Principles

Question 0

When is conceptus

Answer 0

Fertilisation till end of week 3

Question 1

When is the embryonic period and what is it?

Answer 1

First 8 weeks after fertilisation after which all organs will be present

Question 2

During which week is the developing child known as an embryo?

Answer 2

Week 4 till end of week 8

Question 3

When is the developing child referred to as a foetus?

Answer 3

Week 9 till birth

Question 4

What is gametogenesis? And what are the names of the products made?

Answer 4

Germ cell formation.
Oocyte (egg)
Spermatozoa (sperm)

Question 5

What is cleavage? And what does it go on to form?

Answer 5

Period if rapid cell division.

Forming morula that then becomes a blastocyst

Question 6

What 4 things happen during the foetal period?

Answer 6

Growth and weight gain
Tissues mature and become functional
Overt sexual differentiation
Bone laid down, connections made in CNS

Question 7

What is apoptosis?

Answer 7

Programmed cell death

Question 8

Define differentiation

Answer 8

Change in appearance/structure; adoption of new function (specialisation)

Question 9

Definite induction

Answer 9

Ability of one cell type to cause another to differentiate

Question 10

Define hypertrophy

Answer 10

Increase in dimension with no increase in cell number

Question 11

Define hyperplasia

Answer 11

Increase in cell number with an increase in dimension

Question 12

Define compaction

Answer 12

Decrease in cell mass with decrease in dimension

Increase in cell number with no increase in dimension

Question 13

Define epiginetic

Answer 13

Preferential expression of either the maternal or the paternal copy of a gene

Question 14

What does folding/rotation do?

Answer 14

Gives the embryo it’s 3D form and allows the formation of completely organ structures

Question 15

Where does fertilisation take place?

Answer 15

In the ampulla

Question 16

What are the steps involved in fertilisation?

Answer 16

Sperm binds with zona pellucida glycoprotein.
Acrosomal enzymes release from sperm head - the sperm digests it’s way into the egg
Egg and sperm plasma membrane fuse
This triggers formation of fertilisation membrane

Question 17

Name the normal sites for implantation

Answer 17

Middle or upper dorsal uterine wall

Question 18

Name the abnormal sites for implantation

Answer 18

Ovary, ampulla, uterine tube, lower part of uterus, cervix or peritoneum

Question 19

What are the three layers formed in gastrulation?

Answer 19

This is the formation of germ layers -
Ectoderm
Mesoderm
Endoderm

Question 20

What do the germ layers made in gastrulation become?

Answer 20

Ectoderm - epidermis of skin, nervous system
Mesoderm - becomes subdivided into 3 parts
Endoderm - lining of gut tube
- lining of respiratory tract

Question 21

What 3 parts does the mesoderm get subdivided into and what do these form?

Answer 21

Paraxial - axial Skelton, parts of dermis
Intermediate - urogenital system
Lateral plate - lining of body wall, most of dermis, parts of limbs, cardio system

Question 22

What does lateral folding do?

Answer 22

Creates the thoracic and abdominal cavities and closes fore and hind gut

Question 23

What does cranial folding do?

Answer 23

Forms the foregut and defines the thoracic cavity

Question 24

What does caudal folding do?

Answer 24

Forms hindgut, anus and umbilical cord

Question 25

Name the 3 types of embryo folding

Answer 25

Lateral, cranial and caudal

Question 26

What happens in the 3rd month of foetal development?

Answer 26

Limbs lengthen | Sex can be determined by external genitalia

Question 27

What happens in months 4 and 5 of foetal development?

Answer 27

Rapid increase in length

Question 28

What happens between month 6 and birth in foetal development?

Answer 28

Rapid increase in weight

Question 29

What are the 4 causes of birth defects?

Answer 29

Unknown Genetic factors Environment Multifactorial

Question 30

In what week does the heart begin to develop?

Answer 30

Week 4

Question 31

What are atrial septal defects?

Answer 31

Defects of one or both of the atrial septae

Question 32

What are ventricular septal defects?

Answer 32

Muscular defects - most common and least severe | Membranous defects - relatively uncommon, very severe

Question 33

What happens in transposition of the great vessels?

Answer 33

Aorta exits right ventricle Pulmonary trunk exist left ventricle Resulting in deoxygenated blood being pumped around the body

Question 34

What are the four components of tetralogy of fallot?

Answer 34

Pulmonary stenosis Hypertrophy of right ventricle Ventricular septal defect Over-riding aorta