Lecturio 2. Gastrulation and Trilaminar Embryo

Question 1

The process of gastrulation begins with (1)____

The epiblast involutes and creates (2)___

Answer 1

1. the bilaminar embryo.
2. the trilaminar embryo.

Question 2

Epiblast subdivides into ____ (3 categories)

Answer 2

ectoderm, endoderm and mesoderm

Question 3

Epiblast subdivides into ectoderm, endoderm and mesoderm

Set of three different germ cells that differentiate into __

Answer 3

specific and distinct tissues and not others

Question 4

Formation of the Primitive Streak

Bilaminar embryo becomes “polarized” by the ___, where the mouth will form

Answer 4

prechordal plate

Question 5

Formation of the Primitive Streak

Bilaminar embryo becomes “polarized” by the prechordal plate, where ___ will form

Answer 5

the mouth

Question 6

Formation of the Primitive Streak

____ becomes “polarized” by the prechordal plate, where the mouth will form

Answer 6

Bilaminar embryo

Question 7

Formation of the Primitive Streak

Bilaminar embryo becomes ___ by the prechordal plate, where the mouth will form

Answer 7

prechordal plate

Question 8

Formation of the Primitive Streak

On the opposite side of the disc, epiblast cells collapse inward to create ____

Answer 8

the primitive streak.

Question 9

Formation of the Primitive Streak

On the opposite side of the disc,___collapse inward to create the primitive streak.

Answer 9

epiblast cells

Question 10

Formation of the Primitive Streak

The tip of the primitive streak is known as the (1)___, surrounded by the (2)___

Answer 10

1. primitive pit
2. primitive node.

Question 11

Formation of the Primitive Streak

IDENTIFY

Answer 11

1. primitive pit
2. primitive node.

Question 12

Migration through the Primitive Streak

→ IDENTIFY

Answer 12

Question 13

Migration through the Primitive Streak

Cells from the epiblast involute through the (1)____ to fill the space between the epiblast and hypoblast.

→ This middle layer is the (2)___.

Answer 13

1. primitive streak and pit
2. mesoderm

Question 14

Migration through the Primitive Streak

Cells from the epiblast involute through the primitive streak and pit to fill the space between ___

→ This middle layer is the mesoderm.

Answer 14

the epiblast and hypoblast.

Question 15

Migration through the Primitive Streak

Migrating epiblast cells also replace the hypoblast with a germ layer called the (1)___

→ epiblast layer remains but changes name to become the (2)____

Answer 15

1. endoderm
2. ectoderm

Question 16

Migration through the Primitive Streak

igrating epiblast cells also replace ___ with a germ layer called the endoderm

→ epiblast layer remains but changes name to become the ectoderm

Answer 16

the hypoblast

Question 17

Migration through the Primitive Streak

Epiblast cells that move through the primitive pit and migrate straight toward the prechordal plate will become ___

Answer 17

the notochordal process.

Question 18

Migration through the Primitive Streak

Epiblast cells that move through the primitive pit and migrate straight toward ___ will become the notochordal process.

Answer 18

the prechordal plate

Question 19

Migration through the Primitive Streak

____ that move through the primitive pit and migrate straight toward ___ will become the notochordal process.

Answer 19

Epiblast cells

Question 20

Migration through the Primitive Streak

Notochord cells cannot extend past the prechordal plate as the ectoderm and endoderm there are firmly adherent to each other.

→ This area is now called the ____

Answer 20

the prechordal plate

Question 21

Migration through the Primitive Streak

Notochord cells cannot extend past ____ as the ectoderm and endoderm there are firmly adherent to each other. This area is now called the oropharyngeal membrane.

Answer 21

the prechordal plate

Question 22

Migration through the Primitive Streak

Notochord cells cannot extend past the prechordal plate as the ectoderm and endoderm there are firmly adherent to each other. This area is now called the oropharyngeal membrane.

→ A similar area on the other side of the primitive streak is ____

Answer 22

the cloacal membrane. (form the anus,….)

Question 23

Notochord

→ Identify

Answer 23

Question 24

Notochord

Migrating from the epiblast, ____ extends cranially towards the prechordal plate, a hollow notochordal canal is located within.

Answer 24

the notochordal process

Question 25

**Notochord** Migrating from the epiblast, the **notochordal process** extends cranially towards \_\_\_

Answer 25

the prechordal plate, a hollow **notochordal canal** is located within.

Question 26

**Notochord** → IDENTIFY?

Answer 26

Question 27

**Gastrulation and the Trilaminar Embryo** **→** The inferior side of the notochordal process and canal ruptures, creating \_\_\_\_\_

Answer 27

a **notochordal plate**.

Question 28

**Gastrulation and the Trilaminar Embryo** **→** The inferior side of ___ and canal ruptures, creating a **notochordal plate**.

Answer 28

the notochordal process

Question 29

**Gastrulation and the Trilaminar Embryo** **→ Identify**

Answer 29

Question 30

**Gastrulation and the Trilaminar Embryo** **→ Identify**

Answer 30

Question 31

**Gastrulation and the Trilaminar Embryo** **→ Identify**

Answer 31

Question 32

**Gastrulation and the Trilaminar Embryo** The plate then folds together within the mesoderm to form \_\_\_

Answer 32

Question 33

**Gastrulation and the Trilaminar Embryo** The plate then folds together within the ___ to form the **notochord**.

Answer 33

mesoderm

Question 34

**Intraembryonic Mesoderm** Notochord forms from cells, enter the mesoderm on (1)\_\_\_\_ → other cells' fate is determined by their location as they pass through (2)\_\_\_

Answer 34

1. the midline 2. the primitive streak

Question 35

**Intraembryonic Mesoderm** Mesoderm migrate to the cranial and lateral to the prechordal plate to become \_\_\_

Answer 35

**cardiogenic mesoderm**

Question 36

**Intraembryonic Mesoderm** Mesoderm migrate to the ___ (cranial/lateral) and \_\_\_\_(cranial/lateral) to the prechordal plate to become **cardiogenic mesoderm**

Answer 36

1. cranial 2. lateral

Question 37

**Intraembryonic Mesoderm** Mesoderm migrate to the cranial and lateral to ____ to become **cardiogenic mesoderm**

Answer 37

the prechordal plate

Question 38

**Intraembryonic Mesoderm** Cells that enter even more caudally become ___ (4 things)

Answer 38

1. paraxial mesoderm 2. intermediate mesoderm 3. lateral plate mesoderm 4. extraembryonic mesoderm

Question 39

**Intraembryonic Mesoderm** IDENTIFY

Answer 39

Question 40

**Intraembryonic Mesoderm** IDENTIFY

Answer 40