embryonic skeletal system development

Definition

Target type: biologicalprocess

The process, occurring during the embryonic phase, whose specific outcome is the progression of the skeleton over time, from its formation to the mature structure. [GOC:dph, GOC:dsf, GOC:jid, GOC:tb, PMID:16049113]

Embryonic skeletal system development is a complex and intricate process that involves a tightly orchestrated interplay of multiple cellular and molecular events. It begins with the formation of the mesoderm, a germ layer that gives rise to skeletal tissues. Within the mesoderm, specific populations of cells differentiate into chondrocytes, the cells responsible for forming cartilage, the precursor to bone.

Cartilage formation, known as chondrogenesis, involves the condensation of mesenchymal cells, followed by the expression of chondrogenic genes that regulate the synthesis of extracellular matrix molecules, primarily collagen type II and aggrecan. These molecules create a specialized extracellular environment that supports chondrocyte proliferation and differentiation.

As the embryo grows, the cartilaginous skeletal model undergoes a process called endochondral ossification, where cartilage is gradually replaced by bone. This process starts with the formation of a primary ossification center within the diaphysis, or shaft, of long bones. Blood vessels invade the cartilage, bringing in osteoblasts, bone-forming cells. Osteoblasts deposit bone matrix, initially forming woven bone, which is later remodeled into lamellar bone.

Simultaneously, secondary ossification centers develop in the epiphyses, or ends, of long bones. These centers expand towards the diaphysis, leaving a thin layer of cartilage, the epiphyseal growth plate, responsible for longitudinal bone growth.

Throughout this process, skeletal development is regulated by a complex interplay of signaling pathways, including the Wnt, BMP, and FGF pathways. These pathways are activated by various factors, including growth factors, hormones, and mechanical forces.

The development of the skeletal system is a dynamic process that continues after birth, with bone growth and remodeling occurring throughout life. This ensures that the skeleton can support the body's weight and allow for movement.

During postnatal life, bone growth is primarily controlled by growth hormone, while bone remodeling is regulated by parathyroid hormone, calcitonin, and other factors. This intricate regulation ensures that the skeletal system remains strong and adaptable throughout the lifespan.'
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Proteins (6)

Compounds (137)