Maldevelopment

Question 1

What is spina bifida

Answer 1

Fusion of the spinal cord should be complete by week 4 but in spina bifida, the posterior neuropore doesn’t close properly (failure of neurulation)

Question 2

What is cleft palate

Answer 2

A defect posterior to the incisive foramen. Failure of tissue migration to complete fill the midline grooves.

Question 3

What is Tetralogy of Fallot

Answer 3

Classically 4 defects= Pulmonary stenosis, thickening of right ventricle, ventricular septal defect and malpositioned aorta

Question 4

What is Atrial septal defect

Answer 4

Caused by patent foramen ovale. Blood flows between both atria.

Question 5

What is Achondroplasia

Answer 5

Normal sized torso and short limbs

Question 6

What is Polydactyly

Answer 6

One or more extra finger or toes

Question 7

What is a teratogen

Answer 7

Any agent that can disturb the development of an embryo or fetus

Question 8

Give examples of infectious teratogens

Answer 8

rubella virus, herpes simplex virus, HIV

Question 9

Give examples of physical agents that are teratogens

Answer 9

X-rays + other ionising radiation - Microcephaly, spina bifida, cleft palate, limb defects

Question 10

Give examples of chemical agents that are teratogens

Answer 10

Thalidomide - Limb defects, heart malformations
Lithium - Heart malformations
Amphetamines - Cleft lip and palate, heart defects
Cocaine - Growth restriction, microcephaly, behavioral abnormalities
Alcohol - Fetal alcohol syndrome, maxillary hypoplasia, heart defects

Question 11

What are the proportions of causes of maldevelopment

Answer 11

Genetic – 30%
Environmental – 15%
Multifactorial – 55%

Question 12

What is anencephaly and how does it affect different genders

Answer 12

Defect in skull and brain development
Anterior neuropore closure incomplete (top of neuropore)
Female babies affected more commonly than male

Question 13

What is the effect of thalidomide on child development

Answer 13

Affects rapidly developing blood vessels, notably those of upper limbs
In addition, deformed eyes and hearts, deformed alimentary and urinary tracts, blindness and deafness.

Question 14

What is thalidomide still used in treatment of

Answer 14

leprosy and cancer treatments at present.

Question 15

What is the difference between Myelomeningocele, Meningocele and Spina bifida occulta

Answer 15

Myelomeningocele – neural tissue in bulge.
Meningocele – no neural tissue in bulge.
Spina bifida occulta – hair growth over area affected, no growth