Describe the structural differences between the diaphysis and the epiphysis of a long bone.
The diaphysis is the shaft of a long bone, composed primarily of thick compact bone and containing a medullary cavity filled with yellow marrow in adults. The epiphyses are the wider ends of the bone, consisting of spongy bone surrounded by a thin layer of compact bone and covered with articular cartilage at joint surfaces.
What is the function of the epiphyseal plate, and what does it become after puberty?
The epiphyseal plate, also known as the growth plate, is a line of hyaline cartilage in the metaphysis that allows for bone lengthening during growth. After puberty, it is replaced by the epiphyseal line, indicating that bone growth in length has ceased.
How do blood vessels and nerves enter the diaphysis of a long bone, and how does this differ from their entry into the metaphysis and epiphysis?
Blood vessels and nerves enter the diaphysis through a single, macroscopic hole called the nutrient foramen, allowing the nutrient artery, vein, and nerves to supply the bone and marrow. In the metaphysis and epiphysis, multiple smaller foramina allow for the entry of blood vessels and nerves.
What is the main structural difference between the diaphysis and the epiphysis of a long bone?
The diaphysis is the shaft made mostly of thick compact bone with a medullary cavity, while the epiphyses are the wider ends made of spongy bone surrounded by a thin layer of compact bone and covered with articular cartilage.
What type of bone tissue primarily composes the diaphysis, and what does it contain in adults?
The diaphysis is primarily composed of compact bone and contains a medullary cavity filled with yellow marrow in adults.
Where is the epiphyseal plate located, and what is its function?
The epiphyseal plate is located in the metaphysis between the diaphysis and epiphysis, and it allows for bone lengthening during growth.
What happens to the epiphyseal plate after puberty?
After puberty, the epiphyseal plate is replaced by the epiphyseal line, indicating that bone growth in length has stopped.
How do blood vessels and nerves enter the diaphysis of a long bone?
Blood vessels and nerves enter the diaphysis through a single, macroscopic hole called the nutrient foramen.
How does the entry of blood vessels and nerves into the metaphysis and epiphysis differ from the diaphysis?
In the metaphysis and epiphysis, multiple smaller foramina allow for the entry of blood vessels and nerves, unlike the single nutrient foramen in the diaphysis.
What is the function of articular cartilage on the epiphysis of a long bone?
Articular cartilage covers the epiphysis at joint surfaces to provide a smooth, soft surface that reduces friction and allows bones to glide over each other easily in joints.