Metaphysis

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Metaphysis

The metaphysis is the narrow portion of a long bone between the epiphysis and the diaphysis. It contains the epiphyseal plate (growth plate), which is the area of growing tissue near the ends of the long bones in children and adolescents. The metaphysis is highly vascular and is the site where bone growth occurs during childhood and adolescence.

Structure

The metaphysis is composed of trabecular bone (spongy bone) and is rich in bone marrow. It is a critical region for the growth and development of long bones. The epiphyseal plate within the metaphysis is made of hyaline cartilage and is responsible for the longitudinal growth of bones. As a person matures, the epiphyseal plate ossifies and becomes the epiphyseal line.

Function

The primary function of the metaphysis is to support the growth of long bones. The osteoblasts in the metaphysis are responsible for the formation of new bone tissue, which contributes to the lengthening of the bone. The metaphysis also plays a role in the repair of bone fractures.

Clinical Significance

The metaphysis is a common site for certain types of bone diseases and conditions, such as osteosarcoma, which is a type of bone cancer that typically occurs in the metaphysis of long bones. Metaphyseal dysplasia is another condition that affects the metaphysis, leading to abnormal bone growth and development.

Related Structures

• Epiphysis
• Diaphysis
• Epiphyseal plate
• Trabecular bone
• Bone marrow
• Osteoblast
• Hyaline cartilage

See Also

• Bone
• Skeletal system
• Osteosarcoma
• Metaphyseal dysplasia