Human Anatomy

4. Blood vessels that carry blood back to the heart after it has delivered oxygen and nutrients to tissues.
6. The act of taking in oxygen and expelling carbon dioxide, an essential function of the respiratory system.
7. A large organ that processes nutrients from food, produces bile for digestion, and detoxifies chemicals in the blood.
9. Structures where two or more bones meet, allowing movement and flexibility in the skeletal system.
11. Chemical messengers produced by glands that regulate bodily functions like growth, metabolism, and mood.
13. The fluid that circulates through the body, transporting oxygen, nutrients, and waste. It’s essential for various bodily functions.
15. The smallest structural units of life, which make up all body tissues and organs.
17. A gas that the body needs to survive, essential for producing energy in cells through respiration.
18. Rigid organs that make up the skeletal system, providing structure, protection, and support to the body.
19. Bundles of fibers in the nervous system that transmit signals between the brain and other body parts, enabling sensation and movement.

1. A muscular organ that pumps blood throughout the body, supplying oxygen and nutrients to tissues and removing carbon dioxide and other wastes.
2. Tissues that allow movement by contracting and relaxing. They are part of the muscular system.
3. A hollow organ in the digestive system that breaks down food using digestive juices and enzymes.
5. Refers to the body’s defense system that protects against infections, diseases, and foreign invaders.
8. The process by which the body breaks down food into nutrients that can be absorbed and used for energy, growth, and repair.
10. The body's largest organ, which acts as a protective barrier, regulates temperature, and provides sensation.
12. The power derived from food and oxygen to fuel bodily functions, movement, and cellular processes.
13. The organ that controls thoughts, memory, emotions, and bodily functions. It is the central component of the nervous system.
14. Organs in the urinary system that filter blood, remove waste, and regulate fluid and electrolyte balance in the body.
16. Organs in the respiratory system responsible for taking in oxygen and releasing carbon dioxide through the process of breathing.