How do compact and spongy bones differ?

Answer 1

Spongy Bone has more surface area, but it is weaker and not as dense as compact bone.

Compact Bone is the tough outer layer of bone while spongy bone is the porous bone where the red and yellow marrow is.

Spongy is softer bone, with holes in it. It is found inside the bone. It is lighter than compact bone.

Compact bone is generally on the outer edges of bone. it is composed of multiple osteon units that are bunched closely together like stacked logs and, thus, is good at bearing weight in the long direction. Spongy bone is generally on the inside of compact bone. Individual osteon-like struts (called trabeculae) branch in many directions and interconnect. Thus, there are spaces created where red marrow exists. This kind of bone is good at handling stress from multiple directions and is lighter weight.

Spongy bone can appear yellow because it has some fat in it, and it is possible to see small holes in spongy bone. Compact bone is usually white.

Also, spongy bone is not long (like the wrist) most irregular and flat bones are formed from spongy bone tissue. Compact bone is usually long (like a femur).

Compact bone tissue is hard with few open spaces & provides protection and support.Spongy bone tissue is porous with many open spaces

Answer 2

The functional units of compact bone are called osteons. These form concentric layers that are called central canals. The central canals usually run parallel to the length of the bone and carry nutrients. All osteons in compact bone are aligned exactly the same and therefore makes compact bone very strong (when stressed along the long axis of the bone). Compact bone is very dense compared to spongy bone. It is located in the middle (diaphysis) of long bones. It can also has yellow marrow, which is mostly adipose (fat) tissue storage.

Spongy bone (located at the ends or epiphysis) does not have osteons. There is instead a spread out network of fibers, making it much less dense, more flexible, and reduce the weight of the skeleton. Red marrow is located in this type of bone as well as yellow, depending on the location in the body. Red marrow is responsible for red blood cell production as well as other things.