22. What is the primary function of the periosteum? A. Cushioning joints B. Covering articular surfaces C. Nourishing bones D. Producing red blood cells E. Storing fat 23. The term "cranial"is synonymous with which directional term? A. Inferior B. Superior C. Anterior D. Posterior E. Lateral 24.Which bone type is characterized by its ability to reduce friction and protect tendons? A. Long Bones B. Short Bones C. Flat Bones D. Irregular Bones E. Sesamoid Bones 25. The thoracic cavity is separated from the abdominopelvic cavity by which structure? A. Peritoneum B. Pleura C. Diaphragm D Rib Cage E. Mediastinum 26. Which movement involves turning the palm of the hand downward? A. Supination B . Pronation C. Rotation D. Circumduction E Protraction 27. What is the primary function of osteoclasts in bone remodeling? A. Bone formation B. Bone resorption C. Calcium storage D . Hematopoiesis E Cartilage development

## Step 1<br />The primary function of the periosteum is to nourish the bone. It is a membrane that covers the outer surface of all bones, except for the joints of long bones. The periosteum consists of an outer fibrous layer and an inner osteogenic layer. The osteogenic layer contains osteoblasts and osteoclasts, which are involved in bone formation and resorption, respectively. Therefore, the correct answer is C. Nourishing bones.<br /><br />## Step 2<br />The term "cranial" refers to the skull or cranium, which is the part of the skeleton that encloses the brain. In anatomical terms, "cranial" is synonymous with "superior," which means toward the head or upper part of a structure. Therefore, the correct answer is B. Superior.<br /><br />## Step 3<br />Sesamoid bones are small, round bones that are embedded in tendons. They are typically found in locations where a tendon attaches to a bone, such as the patella (kneecap). Sesamoid bones help protect tendons from stress and wear and reduce friction. Therefore, the correct answer is E. Sesamoid Bones.<br /><br />## Step 4<br />The thoracic cavity is separated from the abdominopelvic cavity by the diaphragm. The diaphragm is a dome-shaped muscle that plays a crucial role in respiration. When it contracts, it flattens and moves downward, increasing the volume of the thoracic cavity and allowing air to be drawn into the lungs. Therefore, the correct answer is C. Diaphragm.<br /><br />## Step 5<br />Turning the palm of the hand downward is called pronation. In anatomical terms, pronation is the rotation of the hand and forearm so that the palm faces backward or downward. Therefore, the correct answer is B. Pronation.<br /><br />## Step 6<br />Osteoclasts are large cells that dissolve the bone. They are involved in the process of bone remodeling, which is the continuous cycle of bone formation and resorption. The primary function of osteoclasts is to break down and resorb bone tissue, making way for new bone to be formed. Therefore, the correct answer is B. Bone resorption.