Embryo: Germ Layer Derivatives Flashcards
Where can you find ectodermal germ layers?
- Epidermis
- CNS
- Neural crest - gives rise to a variety of structures
- Sense organs placodes
Generally, what are the ectodermal derivatives?
Structures that maintain contact with the external environment
What does the epidermis become?
Skin and epidermal derivatives
What does the neural plate become?
Neural folds
What does the neural fold become?
Neural tube
What does the neural tube give rise to?
CNS
What is the neural crest?
Surface ectoderm that gives rise to a variety if structures such as:
- Spinal root ganglia
- Schwann Cells (produce myelin in PNS)
- Pia mater and arachnoid layer
- Melanocytes (brown pigment in skin)
- Craniofacial bones
Generally, what are the mesodermal derivatives?
CT, muscle (skeletal, smooth, and cardiac), circulatory system, kidneys, and gonads
What are the 3 divisions of mesoderm?
- Paraxial mesoderm
- Intermediate mesoderm
- Lateral mesoderm
What is the paraxial mesoderm?
Develop somites which form skin, bone, and muscle
- foundation for the axial skeleton
What do the intermediate mesoderm become?
Kidneys and gonads
What does somo mean?
Body
What layers do the lateral plate mesoderm form?
- Somatic (parietal) mesoderm
2. Splanchnic (visceral) mesoderm
What does the somatic (parietal) mesoderm do?
Lines body wall
What does the splanchnic (visceral) mesoderm do?
Covers viscera
