Embryology

Question 1

What are the components of the adult urinary system?

Answer 1

• Kidneys
• Ureter
• Bladder
• Urethra
• Blood supply

Question 2

What are the components of the kidney?

Answer 2

• Nephron
• Collecting duct
• Calyces and pelvis

Question 3

What does the paraxial mesoderm form?

Answer 3

Somites

Question 4

What does the intermediate plate mesoderm form?

Answer 4

Urogenital system (kidneys and repro)

Question 5

What does the lateral plate mesoderm form?

Answer 5

Body cavity and coverings

Question 6

What position does the intermediate mesoderm take?

Answer 6

Retroperitoneal

Question 7

What is the allantois?

Answer 7

An out pouching of endoderm at the hindgut that extends into the body stalk

Question 8

What does the body stalk later form?

Answer 8

Umbilical cord

Question 9

Cloaca

Answer 9

The cloaca is the single posterior opening for a bird’s digestive, urinary and reproductive tracts and is used to expel faeces and lay eggs.

Question 10

What does the cloaca divide to form?

Answer 10

• Posteriorly rectum (GIT)

- Anteriorly the urogenital sinus

Question 11

What doe the mesonephric duct drain into?

Answer 11

Urogenital sinus

Question 12

What does the urogenital sinus later form?

Answer 12

Urinary bladder and its caudal end forms the urethra

Question 13

How many sets of kidneys develop during nephrogenesis?

Answer 13

3 sets of kidneys develop sequentially

Question 14

What does the intermediate mesoderm in the neck region become early in the 4th week?

Answer 14

Pronephros

Question 15

What is the pronephros made up of?

Answer 15

Pronephric duct and rudimentary pronephric tubules

Question 16

What does the pronephric duct drain into?

Answer 16

Cloaca

Question 17

What happens to the pronephros?

Answer 17

It mainly degenerates by week 5

Question 18

What does the intermediate mesoderm in the trunk region become late in the 4th week?

Answer 18

Mesonephros

Question 19

What does the pronephric duct become?

Answer 19

Mesonephric duct

Question 20

What drains into the mesonephric duct?

Answer 20

Mesonephric tubules

Question 21

When does the metanephros start to develop?

Answer 21

About week 5

Question 22

When does the metanephros start to function?

Answer 22

About week 9

Question 23

What does the metanephros consist of?

Answer 23

• A ureteric bud that develops off the mesonephric duct

- Metanephric mesoderm (the most caudal part of the intermediate mesoderm)

Question 24

What happens to the mesonephros?

Answer 24

Much of the mesonephros will be incorporated into the developing gonad

Question 25

What do undifferentiated cells from the yolk sac migrate to form?

Answer 25

Spermatogonia/oogonia

Question 26

What becomes the rete testis?

Answer 26

Mesonephric tubules

Question 27

What becomes the vas deferens?

Answer 27

Mesonephric duct

Question 28

What happens to the mesnephros in females?

Answer 28

In females the mesnephros becomes the ovary

Question 29

What happens to the mesonephric duct in females?

Answer 29

The tubules and mesonephric duct degenerate

Question 30

What happens to the ureteric bud at its distal end?

Answer 30

Undergoes repeated branching

Question 31

What does the stalk of the ureteric bud become?

Answer 31

Ureter

Question 32

What does the expanded cranial end of the ureteric bud become?

Answer 32

Renal pelvis

Question 33

What do the first 4 generations of branches of the ureteric bud become?

Answer 33

Major calyces

Question 34

What forms the minor calyces?

Answer 34

Generations 5-8 of the branches of the ureteric bud

Question 35

What forms the collecting tubules?

Answer 35

The remaining branches (ones that haven't formed the calyces) of the ureteric bud

Question 36

What reciprocally induce each other?

Answer 36

Ureteric bud and the metanephric mesoderm

Question 37

What are the components of a nephron?

Answer 37

- Renal corpuscle - Proximal collecting tubule - Loop of Henle - Distal collecting tubule

Question 38

What are the components of a uriniferous tubule?

Answer 38

- Nephron | - Collecting duct

Question 39

What does the nephron develop from?

Answer 39

Metanephric mesoderm

Question 40

What do the collecting duct, calyces, pelvis and ureter develop from?

Answer 40

Ureteric bud

Question 41

Where do the kidneys initially lie?

Answer 41

Kidneys initially lie on either side of the bladder and in the developing pelvis

Question 42

Why do the kidneys 'ascend' into the abdomen?

Answer 42

Mainly due to differential growth of lower body inferiorly away from kidneys

Question 43

What is the final vertebral level of the kidneys?

Answer 43

T12-L3

Question 44

How does the hilum of the kidney rotate?

Answer 44

From ventral to medial through 90 degrees

Question 45

When does ascent of the kidneys stop?

Answer 45

When they come into contact with the adrenal glands

Question 46

What happens alongside the ascent of the kidneys?

Answer 46

Segmental breakdown and reform of vascular supply

Question 47

What anomalies may occur during development?

Answer 47

- Double ureters - Abnormal sites of ureter opening - Congenital polycystic kidneys - Aberrant renal arteries - Lobulated kidney - Transposition of kidney - Horseshow kidney - Pancake kidney

Question 48

How long does the mesonephros function as the kidneys?

Answer 48

Approx 4 weeks