| A | B |
| red marrow | the spongy material in bones that makes blood cells |
| platelet | a blood cell that helps blood clot |
| tendon | a tough strip of tissue that connects a muscle to a bone |
| involuntary muscle | a muscle that a person cannot control |
| voluntary muscle | a muscle that a person can control |
| enzyme | a protein that speeds up chemical changes |
| esophagus | the tube that connects the mouth to the stomach |
| peristalsis | the movement of digestive organs that pushes food through the digestive tract |
| villi | structures in the small intestine through which food molecules enter the bloodstream |
| artery | a blood vessel that carries blood away from the heart |
| blood pressure | the push of blood against the walls of blood vessels |
| capillary | a blood vessel that exchanges gases, nutrients, and wastes with body cells |
| vein | a blood vessel that carries blood to the heart |
| antibody | a protein in plasma that fights disease |
| hemoglobin | a substance in red blood cells that carries oxygen |
| plasma | the liquid part of blood |
| ligament | a tissue that connects bone to bone |