bud fails to push into the metanephric blastema?

Answer 11

Kidney agenesis

Lack of a kidney

Question 12

What structures of the kidney does the ureteric bud develop into?

Answer 12

Collecting system

so the collecting ducts all the way to the ureters

Question 13

What embryological origin of the kidney forms the nephrons themselves?

Answer 13

Metanephric blastema

Question 14

What embryological structures form the

a) collecting system
b) nephrons

of the kidney?

Answer 14

a) Ureteric bud

b) Metanephric blastema

Question 15

Which body cavity do the kidneys originate in?

What do they need to do after that?

Answer 15

Pelvic cavity

Ascend to the retroperitoneal space of the abdomen

Question 16

After they’ve ascended, are the kidneys intraperitoneal or retroperitoneal?

Answer 16

retroperitoneal

Question 17

As the kidneys ascend from the pelvis to the abdomen, which blood vessel do they draw a supply from?

Answer 17

Abdominal aorta

Question 18

As the kidneys rise, the vessels they draw blood from degenerate. What happens when this doesn’t occur?

Answer 18

Accessory renal arteries

Question 19

What can happen if one or both kidneys fail to ascend?

Answer 19

Pelvic kidney

Remains in the pelvis

Question 20

What is a horseshoe kidney?

Answer 20

Metanephrons (pre-kidneys) FUSE at inferior poles, make a weird horseshoe shape and are more inferior than normal

Question 21

What is the cloaca?

Answer 21

Early hindgut with ONE opening for the GI, renal and reproductive tracts

Question 22

What germ layer does the cloaca originate from?

Answer 22

Endoderm

Question 23

In which space do the bladder, urethra and rectum develop?

Answer 23

Primitive urogenital sinus

Question 24

What is the difference between the primitive and definitive urogenital sinuses?

Answer 24

Primitive urogenital sinus forms earlier and has openings for GI, renal and repro tracts

Definitive urogenitial sinus separates from anorectal canal and has urethra and bladder only

Question 25

What does the **definitive urogenital sinus** develop into?

Answer 25

**Urethra** and **bladder**

Question 26

How do the **mesonephric ducts** factor in to the development of the bladder?

Answer 26

**Form the posterior wall, which becomes the trigone**

Question 27

What structure, found **superior** to the bladder, exits in the umbilical cord to drain the bladder of the fetus?

Answer 27

**Allantois**

Question 28

What does the allantois develop into in adults?

Answer 28

**Urachus** closed off space

Question 29

Problems with the ___ can cause bladder defects in newborns.

Answer 29

**urachus**