| A | B |
|---|
| tissue | A group of cells of the same type |
| organ | A group of tissues of different kinds working together to perform a task |
| cardiac muscle | A type of involuntary muscle that works the heart |
| smooth muscle | A type of involuntary muscle found in the walls of some organs such as the stomach, intestines, blood vessels, and bladder |
| striated muscle | A voluntary muscle with light and dark stripes |
| voluntary muscle | a muscle you control by thinking |
| involuntary muscle | A muscle that your body controls automatically without you thinking about it |
| lungs | The main organs of the respiratory system |
| capillary | A tiny blood vessel that allows gases and nutrients to pass from blood to cells |
| heart | The muscle that pumps blood through your blood vessels to all parts of your body |
| artery | A blood vessel that takes blood away from the heart |
| vein | A large blood vessel that returns blood to the heart |
| brain | The control center of your nervous system |
| neuron | A nerve cell |
| nerve | A group of neurons that carries signals from the brain to the body and from the body to the brain |
| spinal cord | The tube of nerves that runs through your spine, or backbone |
