Body Systems

4. system The body system that allows movement by contracting and relaxing muscles.
6. Organs in the respiratory system that allow oxygen to enter the blood and carbon dioxide to leave.
8. system The body system made up of bones that supports the body, protects organs, and allows movement.
9. A structure made of tissues that performs a specific function in the body.
12. system The system that produces and releases hormones to regulate body processes.
14. A muscular organ that pumps blood through the circulatory system.
16. The organ that controls thought, memory, emotions, and coordination of the body.
17. system The system that defends the body against germs, viruses, and other harmful invaders.
19. system The system that removes waste products and excess water from the blood as urine.
20. system The system that breaks down food into nutrients the body can use and absorbs them.

1. Chemical messengers produced by the endocrine system that regulate body activities.
2. The basic unit of life that makes up all living organisms.
3. A group of similar cells that work together to perform a specific function.
5. system The system responsible for producing offspring and hormones related to reproduction.
7. marrow Soft tissue inside bones that produces blood cells.
10. system The body system that transports blood, nutrients, gases, and wastes throughout the body.
11. system The system that brings oxygen into the body and removes carbon dioxide.
13. system A system of vessels and nodes that helps fight infection and maintain fluid balance.
15. An organ in the urinary system that filters blood to remove waste and produce urine.
18. system The system that controls body functions and responses by sending and receiving signals through nerves.