Epiphyses

Epiphyses

The epiphyses are the rounded ends of long bones in the human body. They are critical in the development and growth of bones, particularly during childhood and adolescence. This article will explore the structure, function, and clinical significance of epiphyses.

Structure

Epiphyses are located at the ends of long bones, such as the femur, humerus, and tibia. Each epiphysis is covered with articular cartilage, which reduces friction and absorbs shock in the joints. Beneath the cartilage, the epiphysis consists of a network of trabecular bone, also known as spongy bone, which provides structural support and houses the bone marrow.

The epiphysis is separated from the main shaft of the bone, known as the diaphysis, by the epiphyseal plate (or growth plate) in children and adolescents. This plate is a layer of hyaline cartilage where bone growth occurs. In adults, the epiphyseal plate is replaced by the epiphyseal line once growth has ceased.

Function

The primary function of the epiphyses is to facilitate joint movement and bone growth. The articular cartilage allows for smooth movement of the joints, while the epiphyseal plate is crucial for longitudinal bone growth. During growth, new cartilage is continuously formed and ossified, contributing to the lengthening of the bone.

Development

Epiphyses develop through a process called endochondral ossification. This process begins with the formation of a cartilage model, which is gradually replaced by bone tissue. The ossification of the epiphyses occurs after the diaphysis, and the timing of this process varies among different bones and individuals.

Clinical Significance

Growth Disorders

Disorders of the epiphyses can lead to growth abnormalities. Conditions such as achondroplasia and epiphyseal dysplasia affect the development and function of the epiphyseal plate, resulting in disproportionate growth and skeletal deformities.

Fractures

Epiphyseal fractures, also known as Salter-Harris fractures, are common in children and adolescents. These fractures can disrupt the growth plate, potentially leading to growth disturbances if not properly treated.

Osteoarthritis

Degeneration of the articular cartilage covering the epiphyses can lead to osteoarthritis, a condition characterized by joint pain and stiffness. This is more common in older adults and can significantly impact mobility and quality of life.

See Also

• Bone anatomy
• Skeletal system
• Cartilage

References

• Gray, H. (1918). Anatomy of the Human Body. Philadelphia: Lea & Febiger.
• Standring, S. (2020). Gray's Anatomy: The Anatomical Basis of Clinical Practice. 42nd Edition. Elsevier.