principles of congenital malformations

Question 1

morphogenesis

Answer 1

a form-shaping process in an embryo, controlled by fundamental cell behaviours that result in differential tissue growth.

Question 2

dysmorphogenesis and birth defects result from

Answer 2

Interference with differential tissue growth in an embryo, that could be occasioned by genetic mutation, teratogen exposure or a combination of these two processes

Question 3

cellular behaviours involved in morphogenesis include

Answer 3

changes in cell shape, size, position, number, and adhesivity.

Question 4

what is the norm…

Answer 4

what is most people have, so 2 legs is the norm because most people have 2 legs

Question 5

what is normogenesis

Answer 5

individuals that develop close to the range of normal - developed normally

Question 6

structural birth defects involve both

Answer 6

malformations and deformations resulting from abnormal development

Question 7

Malformations consist of

Answer 7

primary morphologic defects in an organ or body part and result from disturbance of developmental events or processes directly involved in the formation of a particular structure

Question 8

example of a malformation

Answer 8

NTD - due to non closure of the neural folds or (ancephaly)

Question 9

malformations can be caused by

Answer 9

environmental (teratogens) and/or genetic factors acting independently or together.

Question 10

deformations consist of

Answer 10

secondary morphologic defects that are imposed upon an organ or body part due to mechanical forces over a prolonged period – an indirect effect.

Question 11

example of a deformation

Answer 11

Clubfeet due to compression in the amniotic cavity as a result of insufficient amniotic fluid (Oligohydramnios).

Question 12

deformations are common with

Answer 12

skeletal system development

Question 13

most deformations have

Answer 13

very good and excellent prognosis and very low recurrence risk in contrast with many malformations

Question 14

Disruptions result in

Answer 14

morphological alterations of already formed structures due to destructive processes.

Question 15

Defects produced by amniotic bands

Answer 15

cleft lip, toe and finger amputations.

Question 16

examples of malformation syndromes

Answer 16

downs syndrome and foetal alcohol syndrome

Question 17

what is a syndrome

Answer 17

dysmorphogenesis in one or more tissues due to specific single underlying cause

Question 18

Down syndrome (Trisomy 21)
- symptoms

Answer 18

Flat facial feature with a small nose
Reduced muscle tone (Hypotonia)
Upward/Downward slant to the eye
Enlarge tongue that tends to stick out
Single deep crease across the centre of the palm
Hyperflexibility (extension) of the joints.
ETC

Question 19

Foetal alcohol syndrome (or Foetal alcohol spectrum disorder - SYMPTOMS

Answer 19

Short palpebral fissure lengths
Smooth philtrum
Thin upper lip
Brain damage
ETC

Question 20

what is teratology?

Answer 20

a term used to describe the study of birth defect or congenital malformation or congenital anomaly.

Question 21

what is a teratogen?

Answer 21

any factor or agent that causes birth defect or congenital malformation or congenital anomaly

Question 22

what factors are said to determine the capacity of an agent to produce a birth defect

Answer 22

Genotype of the conceptus and the maternal genome.

Developmental stage at the time of exposure to teratogens.

Dose and duration of exposure to a teratogen.

Question 23

The mechanism of action of a teratogen is

Answer 23

the specific ways in which it acts on developing cells and tissues to initiate abnormal embryogenesis.

Question 24

Pathogenesis is

Answer 24

the abnormal developmental processes that result to Dysmorphogenesis.

Question 25

The mechanisms of teratogens may involve

Answer 25

inhibition of a specific biochemical or molecular process.

Question 26

Pathogenesis may involve

Answer 26

involve cell death, decreased cell proliferation, or other cellular phenomena.

Question 27

Manifestations of abnormal development are

Answer 27

death, malformation, growth retardation, and functional disorders.