| Disorder | Defect | Timing | | :--- | :--- | :--- | | | Failure of vertebral arch closure (sclerotome defect) | Week 4 | | Congenital torticollis | Fibrosis of one sternocleidomastoid muscle (myotome) | Late fetal | | Osteogenesis imperfecta | Mutations in COL1A1/COL1A2 (collagen defect) | Genetic | | Fibrodysplasia ossificans progressiva | Heterotopic bone formation (ACVR1 mutation) | Postnatal | | Amelia/Meromelia | Failure of limb bud formation (due to thalidomide or genetics) | Weeks 4–6 |
Blood vessels invade the center, bringing osteoblasts to replace cartilage with bone.
Muscle development involves the differentiation of myoblasts (muscle precursor cells) into functional muscle fibers.
Around the eighth week, blood vessels penetrate this cartilage, bringing in osteoblasts (bone-building cells). They begin replacing the soft cartilage with hard minerals, a process that won't fully finish until your mid-20s.
| Disorder | Defect | Timing | | :--- | :--- | :--- | | | Failure of vertebral arch closure (sclerotome defect) | Week 4 | | Congenital torticollis | Fibrosis of one sternocleidomastoid muscle (myotome) | Late fetal | | Osteogenesis imperfecta | Mutations in COL1A1/COL1A2 (collagen defect) | Genetic | | Fibrodysplasia ossificans progressiva | Heterotopic bone formation (ACVR1 mutation) | Postnatal | | Amelia/Meromelia | Failure of limb bud formation (due to thalidomide or genetics) | Weeks 4–6 |
Blood vessels invade the center, bringing osteoblasts to replace cartilage with bone. development of the musculoskeletal system
Muscle development involves the differentiation of myoblasts (muscle precursor cells) into functional muscle fibers. | Disorder | Defect | Timing | |
Around the eighth week, blood vessels penetrate this cartilage, bringing in osteoblasts (bone-building cells). They begin replacing the soft cartilage with hard minerals, a process that won't fully finish until your mid-20s. They begin replacing the soft cartilage with hard