Anatomy Bone Composition Part 2

What is the diaphysis?

elongated, usually cylindrical shaft, provides leverage and weight support, compact bone with thin plates of spongy bone extending inward

What is medullary cavity?

hollow cylindrical space within the diaphysis, contains red bone marrow in children, contains yellow bone marrow in adults

What is epiphysis?

expanded region at each end of long bone

Where is the proximal epiphysis?

end of the bone closest to body trunk

Where is the distal epiphysis?

end of bone furthest from trunk

What is the epiphysis composed of?

outer thin layer of compact bone, inner region of spongy bone

What is articular cartilage?

covers the joint surface, thin layer of hyaline cartilage,

What is the function of articular cartilage?

reduces friction, absorbs shock in moveable joints.

What is metaphysis?

region of mature bone between diaphysis and epiphysis

What is the epiphyseal plate?

growth plate, thin layer of hyaline cartilage, is converted to bone over time

What is the function of the epiphyseal plate?

provides for lengthwise bone growth, forms the epiphyseal line when done growing

What is the periosteum?

coverings and linings of bone on the outside

What is the endosteum?

covers all internal surfaces of bone within medullary cavity, incomplete layer of cells, surrounds medullary cavity

What is bone marrow?

soft CT of bone, there are two types

What are the two types of bone marrow?

red and yellow

What is red bone marrow?

it is hemopoietic, located in spongy bone and medullary cavity of long bones in childrens, and skull, vertebrae, ribs, sternum, ossa coxae, proximal epiphyses of humerus and femur in adults

What does hemopoietic mean?

blood cell forming

What is yellow bone marrow?

product of red bone marrow degeneration as children mature, it is a fatty substance, can convert back to red bone marrow

When does yellow bone marrow turn back into red bone marrow?

during severe amemia (condition with reduced red blood cells)