Across
- 4. A long, cylindrical, contractile cell that forms muscles.
- 5. A flexible tissue connecting bones at joints.
- 7. The body's main artery.
- 8. The process by which cells release energy from glucose.
- 9. The powerhouse of the cell.
- 12. The tiny sacs in the lungs where gas exchange occurs.
Down
- 1. The fluid-filled sac surrounding the heart.
- 2. The pigment responsible for skin, hair, and eye colour.
- 3. The body's largest organ.
- 6. The brain's outermost layer.
- 10. The system responsible for gas exchange in the body.
- 11. The smallest unit of an element.