Embryology

Question 1

Trisomy 21 - Down’s syndrome

Answer 1

Growth retardation
Intellectual retardation
Craniofacial abnormalities
Congenital heart defects

Question 2

TORCH - Infections that cross the placenta

Answer 2

Toxoplasmosis 
Other (HepB, Synthesis)
Rubella
Cytomegalovirus
Herpes

Question 3

Toxoplasmosis

Answer 3

Parasite
Found in cat faeces and undercooked/raw meat
usually asymptomatic
Congenital malformations include micropthalmia (inflammation of retina and eye), hearing loss, hydrocephaly (fluid in the brain), microcephaly (when head and brain doesn’t form properly)

Question 4

Other (HepB, Syphilis)

Congenital malformations?

Answer 4

Congenital malformations include cloudy cornea, intellectual disability, microcephaly and heart defects

Question 5

Cytomegalovirus

Congenital malformations?

Answer 5

Congenital malformations include micropthalmia, enlarged spleen or liver, mineral deposits on the brain, microcephaly, psychomotor retardation

Question 6

Herpes

Congenital malformations?

Answer 6

Congenital malformations include segmental skinloss/scarring, limb hypoplasia, microcephaly and visual defects

Question 7

Zika Virus

Answer 7

Mosquitos
Fever, rash, joint pain, red eyes
Congenital malformations include microcephaly

Question 8

Foetal alcohol syndrome

Answer 8

Clear relationship between alcohol consumption and congenital abnormalities
Congenital malformations include prenatal and postnatal growth retardation, intellectual disability and impaired motor ability and co-ordination

Question 9

Folic acid deficiency

Answer 9

Malformations in CN formation
OTC supplements reduce risk of malformation by 60%
Causes spina bifida and anencephaly

Question 10

Placenta previa

Answer 10

Ectopic pregnancy

Implantation in the cervix

Question 11

Tubal implantation

Answer 11

Ectopic pregnancy

Implantation in the uterine tube (80% in the ampulla)

Question 12

Abdominal implantation

Answer 12

Fertilised egg enters the abdomen

Question 13

Lithopaedion

Answer 13

When abdominal pregnancy isn’t diagnosed and foetus dies

The foetus is too large to be reabsorbed so it calcifies

Question 14

Hydatidiform mole

Answer 14

Development of the trophoblast without any embryonic tissue due to fertilisation of an ‘empty’ egg lacking a nucleus

Question 15

Sinus invertus

Answer 15

Right and left symmetry of the body is reversed
Asymptomatic
Problems arise when some systems are switched but others aren’t (Kartagener syndrome)

Question 16

Sirenomelia

Answer 16

Mermaid syndrome’
Insufficient mesoderm is formed in the caudal region of the embryo - abnormalities of urogenital system and lower limbs
Primitive streak closes off too early so we don’t have sufficient migration of epiblast cells

Question 17

Sacrococcygeal Teratoma

Answer 17

Excessive migration of epiblast through primitive streak so too much mesoderm is made
Remnants of primitive streak may persist and give rise to tumour

Question 18

Anencephaly

Answer 18

Failure of the anterior neuropore to fuse
The forebrain doesn’t form
A brainstem is present and normally exposed

Question 19

Rachischisis

Answer 19

Failure of the posterior neuropore to fuse
Spinal cord does not form properly leading to paralysis
Spina bifida - open neural tube prevents formation of vertebra
Flat plate of neural tissue is exposed at birth - high risk of infection

Question 20

Neurofibromatosis

Answer 20

A genetic condition caused by a mutation in neurofibromin 1 (NF1) gene
NF1 is a tumour suppressor gene that is ‘switched off’ in neurofibromatosis leading to increased cell division
Benign tumours of the nervous system, skin and cranial bones

Question 21

Ectopia cordis

Answer 21

Lateral folds fail to fuse in the thoracic region leaving the heart outside the body

Question 22

Gastroschisis

Answer 22

Lateral folds fail to fuse in abdominal region leaving the intestines outside the body wall