PLZ HELP! Fill in the blank with one of the answer choices below. 1. The inner cavities of bones are filled with .

2. The hard, outside part of a bone is called tissue.

3. The bones are operated by to produce body movements

4. The spongy, inner tissue of a bone is called tissue.

5. Red blood corpuscles are formed in the marrow of bones.

a. bone marrow
b. compact or dense
c. cancellous
d. bone
e. muscle

1. The inner cavities of bones are filled with A. Bone Marrow.

2. The hard, outside part of the bone is called B. Compact or Dense tissue.

3. The bones are operated by E. Muscle to produce body movements.  

4. The spongy, inner tissue of a bone is called C. Cancellous tissue.

5. Red blood corpuscles are formed in the D. Bone Marrow of bones.

Explanation:

1. Bone marrow is a soft tissue filling the cavities inside the bones. The two types of bone marrow that exist are the red bone marrow, which produces the blood cells, and the yellow bone marrow. Bone marrow also produces platelets.

2. Compact bone is the solid, hard outside part of the bone. It looks like ivory and is extremely strong. Holes and channels run through it, carrying blood vessels and nerves.

3. The bones of the skeletal system serve to protect the body's organs, support the weight of the body, and give the body shape, while the muscles of the muscular system attach to these bones, pulling on them to allow for movement of the body. Muscles are  masses of tough, elastic tissue that pull our bones when we move. Together, our bones, muscles, and joints — along with tendons, ligaments, and cartilage — form our musculoskeletal system and enable us to do everyday physical activities.

4. Cancellous tissue, also known as cancellous bone, spongy bone or trabecular bone, is characterized by its spongy, porous, honeycomb-like structure and is typically found at the ends of long bones. Cancellous tissue makes up about 20% of the human skeleton, providing structural support and flexibility without the weight of compact bone.

5. Red blood cells are formed in the red bone marrow of bones. Stem cells in the red bone marrow are called hemocytoblasts. They give rise to all of the formed elements in blood.