Urinary Embryology

Question 1

What are the components of the urinary system?

Answer 1

Kidneys
Ureter
Bladder
Urethra

Question 2

What are the components of the kidneys?

Answer 2

Nephron
Collecting duct
Calyces and pelvis

Question 3

What is the role of the urethra?

Answer 3

Takes the urine from the bladder to the exterior of the body

Question 4

Which part of the mesoderm forms the urogenital system?

Answer 4

Intermediate plate mesoderm

Question 5

What is the allantois?

Answer 5

Pouch of the endoderm at the hindgut which extents into the body stalk.

Question 6

What happens in the allantois?

Answer 6

Waste products are collected- they then go into the umbilical cord and through the placenta into the maternal system

Question 7

Cloaca?

Answer 7

Single posterior opening for a bird’s digestive, urinary and reproductive tracts

->for poo and eggs x

Question 8

What does the allantois grow to become?

Answer 8

Body stalk which then goes on to form the umbilicus

Question 9

What happens to the cloaca in humans?

Answer 9

Is divided by mesoderm into an anterior and posterior part

Question 10

What does the cloaca divide into posteriorly?

Answer 10

Rectum

Question 11

What does the cloaca divide into anteriorly?

Answer 11

Urogenital sinus

Question 12

What does the urogenital sinus go onto form?

Answer 12

Urinary bladder

Question 13

What does the allantois go onto form?

Answer 13

Urachus*

*a remnant of a channel between the bladder and the umbilicus where urine initially drains in the fetus during the 1st trimester of pregnancy.

Question 14

What happens to the allantois after birth?

Answer 14

Gets obliterated and forms anterior part of bladder

Question 15

What happens to the intermediate mesoderm in the neck region during the fourth week of development?

Answer 15

Becomes the pronephros

Question 16

What does the pronephros become?

Answer 16

Pronephric duct
Rudimentary pronephric tubules

Question 17

What does the pronephric duct drain into?

Answer 17

Cloaca

Question 18

During which week of development does the pronephros mainly degenerate, except from the pronephric duct?

Answer 18

5th week

Question 19

What does the pronephric duct become?

Answer 19

Mesonephric duct

Question 20

What takes over from the pronephros?

Answer 20

Mesonephros

Question 21

What is the role of the mesonephros?

Answer 21

Functions as the kidneys for four weeks

Question 22

After four weeks, the mesonephros starts the degenerate, what takes over?

Answer 22

Metanephros

Question 23

What does the metanephros become?

Answer 23

Definitive kidney

Question 24

What does the metanephros consist of?

Answer 24

Ureteric bud that comes off the mesonephric duct
Metanephric mesoderm

Question 25

What do the mesonephric tubules become?

Answer 25

Testes

->in females, the mesonephros becomes the ovary but the ducts and tubules degenerate

Question 26

What does the mesonephric duct become?

Answer 26

Vas deferens

Question 27

Where is the definitive kidney formed from?

Answer 27

Metanephric mesoderm, part of the intermediate mesoderm

Question 28

Where is the ureter formed from?

Answer 28

Ureteric duct

Question 29

The uretic bud undergoes repeated branching at it’s distal end.
What do the first 4 generations of branches become?

Answer 29

Major calyces

->next four generations become the minor calyces, remaining generations form the collecting tubules

Question 30

What does the nephron develop from?

Answer 30

Metanephric mesoderm

Question 31

List the structures that develop from the ureteric bud.

Answer 31

Ureter, collecting duct, calyces

Question 32

At what vertebral level do the kidneys end up at?

Answer 32

T12-L3

Question 33

What is meant by a horse-shoe shaped kidney?

Answer 33

The lower poles of the two kidneys fuse together causing a horseshoe shape