Do the vertebrae get larger as they go up or as they go down so as to support more and more weight?

Correct Answer: B

Rationale: Vertebrae increase in size from top (cervical) to bottom (lumbar) to support greater body weight and stress. Cervical vertebrae are smallest, thoracic intermediate, and lumbar largest, reflecting their load-bearing roles.

Correct Answer: A

Rationale: The ulna is slightly longer than the radius and features the olecranon (elbow projection) and coronoid process (anterior projection), forming the elbow joint with the humerus. The radius lacks these.

Correct Answer: A

Rationale: The tibia, the larger leg bone, bears most of the body’s weight and has a fibular notch distally to articulate with the fibula, stabilizing the ankle.

Correct Answer: D

Rationale: The sternum (breastbone) is part of the axial skeleton, forming the thoracic cage with the ribs to protect the heart and lungs. Scapula (shoulder blade), humerus (upper arm), and femur (thigh) are appendicular skeleton bones, involved in limb movement, not axial support.

Correct Answer: C

Rationale: The synovial membrane, lining synovial joint cavities, produces synovial fluid to lubricate and nourish the joint, reducing friction. Cartilage covers bone ends, ligaments connect bones, and periosteum covers bone surfaces—none produce this fluid.