Overview of embryology and congenital malformations

Question 1

What is the period of organogenesis?

Answer 1

production and development of the organs of animals and plants

Question 2

What are the derivatives of the ectoderm?

Answer 2

• gives rise to organs and structures that maintain contact with the outside world
• forms neuroectoderm that leads to formation of neural tubes

Question 3

What are the 3 sub-types of the mesoderm?

Answer 3

paraxial mesoderm, intermediate mesoderm and lateral plate mesoderm

Question 4

What does the paraxial mesoderm give rise to?

Answer 4

• forms segmented blocks called somiteres
• each day new somites appear - at a rate of 3 per day
• at the end of 5th week there are 42-44 pairs
• allows the age of the embryo to be accurately calculated

Question 5

What does the lateral plate mesoderm give rise to?

Answer 5

parietal and visceral layers

Question 6

What are the derivative of the endoderm?

Answer 6

• gastrointestinal tract
• forms epithelial layer of respiratory tract, urinary bladder and urethra
• forms paranchyma of thyroid, parathyroids, liver and pancrea

Question 7

what is malformation syndrome?

Answer 7

occurs as a pattern of well characterised multiple primary malformations
e.g. Downs syndrome/FASD

Question 8

What is malformation sequence?

Answer 8

appearance of patterns of a cascade subsequent related multiple structural defects

Question 9

What is malformation field defects?

Answer 9

related malformations in a particular region of the body

Question 10

What is malformation association?

Answer 10

non-random appearance of 2 or more groups of anomalies that occur together