Human Systems

4. takes up oxygen from the air we breathe.
6. muscle that is common in the walls of hollow organs and blood vessels.
9. made up of glands that make hormones.
17. your body's outer layer.
18. made up of blood vessels that carry blood away from and towards the heart.
19. chemicals that affect growth a d development.
20. protects your body from harmful substances, and germs.
21. gives your body its shape, allows movement, makes blood cells.

1. chromosomes move in opposite directions so two new cells can be formed from one.
2. chromosomes move from the center toward the opposite ends of a dividing cell.
3. The process by which a single parent cell divides to make two new daughter cells.
5. strong, flexible connective tissue that protects your joints and bones.
7. the organ in your chest that pumps the blood around your body.
8. a system that removes excess and waste products from the body to maintain homeostasis.
10. where your body breaks down food and absorbs nutrients.
11. One of a pair of bones at the base of the front of the neck.
12. includes the brain, spinal cord, and a complex network of nerves.
13. a network of hormone production that work together to create life.
14. type of cell division during which a single cell divides twice and produces four daughter cells.
15. composed of specialized cells called muscle fibers.
16. made of connective tissue reinforced with calcium.