Differentiation of the Ectoderm

These flashcards cover essential concepts from the differentiation of the ectoderm, focusing on the development of the central nervous system and epidermis.

What structures make up the central nervous system (CNS)?

The CNS is made up of the brain and spinal cord.

What are the main regions formed during the differentiation of the neural tube?

The neural tube differentiates into various regions including the brain and spinal cord.

What are the two types of neurulation involved in the formation of the neural tube?

Primary neurulation and secondary neurulation.

How does primary neurulation occur?

In primary neurulation, surrounding cells direct the neural plate cells to proliferate, invaginate, and pinch off from the surface to form a hollow tube.

What occurs during secondary neurulation?

The neural tube arises from a solid cord of cells that sinks into the embryo and subsequently hollows out to form a tube.

Which vertebrates primarily utilize secondary neurulation?

Fishes exclusively use secondary neurulation.

How do birds differentiate in their neural tube formation?

Birds use primary neurulation for the anterior portion of the neural tube and secondary neurulation for the posterior part.

What three levels of differentiation occur in the neural tube?

Differentiation occurs at the gross anatomical level, tissue level, and cellular level.

What do neuroepithelial cells differentiate into?

They differentiate into various types of nerve cells (neurons) and supportive cells (glia).

What are the three primary vesicles formed in the developing brain?

Forebrain (prosencephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon).

What is the role of the optic vesicle in lens development?

The optic vesicle activates lens-forming ability of the head ectoderm and positions the lens relative to the retina.

What are the components of the vertebrate eye?

The vertebrate eye includes the lens, iris, cornea, vitreous chamber, sclera, retina, and optic nerve.

What is the purpose of the outer layer of the optic cup?

The outer layer produces melanin pigment and becomes the pigmented retina.

How is the basal layer of epidermis structured in vertebrates?

The basal layer forms a germinal epithelium that gives rise to all skin cells.

What does the Malpighian layer consist of?

It consists of the periderm and the basal layer.

What happens to keratinocytes in the granular layer of the epidermis?

Keratinocytes begin to differentiate and migrate outward to form the cornified layer.