Embryology

Question 1

What does the paraxial mesoderm form?

Answer 1

Somite

Question 2

What does the intermediate plate mesoderm form?

Answer 2

Urogenital system

Question 3

What does the Lateral plate mesoderm form?

Answer 3

Body cavity and coverings (peritoneum)

Question 4

How is the kidney peritonised?

Answer 4

Retroperitoneal

Question 5

What is an Allantois?

Answer 5

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

Question 6

What does the body stalk form?

Answer 6

Umbilical cord

Question 7

What does the Cloaca divide into?

Answer 7

Rectum and Urogenital sinus

Question 8

What does the Urogenital sinus divide into?

Answer 8

Bladder and Urethra (at caudal end)

Question 9

What is the Median umbilical ligament?

Answer 9

Remnant of the Allantois

Question 10

What supplies the bladder?

Answer 10

The Superior Vesical Artery (Umbilical Artery)

Question 11

What drains into the urogenital sinus?

Answer 11

Mesonephric duct

Question 12

What is the process called during Kidney formation?

Answer 12

Nephrogenesis

Question 13

What happens during week 4?

Answer 13

The intermediate mesoderm in the neck region of embryo becomes the pronephros

Question 14

What is the pronephros?

Answer 14

Pronephric duct + rudimentary pronephric tubules

Question 15

What drains into the Cloaca?

Answer 15

Pronephric duct

Question 16

What happens to the pronephros?

Answer 16

Degenerates by Week 5 except the pronephric duct

Question 17

What happens to the Intermediate mesoderm in the trunk region?

Answer 17

Becomes the Mesonephros

Question 18

When does the Mesonephros develop

Answer 18

Late Week 4

Question 19

What becomes the Mesonephric duct?

Answer 19

The pronephric duct

Question 20

What drains into the Mesonephric duct?

Answer 20

The Mesonephric tubules

Question 21

What does the Mesonephros do?

Answer 21

Functions as a Kidney for 4 weeks

Question 22

When does the Metanephros start to function?

Answer 22

Week 9

Question 23

What does a Metanephros consist of?

Answer 23

• A ureteric bud that develops off the mesonephric duct

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

Question 24

What does the Mesonephric tubules become?

Answer 24

The Rete Testis

Question 25

What does the Mesonephric duct become?

Answer 25

The Vas Deferens

Question 26

What does the Mesonephros become in females?

Answer 26

Ovaries but the tubules and the mesonephric duct degenerate

Question 27

What does the Mesonephros become?

Answer 27

Developing gonad

Question 28

What do undifferentiated cells from the yolk sac do?

Answer 28

They migrate to form the spermatogonia or oogonia

Question 29

When does the Metanephros start to develop?

Answer 29

Week 5

Question 30

What does the Metanephros develop into?

Answer 30

Ureteric bud

Question 31

Describe the process of developing the kidney?

Answer 31

- The ureteric bud undergoes repeated branching at its distal end - The stalk becomes the ureter - The expanded cranial end becomes the renal pelvis - The first 4 generations of branches become confluent to become the major calyces - The next 4 generations form the minor calyces - The remaining generations become the collecting tubules

Question 32

Describe the process of the development of the nephron?

Answer 32

- Week 8 the mesoderm to epithelium transitions - The epithelium forms the Metanephric vesicle which then changes into the Metanephric tubule - The Metanephric tubule binds the the collecting duct - The Glomerulus invaginate the nephron (metanephric tubule) - The uniferous tubule lengthens - Formation of the nephrons continue until week 32 - At birth each kidney contains approx. 1x10^6 nephrons

Question 33

What is a nephron?

Answer 33

Renal corpuscle + Proximal collecting tubule + Loop of Henle + Descending collecting tubule

Question 34

What is the Urineiferous tubule?

Answer 34

Nephron + Collecting duct

Question 35

What develops from the Ureteric bud?

Answer 35

Collecting duct, Calyces, pelvis, ureter

Question 36

What develops from metanephric mesoderm?

Answer 36

Nephron

Question 37

Describe how the Kidney's ascend?

Answer 37

- Kidneys initially lie on either side of the bladder and in the developing pelvis - Ascend due to differential growth of lower body inferably away from the kidneys - Ascent stops when Kidneys come into contact of the Adrenal gland - Lies in upper abdomen (T12-L3) - The hilum rotates from ventral to medial (90 degrees) - Happens around week 6 - Segmental breakdown and reform of vascular supply during ascent

Question 38

List developing anomalies of the Kidney

Answer 38

- Double ureter - Double Pelvis (single ureter) - 2 Kidney's the same side - Congenital polycystic Kidney - Aberrant renal arteries - Lobulated Kidney - Transposition of Kidney - Horseshoe Kidney - Pancake Kidney