4. Joints and ligaments (a) are found in the brain. (b) make red blood cells. (c) let bones move.

Joints and ligaments are fascinating structures that play a crucial role in our musculoskeletal system. Joints are the connections between bones that allow us to move freely, while ligaments are strong bands of tissue that hold bones together, providing stability during movement. Whether you're bending your elbow or flexing your knees, these structures work together to ensure fluid and safe motion! In real-world applications, understanding joints and ligaments is vital for fields like sports medicine and physical therapy. Injuries such as torn ligaments or joint sprains can sideline athletes, highlighting the importance of warm-ups and proper techniques during physical activities. Knowledge of these body parts helps professionals design effective rehabilitation programs and prevent injuries, keeping people active and healthy!