Embryology

Question 1

What is the ampulla?

Answer 1

site of fertilisation

Question 2

What is the zona pellucida?

Answer 2

Tough protective protein layer surrounding oocyte

- Stops embryo from sticking in the fallopian tube

Question 3

how does the sperm get through the zona pellucida?

Answer 3

acrosomal enzymes are released from the sperm head which digest the zona pellucida

Question 4

What is a trophoblast?

Answer 4

Cells that line the zona pellucida

- Go on to form the placenta

Question 5

what is the oropharyngeal membrane?

Answer 5

Site of future mouth

Question 6

What is gastrulation?

Answer 6

formation of tissue (Germ) layers

Question 7

What does the term morphogenesis mean?

Answer 7

Formation of the body plan (embryonic folding)

Question 8

Whats is meant by the term induction?

Answer 8

The ability one cell type to cause another to differentiate

Question 9

What does epigenetic mean?

Answer 9

Preferential expression of either the maternal or the paternal copy of a gene

Question 10

On which day is implantation complete

Answer 10

Day 9

Question 11

After gastrulation what does the ectoderm become?

Answer 11

• Epidermis of the skin

Question 12

After gastrulation what does the endoderm become?

Answer 12

• Lining of the gut tube

- Lining of the respiratory tract

Question 13

After gastrulation what does the mesoderm become?

Answer 13

Mesoderm becomes divided into 3 regions either side of the notochord

Question 14

3rd month features

Answer 14

• Face more human looking
• Lengthening of limbs
• Ossification of long bones and skull
• Can determine Gender

Question 15

4th and 5th month

Answer 15

Rapid increase in length

Question 16

6th month –> Birth

Answer 16

Rapid increase in weight gain

Question 17

Causes of Defects

Answer 17

• Infectious agent
• Radiation
• Chemical agents and prescription drugs
• Nutritional Deficiencies
• Maternal Disease

Question 18

What happens during lateral folding

Answer 18

• Converts the open coelom into a closed cavity

- Creates thoracic and abdominal cavities and closing fore and hindgut

Question 19

What happens during Cranial Folding

Answer 19

Forms the foregut

Defines the thoracic cavity

Question 20

What happens during caudal folding

Answer 20

Cloacal membrane and connecting stalk are displaced ventrally alongside the neck of the yolk sac

Froms:
Hindgut
Anus
And Umbilical Cord

Question 21

When does the heart begin to develop

Answer 21

Week 4

Question 22

Name the two cardiac Septa

Answer 22

1. Septum Primum (flexible)

2. Septum Secundum ( more rigid)

Question 23

What happens during probe patent foramen ovale

Answer 23

• Septum prison and septum secundum fail to fuse
• mixing of blood prevented due to pressure difference

can go entire life without knowing you have this

Question 24

Define Transposition of the great vessels

Answer 24

Aorta exits right ventricle
Pulmonary trunk exits left ventricle
Deoxygenated blood pumped around the body

THIS ARRISES DUE TO THE SPIRALLING SEPTUM - IF IT FAILS TO SPIRAL THESE PROBLEMS CAN ARISE

Question 25

What are the four components of TETRALOGY OF FALLOUT

Answer 25

1. Pulmonary Stenosis
2. Hypertrophy of the left ventricle
3. VSD
4. Over - riding aorta