| A | B |
|---|
| molting | a process of shedding an outgrown exoskeleton |
| cartilage | a connective tissue that is more flexible than bone |
| joint | a p;ace in the body where two bones come together |
| muscle | a tissue that contracts or relaxes to make movement |
| nervous system | an organ system that receives information from the environment and coordinates a response |
| stimulus | any change or signal in the environment that can make an organism react in someway |
| response | an action or change in behavior that occurs as a result of a stimulus |
| neuron | a cell that carries information through the nervous system |
| impulse | an electrical message that carries information in the nervouse system |
| sensory neuron | a neuron that picks up stimuli from the internal or external environment and converts each stimulus to a nerve impulse |
| interneuron | a neuron that carries nerve impulses from one neuron to another |
| motor neuron | a neuron that sends an impulse to a muscle or gland, causing the muscle or gland to react |
| brain | an organized grouping of neurons in the head of an animal with bilateral symmetry |
| water vascular system | a system of fluid filled tubes in an echinoderm's body |
| swim bladder | an internal gas filled organ that helps a bony fish stabilize its body at different water depths |
