Organogenesis

Question 0

Summary: (FIGR)

1. _________ and the pre-implantation period - formation of the morula and blastocyst
2. __________
3. __________ - formation of the three germ layers
4. __________ of the 3 week old embryo
   a. Head, tail, neural plate, notochord

Answer 0

1. Fertiliztion
2. Implantation
3. Gastrulation
4. Regioinalization

Question 1

In what period of embryogenesis does organogensis begin?

Answer 1

Somite period

Question 2

If something traumatic or dangerous happens in the first __ weeks of development, you’ll see the development of major congenital anomalies.

Answer 2

8 weeks

Question 3

The notochord induces formation of the _________ ________ (neurulation) in the overlying ectoderm. This then becomes a ________ ________ by active cell proliferation and changes in cell shape.

Answer 3

Neural plate –> Neural groove

Question 4

The neural tube begins closing in the middle and has open ends which are referred to as the ________.

Answer 4

neuropores

Question 5

Which end expands rapidly due to differential growth?

Answer 5

anterior

Question 6

The failure of the posterior neural tube closure.

Answer 6

Spina bifida

Question 7

The failure of anterior neural tube closure.

Answer 7

Anencephaly

Question 8

The failure of the neural tube to close head to tail.

Answer 8

Craniorachischisis

Question 9

Problems with neurulation can be prevented with increase of what in your diet?

Answer 9

folic acid

Question 10

Mesoderm Differentiation:

• Somatopleural includes _________ and _________.
• Splanchnopleural includes _________ and __________.

Answer 10

Somatopleural (mesoderm and ectoderm)

Splanchnopleural (mesoderm and endoderm)

Question 11

The paraxial mesoderm becomes _________, which are transient organs that organize themselves without cell differentiation (primary organs). Also referred to as blocks of mesoderm that are located on either side of the neural tube in the developing vertebrate embryo.

Answer 11

somites

Question 12

The segmental (metamere) partitioning of the spine, the neural tube, the trunk wall, and the ribs depend on what?

Answer 12

the ordered arrangements of the somites

Question 13

The somite consists of what three components?

Answer 13

dermatome, myotome, and sclerotome

Question 14

Which component of the somite forms the connective tissue of the dermis?

Answer 14

dermatome

Question 15

Which component of the somite forms muscle?

Answer 15

myotome

Question 16

Which component of the somite forms skeletal elements of the vertebral column?

Answer 16

sclerotome

Question 17

How many embryonic somites are there?

How many fully formed fetus somites are there?

Answer 17

embryonic (42-44)

fetus (35-37)

Question 18

The somite forms from the _________ mesoderm. Early somites have a central cavity and cells are _________-like. Ventral cells lose this characteristic.

Answer 18

paraxial, epithelial

Question 19

In summary of neurulation:

1. We formed the neural plate into a neural ________.
2. The mesoderm formed _________ and then contributed to the vertebra and muscles.
3. We now need to ________ the embryo.

Answer 19

1. neural tube
2. somites
3. fold

Question 20

Mesodermal Derivatives:

1. vertebrae, dermis, muscles
2. urogenital system (ie. kidney)
3. Lateral Plate Mesoderm
   a. forms somatic lining of the periotonium, muscles of the limbs and body wall
   b. forms muscle of the gut and mesentery

Answer 20

1. Paraxial Mesoderm
2. Intermediate Mesoderm
3. Lateral Plate Mesoderm
   a. Somitopleurae
   b. Splanchnopleurae