Vetan Topic 2 and 4

Question 1

What are the five processes that take place during early developmental stages?

Answer 1

1. growth
2. morphogenesis
3. patterning
4. cytodifferentiation
5. tissue interaction

Question 2

It refers to the increase in the number or size of cells that results in the increase in mass of the organism.

Answer 2

growth

Question 3

Process which refers to the entire group of processes that mold the external & internal
configuration of the embryo. This involves a change in the shape or location or even
death of a cell or tissue.

Answer 3

morphogenesis

Question 4

elongation of epithelial cells. Ex. elongation of epiblasts during gastrulation.

Answer 4

epithelial expansion

Question 5

programmed degeneration & eventual death of
cells in areas called necrotic zones

Answer 5

normal cell death or apoptosis

Question 6

outward folding or outpocketing of the epithelium. Ex. development of optic vesicle from neural tube

Answer 6

evagination

Question 7

downward migration of epithelium with secondary, tertiary branches given off from the main branch. Ex. development of lung and duct system
of major salivary glands.

Answer 7

budding and branching

Question 8

separation of an invaginated epithelium from the original epithelium; the second stage in more complex morphogenetic reorganization. Ex.
formation of neural tube

Answer 8

vesicle formation

Question 9

infolding or depression of epithelium to form a pit or groove; often the first stage in more complex morphogenetic reorganization. Ex. formation of neural tube

Answer 9

invagination

Question 10

focal thickening of surface ectoderm, often in response to an underlying mesenchymal aggregation

Answer 10

placode formation

Question 11

grouping of mesenchymal cells to form a densely
packed subpopulation within a mesenchymal tissue. Ex. formation of enamel organ
and vertebra.

Answer 11

mesenchymal aggregation

Question 12

migration of epithelial cells to the underlying area to form mesenchymal cells. Ex. formation of mesoderm

Answer 12

delamination

Question 13

is the establishment of invisible blueprint of cell
subpopulations that serves as a guide in the formation of a particular tissue or organ

Answer 13

patterning

Question 14

complex tortuous process by which each cell or cell line attains and expresses a stable phenotype or a process by which a cell becomes specialized
and the final product is a differentiated cell

Answer 14

cytodifferentiation

Question 15

is a process in which the presence of one tissue
or structure induces or causes the development of another tissue or structure

Answer 15

tissue interaction or tissue induction

Question 16

period or the time during which each organ system in the body is being formed and obligatory inductive tissue interactions and morphogenesis are occurring

Answer 16

critical period

Question 17

genes that cause congenital defects

Answer 17

deleterious genes

Question 18

Causes of congenital malformation or defect?

Answer 18

1. Hereditary or genetic factors
2. Environmental factors

Question 19

What are the teratogens transmitted directly to the embryo through the maternal-placental fetal interaction? (4)

Answer 19

1. radiation
2. viruses
3. steroid hormones
4. low molecular weight compounds

Question 20

induces birth defects during closure of neural tube resulting in eye, brain and heart defects

Answer 20

hypervitaminosis A

Question 21

occurs in the epiblast of the embryonic disk, a
relatively small area of the blastocyst when compared to the extraembryonic trophoblast

Answer 21

formation of the primitive streak

Question 22

defines the longitudinal axis of the embryo and indicates the start of germ layer formation.

Answer 22

primitive streak

Question 23

The primitive streak presents at its
cranial end the primitive (Hensen’s) node that presents a central deep hole called

Answer 23

primitive pit

Question 24

What is the process of epiblast migration to form endoderm and mesoderm is called?

Answer 24

involution

Question 25

closely adjacent to the overlying ectoderm of the embryonic disk and the trophoblast

Answer 25

somatic mesoderm

Question 26

closely related to the underlying embryonic endoderm and hypoblast

Answer 26

splanchnic visceral mesoderm

Question 27

somatic mesoderm and the embryonic ectoderm and trophoblast eventually combine to form the?

Answer 27

somatopleure

Question 28

It is the central pale oval area of blastoderm

Answer 28

area pellucida

Question 29

the dark area peripheral to the area pellucida

Answer 29

area opaca

Question 30

What is the rod-shaped aggregate of epiblast cells located cranial to the primitive streak?

Answer 30

notochord

Question 31

What is the ultimate fate of the notochord?

Answer 31

nucleus pulposus of intervertebral discs

Question 32

In birds, when the primitive streak has completely regressed, the epiblast cells on the surface of the embryonic disk constitute what germ layer?

Answer 32

ectoderm

Question 33

Five characteristics of neurulation.

Answer 33

i. Formation of the central nervous system ii. Formation of the head process iii. The initial development of the gut iv. Formation of somite v. Initial development of the heart

Question 34

it is the result of the thickening of the surface ectodermal cells along the dorsal midline of the embryonic disk overlying the notochord

Answer 34

neural plate

Question 35

neural plate becomes depressed to form _______ and the edges of the neural plate becomes raised or elevated to form NEURAL FOLDS

Answer 35

neural groove

Question 36

first part of the gut tube that is formed is the foregut, whose most rostral tip eventually becomes the?

Answer 36

pharynx

Question 37

What is the future of the foregut?

Answer 37

pharynx

Question 38

These are blocks of mesoderm derived from paraxial mesoderm located just lateral to the notochord

Answer 38

somites

Question 39

less-developed somites

Answer 39

somitomeres

Question 40

somites which forms skeletal musculature.

Answer 40

myotome

Question 41

somites which forms most of the axial skeleton: vertebrae, ribs and bone of the skull

Answer 41

sclerotome

Question 42

somites that migrates to form the skin dermis

Answer 42

dermatome

Question 43

cardiogenic mesoderm on either side forms endocardial tube and the two endocardial tubes fuse to form a single?

Answer 43

cardiac tube

Question 44

The fused endocardial tubes and cardiogenic plates become the ______ which is composed of epimyocardium

Answer 44

cardiac tube

Question 45

it holds the cardiac tube in place

Answer 45

dorsal mesocardium

Question 46

The fused ventral parts of splanchnic mesoderm become the _______ ________, which degenerates almost as soon as it is formed, giving way for the R and L pericardial coeloms to fuse and communicate.

Answer 46

ventral mesocardium

Question 47

subcephalic pocket created during the formation of the head process forms bilateral margins designated as the?

Answer 47

lateral body folds