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Body Systems Vocab
Science Vocabulary
| Term | Definition |
|---|---|
| cell differentiation | the process by which cells become different types of cells. |
| tissue | a group of similar types of cells that work together to carry out specific tasks. |
| organ | a group of different tissues working together to perform a particular job. |
| organ system | a group of organs that work together and perform a specific task. |
| muscle | strong body tissue that can contract in an orderly way. |
| joint | where two or more bones meet. |
| ligament | the tissue that connects bones to other bones. |
| hydrostatic skeleton | a fluid-filled internal cavity surrounded by muscle tissue. |
| exoskeleton | a thick, hard outer covering; protects and supports an animal’s body. |
| cardiac muscle | muscle found only in the heart. |
| smooth muscle | involuntary muscle named for its smooth appearance. |
| Calorie | the amount of energy it takes to raise the temperature of 1 kg of water by 1°C. |
| nutrient | a part of food used by the body to grow and survive. |
| digestion | the mechanical and chemical breakdown of food into small particles and molecules that your body can absorb and use. |
| mechanical digestion | a process in which food is physically broken into smaller pieces. |
| chemical digestion | a process in which chemical reactions break down pieces of food into small molecules. |
| esophagus | a muscular tube that connects the mouth to the stomach. |
| peristalsis | waves of muscle contractions that move food through the digestive tract. |
| villus | fingerlike projections, many of which cover the folds of the small intestine. |
| excretory system | the system that collects and eliminates wastes from the body and regulates the level of fluid in the body. |
| photosynthesis | a series of chemical reactions that convert light energy, water, and carbon dioxide into the food-energy molecule glucose and give off oxygen. |
| vascular tissue | specialized plant tissue composed of tubelike cells that transports water and nutrients in some plants. |
| xylem | a type of vascular tissue that carries water and dissolved nutrients from the roots to the stem and the leaves. |
| phloem | a type of vascular tissue that carries dissolved sugars throughout a plant. |
| stoma | a small opening in the epidermis, or surface layer, of a leaf. |
| pharynx | a tubelike passageway at the top of the throat that receives air, food, and liquids from the mouth or nose. |
| trachea | a tube that is held open by C-shaped rings of cartilage; connects the larynx and the bronchi. |
| bronchi | two narrow tubes that carry air into the lungs from the trachea. |
| lungs | the main organs of the respiratory system. |
| diaphragm | a large muscle below the lungs that contracts and relaxes as air moves into and out of your lungs. |
| alveoli | microscopic sacs or pouches at the end of the bronchioles where gas exchange occurs. |
| atria | the upper two chambers of the heart. |
| ventricles | the lower two chambers of the heart. |
| artery | a vessel that carries blood away from the heart. |
| vein | a vessel that carries blood toward the heart. |
| capillary | a tiny blood vessel that delivers supplies to an individual cell and takes away waste materials. |
| open circulatory system | a system that transports blood and other fluids into open spaces that surround organs in the body. |
| closed circulatory system | a system that transports materials through blood using vessels. |
| nervous system | the part of an organism that gathers, processes, and responds to information. |
| neuron | the basic functioning unit of the nervous system; a nerve cell. |
| central nervous system | system made up of the brain and the spinal cord. |
| spinal cord | a tubelike structure of neurons that sends signals to and from the brain. |
| peripheral nervous system | system made of sensory and motor neurons that transmit information between the central nervous system (CNS) and the rest of the body. |
| sensory system | the part of your nervous system that detects or senses the environment. |
| receptor | special structures in all parts of the sensory system that detect stimuli. |