| A | B |
|---|
| cell | basic unit of life |
| tissue | group of similar cells working together to perform a function |
| oxygen | waste gas produced by plants during photosynthesis; used by plants and animals during cellular respiration |
| carbon dioxide | waste gas produced by cellular respiration; used by plants to make food during photosynthesis |
| blood | red liquid that circulates in the arteries and veins of humans and other vertebrate animals, carrying oxygen to and carbon dioxide from the tissues of the body |
| pulse | rhythmical throbbing of the arteries as blood is propelled through them, typically as felt in the wrists or neck |
| heart | muscular organ that pumps blood |
| blood vessel | a tubular structure carrying blood through the tissues and organs; a vein, artery, or capillary |
| artery | blood vessel that carries blood away from the heart to the body |
| vein | blood vessel that carries blood from the body to the heart |
| capillary | smallest blood vessel |
| right atrium | upper chamber on the right side of the heart |
| left atrium | upper chamber on the left side of the heart |
| right ventricle | lower chamber on the right side of the heart |
| left ventricle | lower chamber on the left side of the heart |
| circulatory system | system of blood vessels and organs that transports blood to all the cells in the body |
| respiratory system | system of lungs and connecting tubes that transports oxygen to the red blood cells and gets rid of carbon dioxide |
| lung | organ in animals where gases such as oxygen and carbon dioxide pass between the atmosphere and the blood |
| cellular respiration | process by which energy for life is released from food in cells |
