Embryonic Development: Gastrulation and Organogenesis

During which week of embryonic development does gastrulation occur?

What is the process by which cells migrate from the embryoblast to form the germ layers during gastrulation?

What is the process by which tissues differentiate into specific cell types during organogenesis?

During which weeks of embryonic development does organogenesis occur?

What is the result of the gastrulation process?

What is the process by which one tissue influences the development of another during organogenesis?

Embryonic Development

Gastrulation

Definition: The process by which the blastula undergoes a series of complex cellular movements to form the three primary germ layers: ectoderm, mesoderm, and endoderm
Occurs during the third week of embryonic development
Characterized by:
- Invagination: inward movement of cells to form the archenteron (primitive gut)
- Delamination: migration of cells from the embryoblast to form the germ layers
- Epiboly: expansion of the embryoblast to cover the yolk sac
Results in the formation of the gastrula, consisting of the three primary germ layers

Organogenesis

Definition: The process by which the three primary germ layers differentiate and organize to form specific organs and body systems
Occurs during the fourth to eighth weeks of embryonic development
Characterized by:
- Morphogenesis: the process by which tissues and organs take shape
- Histogenesis: the process by which tissues differentiate into specific cell types
- Organ induction: the process by which one tissue influences the development of another
Results in the formation of major organs and body systems, such as the nervous system, circulatory system, and digestive system

Test your knowledge of the complex processes of gastrulation and organogenesis during embryonic development. Learn about the formation of the primary germ layers, organ induction, and the development of major organs and body systems.