What is the mechanism of marrow cavity enlargement in a long bone?
A) There is no mechanism; once formed, the marrow cavity does not change in size.
B) As bone matrix is added to the external surface, osteoclasts remove matrix in the center of the bone to enlarge the cavity.
C) Blood vessels entering the marrow cavity enlarge it by eroding away the inner surface of the bone.
D) The bone marrow cavity only increases in length, as the epiphyseal plates move apart.
E) None of the answers are correct.

Question

Quizplus · Accepted Answer

As a long bone grows, bone matrix is added to the external surface by osteoblasts. In order for the bone to maintain an appropriate weight and proportion, osteoclasts within the center of the bone remove matrix, which enlarges the marrow cavity. This allows for increased blood cell production in the bone marrow.

What Is the Mechanism of Marrow Cavity Enlargement in a Long