Question

complete the following:

1. distinguish between the locations and tissues of the periosteum and those of the endosteum.
2. what structural differences did you note between compact bone and spongy bone?
3. how are these structural differences related to the locations and functions of these two types of bone?
4. from your observations, how does the marrow in the medullary cavity compare with the marrow in the spaces of the spongy bone?

Explanation:

1. The periosteum is a dense - fibrous membrane covering the outer surface of bones (except at joint surfaces), composed of connective tissue. The endosteum lines the inner surface of the medullary cavity and is a thin connective - tissue membrane.
2. Compact bone is dense and solid - looking, with osteons (Haversian systems) as its structural units. Spongy bone has a lattice - like appearance with trabeculae and contains red marrow in its spaces.
3. Compact bone is located on the outer layer of bones, providing strength and support for weight - bearing and protection of internal organs. Spongy bone is located in the interior of bones, near the epiphyses, and is lighter, which helps reduce the weight of the skeleton while still providing some strength and also housing red marrow for hematopoiesis.
4. The marrow in the medullary cavity is mainly yellow marrow (fatty tissue) in adults, which stores energy. The marrow in the spaces of spongy bone is red marrow, which is responsible for producing blood cells.

Answer:

1. Periosteum covers outer bone (except joints), connective tissue. Endosteum lines inner medullary cavity, thin connective tissue.
2. Compact bone: dense, has osteons. Spongy bone: lattice - like, has trabeculae and red marrow.
3. Compact bone: outer, for strength/protection. Spongy bone: inner, lighter, for hematopoiesis.
4. Medullary cavity marrow: mainly yellow (fatty, energy storage). Spongy bone marrow: red (blood - cell production).