Embryology

Question 1

What is a morula?

Answer 1

After zygote

Solid ball of cells

Question 2

Leber’s hereditary optic neuropathy is an example of what?

Answer 2

Mitochondrial disease

Question 3

What makes up a blastocyst?

Answer 3

Trophoblast (outside)
Inner cell mass
Blastocyst cavity

Question 4

The trophoblast forms what for implantation?

Answer 4

Chorion

Question 5

What does the chorion do?

Answer 5

Implantation (chorionic villi)
Forms placenta
Secretes human Chorionic gonadatrophin

Question 6

What happens to the inner cell mass of the trophoblast?

Answer 6

Bilaminar disc

• Epiblast
• Hypoblast

Question 7

What are the functions of the placenta?

Answer 7

Foetal nutrition
Transport of waste and gases
Immune system

Question 8

What forms the maternal part of the placenta?

Answer 8

Decidua basalis of the endometrium

Question 9

What forms in the centre of the epiblast?

Answer 9

Primitive streak (invagination of cells)

Question 10

The epiblast displaces what and forms what?

Answer 10

Displaces the hypoblast
Forms the germ layers
- Ectoderm
- Mesoderm
- Endoderm

Question 11

What is the first thing the ectoderm forms?

Answer 11

Notochord

Question 12

What does the notochord induce?

Answer 12

Sinking of the neural plate to form a neural tube

Question 13

What does the neural tube induce?

Answer 13

Thickening of the mesoderm and separation

Question 14

What does the mesoderm separate into?

Answer 14

Paraxial Mesoderm
Intermediate plate mesoderm
Lateral plate mesoderm

Question 15

What does the lateral plate mesoderm split into?

Answer 15

Somatic mesoderm
Intraembryonic coelom
Splanchic mesoderm

Question 16

What does the paraxial mesoderm form?

Answer 16

Somites

Question 17

What does the intermediate plate mesoderm form?

Answer 17

Urogenital system

Question 18

Neurolation forms what?

Answer 18

43 pairs of somites in paraxial mesoderm

Question 19

The endoderm forms what?

Answer 19

Gut tube

Respiratory

Question 20

The somites divide into what?

Answer 20

Dermatome (dermis of skin)
Myotome (muscle)
Sclerotome (bone)

Question 21

What does ToRCH stand for?

Answer 21

Infections teratogens
Toxoplasmosis
Rubella
Cytomegalovirus
Herpes

Question 22

Where is the risk of teratogenesis greatest?

Answer 22

weeks 3-8

Question 23

How is a prenatal diagnosis of congenital disorders made?

Answer 23

Blood - AFP
Ultrasound (12 weeks)
CVS/amniocentesis

Question 24

How is a postnatal diagnosis of congenital disorders made?

Answer 24

Hip stability
Testicular descent
Fingers and toes
Hearing