It takes about 6 weeks for the fibrocartilage in a fetus to begin developing into bones(ossification.)
The ❌ of long bones is the ❌ centre of ossification. The ❌ occur in the ❌. These are separated by the epiphyseal plate, which is initially cartilaginous but becomes bone later in life.
The process of bone growing in width is called moulding.
During moulding: (Choose ALL CORRECT statements.)
Osteoblasts in the periosteum increase bone width.
Osteoclasts form the medullary cavity.
Osteoblasts in the medullary cavity form the trabeculae.
Osteoclasts increase the width of the periosteum.
In children, the medullary cavity is full of yellow marrow to facilitate the continuous growth, while in adults the medullary cavity is filled with red marrow.
Red marrow is red as it is highly vascularised.
What is epiphyseal fusion?
The calcification of the region between an epiphysis and edge of the medullary cavity.
The ossification of the epiphyseal joint.
The ossification of the epiphyseal plate.
The merging of two regions of bone between the epiphysis and diaphysis.
Bone pathology:
Is an imbalance of osteoclastic and osteoblastic activity.
Is the structure of bones at the cellular level.
Osteoporosis is the weakening of the bone due to porousness, caused by osteoblastic activity overtaking osteoclastic activity.
Weakening of cancellous bone commonly leads to compression fractures.
Which of these is not a cause or contributing factor to risk of osteoporosis?
Menopause (decrease in estrogen)
Lack of exercise
Eating disorders
Early use of steroids
Excess calcium intake
Assign these stages of a fracture with a time frame: A hematoma forms, capillaries growing into it and phagocytes cleaning up debris, almost immediately after 24 hours( almost immediately, after 24 hours ). Chondroblasts form a soft procallus of cartilage, within 3 days within 3 weeks( within 3 days, within 3 weeks ). Osteoblasts ossify the callus into a bony callus, by 6 weeks. by 6 months( by 6 weeks., by 6 months ) Normal activity remodels the bone in the following weeks, or potentially years months( years, months ) until the callus has disappeared (generally in adults.)
Not fixing a fracture results in pseudoarthrosis.
Which fracture has the most potential risk?
Compound fracture
Open fracture
Greenstick fracture