Embryology (Gastrulation)

Question 1

At what stage does Gastrulation occur?

Answer 1

Embryonic development

Question 2

Gastrulation process?

Answer 2

Blastula (single layer) into a Gastrula (multi-layer)

Question 3

How does Gastrulation start /how is the process initiated?

Answer 3

With the Primitive Streak formation

Question 4

Where does gastrulation takes place in Poultry?

Answer 4

1st day of incubation

Question 5

In both poultry and mammals, what is the end result of Gastrulation process?

Answer 5

Germ cell layer formation/Blastodermic layer formation
(ectodermic/endodermi/mesodermic)

Question 6

Which are the 3 Germ Cell layers /Blastodermic layers form post-Gastrulation?

Answer 6

Ectoderm (most external- nervous tissue), Endoderm (most internal), Mesoderm (middle- muscle+ connective tissue)

Question 7

Gastrulation in Mammals and Poultry occurs at (time wise) ?

Answer 7

Mammals- end of 2nd week; Poultry-Incubation

Question 8

What is a Primitive Streak ; where is it found?

Answer 8

Elongated grp of cells, which develop in embryo mesoderm

Question 9

The epiblast turn to what in gastrulation?

Answer 9

Ectoderm

Question 10

The Hypoblast turn to what in gastrulation?

Answer 10

Endoderm

Question 11

What are migrating cells; what do they form?

Answer 11

Fusion of epiblast + hypoblast ; migrate to middle forming the Mesoderm

Question 12

What is Ganglia?

Answer 12

Nervous tissue mass

Question 13

What are the derivatives of the ectoderm?

Answer 13

Neural tube(Brain/Spinal chord)
Neural crest (Peripheral nervous system)
Extraembryonary ectoderm (epidermis/Chorion/Amnios)

Question 14

The Embryonary Ectoderm and Extraembryonary Ectoderm give rise to what structures?

Answer 14

Emb.E- skin, epidermis (cutaneous annexes); Ect.E- chronion + amnions

Question 15

What are the Mesoderm derivatives?

Answer 15

Notochord; Paraaxial Mesoderm, Intermediate Mesoderm, Lateral Plate

Question 16

Notochord forms the?

Answer 16

Primitive Axis

Question 17

The Paraaxial Mesoderm is formed by what?

Answer 17

Somites

Question 18

Somites consist of the following sub divisions:

Answer 18

Myotome (skeletal muscle)
Sclerotome (skeleton and joints)
Dermatome (Skin/subcutaneous tissue)

Question 19

The Urogenital system is formed by what cells?

Answer 19

Neuphroton cells + Gonadal cells (intermediate mesoderm)

Question 20

What gives rise to the Intraembryonic Cellum?

Answer 20

The lateral Plate in the mesoderm

Question 21

Lateral plate sub sections?

Answer 21

Somatopleura and Splachnopleura –> form pleura

Question 22

The somatopleura is found where and gives rise to what?

Answer 22

Top part of lateral plate; gives rise to: amion + chronion and pleura lining pleuricardial. Helps amino acid+ yolk + allantois formation

Question 23

The splachnopleura is found where and gives rise to what?

Answer 23

Bottom part of lateral plate; gives rise to: circulatory system + connective tissue + gut smooth muscle.

Question 24

What consists the endoderm?

Answer 24

Internal Blastodermic cavity

Question 25

What does the Internal blastodermic cavity give rise to?

Answer 25

Respiratory system, digestive system, annex glands (liver + pancreas). Helps form: allantoides + vitelline vesicle + urinary bladder.

Question 26

What happens post Gastrulation process?

Answer 26

Body shape aquisiton

Question 27

When do the embryo and annexes separate?

Answer 27

During the post gastrulation process period. Formation of clear embryo occur

Question 28

When clear embryo is formed what occurs/structural occuraces?

Answer 28

Clear Embryo; the rest of annexes (vitelline vesicle + allantoides) surround embryo

Question 29

At what stage does limb development and head and truck separation occur?

Answer 29

At post gastrulation

Question 30

Where does gastrulation takes place in mammals?

Answer 30

2nd week of pregnancy