What is the first stage of embryonic development?

The process of prenatal development occurs in three main stages. The first two weeks after conception are known as the germinal stage, the third through the eighth week is known as the embryonic period, and the time from the ninth week until birth is known as the fetal period.

Which organs develop first in embryonic?

The heart is the first organ to form during development of the body. When an embryo is made up of only a very few cells, each cell can get the nutrients it needs directly from its surroundings.

Which part of the skeleton develops first?

notochord
The early development of the skeletal system begins in the third week after conception with the formation of the notochord (a rod-like structure along the back of the embryo that later becomes the spine, spinal cord, and brain), followed in the fourth week by the first signs of arms and legs.

What are the stages involved in embryology?

During the pre-embryonic period, there are several important phases of human embryology that lead up to and follow sex determination: fertilization, cleavage, gastrulation, and organogenesis fertilization occur when there’s a successful union between two gametes.

What are the 6 stages of embryonic development in order?

Contents

• Germinal stage. 1.1 Fertilization. 1.2 Cleavage. 1.3 Blastulation. 1.4 Implantation. 1.5 Embryonic disc.
• Gastrulation.
• Neurulation.
• Development of organs and organ systems.

What is the correct order of embryonic development?

Hence the correct answer is ‘C’ i.e, Zygote-morula-blastula-gastrula-embryo. Note:All cleavage divisions are mitotic and resultant daughter cells are blastomeres.

Do muscles form before bones?

The development of bone and muscle begins at the fourth gestational week, when the paraxial mesoderm differentiates into somites; the latter gives rise to sclerotomes and dermomyotomes. Sclerotomes form the vertebra and the ribs, whereas myotomes form the majority of the muscular system.

How does bone formation begin?

Bone development begins with the replacement of collagenous mesenchymal tissue by bone. Generally, bone is formed by endochondral or intramembranous ossification. Intramembranous ossification is essential in the bone such as skull, facial bones, and pelvis which MSCs directly differentiate to osteoblasts.

What is the first stage of embryonic development quizlet?

1st stage. After fertilization, the sperm and egg become a zygote, which then begins a number of cell divisions called this. 2nd stage. The blastula is formed four days after conception.