Embryology

Question 1

What are the four adjectives relating to the directions of an embryo?

Answer 1

Ventral
Dorsal
Caudal
Cranial

Question 2

What is the embryonic period?

Answer 2

Fertilisation to end of week 8

Question 3

What is the foetal period?

Answer 3

Week 9 to birth

Question 4

What is ectopic implantation?

Answer 4

Implantation of the foetus outside of the uterus

Question 5

What are the two versions of the embryo in week 1?

Answer 5

Morula
Blastocyst

Question 6

What are the two layers of the bilaminar embryonic disc?

Answer 6

Epiblast
Hypoblast

Question 7

What forms from the epiblast?

Answer 7

Amnion

Question 8

What forms from the hypoblast?

Answer 8

Umbilical vesicle - yolk sac

Question 9

What usually happens when there are developmental anomalies within the first 2 weeks of development?

Answer 9

Spontaneous abortion

Question 10

What is gastrulation?

Answer 10

Formation of 3 definitive germ layers

Question 11

What is teratology?

Answer 11

Study pf developmental anomalies, birth defects and their causes

Question 12

What are the four problems that may occur during development?

Answer 12

Malformation
Deformation
Dysplasia
Disruption

Question 13

What is a malformation?

Answer 13

Morphologic defect of an organ or larger body region

Question 14

What may a malformation result in?

Answer 14

Anomalies in cell differentiation, migration, proliferation and death

Question 15

What are some examples of malformations?

Answer 15

Congenital heart defect
Hemivertebrae

Question 16

What is a deformation?

Answer 16

Abnormal shape or position of a body resulting from mechanical forces

Question 17

What system is usually involved in a deformation?

Answer 17

Musculoskeletal system

Question 18

What is a disruption?

Answer 18

Morphological defect of an organ or a larger body region resulting from external breakdown or interference with the normal developmental process

Question 19

What is a dysplasia?

Answer 19

Abnormal organisation of cells in tissues and its morphological results

Question 20

What are the four possible patterns of defects?

Answer 20

Sequence
Syndrome
Field defect
Association

Question 21

What is a sequence?

Answer 21

Cascade of defects arising from a single known or presumed structural defect or mechanical factor

Question 22

Name two sequences.

Answer 22

Pierre robin sequence
Potter sequence

Question 23

What is a syndrome?

Answer 23

Multiple defects that occur together in a predictable way

Question 24

What is a field defect?

Answer 24

Multiple anomalies in the same developmental region

Question 25

What is an association?

Answer 25

Non-random, pathogenically unrelated, multiple defects

Question 26

When is an association diagnosed?

Answer 26

If it doesn't fit under the umbrellas of field defect, syndrome or sequence

Question 27

What are the two layers that the trophoblast proliferates into?

Answer 27

Cytotrophoblast - faces inward toward uterine cavity Synctiotrophoblast - Digests the uterine matrix

Question 28

What are the three parts of the trophoblast?

Answer 28

Cytotrophoblast - White circles Synctiotrophoblast - outermost, green Trophoblastic lacuna - red part

Question 29

What are the name of the two embryonic cavities?

Answer 29

Amniotic cavity Yolk sac cavity

Question 30

What is the name of the cavity in the centre of the embryo?

Answer 30

Chorionic cavity

Question 31

What are congenital defects?

Answer 31

Depending on mutations, teratogen, exposure, timing, a number of anomalies

Question 32

What are the 4 congenital defects?

Answer 32

Reduction defects Duplication defects Dysplasia Defomations

Question 33

What term is used for the absence of hands?

Answer 33

Acheiria

Question 34

What term is used for the absence of feet?

Answer 34

Apodia

Question 35

What term is used for the absence of both hands and feet?

Answer 35

Acheriopodia

Question 36

What term is used for the absence of all the digits on a limb?

Answer 36

Adactyly

Question 37

What term is used for the complete absence of one or more limbs?

Answer 37

Amelia Ectromelia

Question 38

What term is used for elongated digits?

Answer 38

Arachnodactyly

Question 39

What term is used for shortened digits?

Answer 39

Brachydactyly

Question 40

What term is used for flexion contracture of a finger (often fourth or fifth), which cannot be fully extended?

Answer 40

Camptodactyly

Question 41

What term is used for the curving of the fifth finger toward the fourth?

Answer 41

Clinodactyly

Question 42

What term is used for the absence of the pre or postaxial structure of a limb?

Answer 42

Hemimelia

Question 43

What term is used for the absence of a limb?

Answer 43

Meromelia

Question 44

What term is used for the absence of any number of fingers or toes?

Answer 44

Oligodactyly

Question 45

What term is used for the absence of proximal limb structures?

Answer 45

Phocomelia

Question 46

What term is used for the presence of extra digits or parts of digits?

Answer 46

Polydactyly

Question 47

What term is used for the absence of the central components of the hand or foot?

Answer 47

Slit hand or foot

Question 48

What term is used for the fusion of digits?

Answer 48

Syndactyly

Question 49

What term is used for the fusion of bones and intervening soft tissue?

Answer 49

Synostosis

Question 50

What term is used for a thumb with 3 rather than 2 phalanges?

Answer 50

Triphalangeal thumb