MICROANATOMY

Detailed explanation-1: -Flat bones are thin and generally curved, with two parallel layers of compact bone sandwiching a layer of spongy bone. Most of the bones of the skull are flat bones, as is the sternum (breast bone).

Detailed explanation-2: -Flat bones are made up of a layer of spongy bone between two thin layers of compact bone.

Detailed explanation-3: -Compact bone forms a shell around cancellous bone and is the primary component of the long bones of the arm and leg and other bones, where its greater strength and rigidity are needed.

Detailed explanation-4: -Compact bone (or cortical bone) forms the hard external layer of all bones and surrounds the medullary cavity, or bone marrow. It provides protection and strength to bones. Compact bone tissue consists of units called osteons or Haversian systems.

Detailed explanation-5: -Spongy bone tissue does not contain osteons that constitute compact bone tissue. Instead, it consists of trabeculae, which are lamellae that are arranged as rods or plates. Red bone marrow is found between the trabuculae. Blood vessels within this tissue deliver nutrients to osteocytes and remove waste.