Which membrane surrounds the heart and protects it within the chest cavity?

Which membrane surrounds the lungs and reduces friction during breathing movements?

Which protective membranes cover and protect the brain and spinal cord?

Which gas exchange membrane structure in the lungs maximizes surface area for efficient breathing?

Which fluid cushions and protects the brain and spinal cord from mechanical shock?

Which soft tissue found inside bones is responsible for producing new blood cells?

Which fluid lubricates joints and reduces friction between bones during movement?

Which flexible connective tissue cushions joints and is found in structures like the ear and nose?

Which fluid in the lymphatic system helps transport white blood cells and remove waste from tissues?

Which chamber of the heart pumps oxygenated blood out to the rest of the body?

Which white blood cell type is primarily responsible for producing antibodies against pathogens?