| A | B |
|---|
| alveoli | small sacs inside the lungs where oxygen and carbon dioxide are exchanged and moved into the blood |
| arteries | Blood vessels that carry blood away from the heart |
| vein | A blood vessel that carries blood back to the heart. |
| blood vessels | Tube like structures that carry blood throughout the body |
| capillaries | Smallest blood vessels where gas exchange and the movement of nutrients and wastes in and out of cells occurs |
| Neuron | a nerve cell; the basic building block of the nervous system |
| villi | small finger-like structures in the inside wall of the small intestine that increase surface area so nutrients can be absorbed more quickly |
| tendon | Connects muscle to bone |
| ligament | Connects bone to bone |
| skin | largest organ of the body, maintains hydration, and stops infectious agents from entering |
| Lungs | two spongy organs, located in the thoracic cavity enclosed by the diaphragm and rib cage, responsible for respiration |
| Kidneys | Filter blood from the renal arteries and produce urine as waste |
| Homeostasis | A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level |
| Stimulus | a signal to which an organism responds; can be internal or external |
| stomach | large muscular sac that continues the mechanical and chemical digestion of food |
| brain | The mass of nerve tissue that is the main control center of the nervous system |
| heart | A hollow, muscular organ that pumps blood throughout the body. |
| spinal cord | Nerves that run up and down the length of the back and transmit most messages between the body and brain |
