The body’s ability to maintain a stable internal environment
Homeostasis
The jellylike fluid inside a cell where many cell activities occur
Cytoplasm
A protein that speeds up chemical reactions in the body
Enzyme
The system responsible for taking in oxygen and removing carbon dioxide
Respiratory System
A nerve cell that sends and receives electrical and chemical signals
Neuron
All chemical reactions that occur in the body to keep you alive
Metabolism
The control center of the cell containing DNA
Nucleus
The body system made of bones that supports and protects the body
Skeletal System
The organs that break down food into nutrients the body can use
Digestive System
A chemical messenger produced by glands that regulates body processes
Hormone
A group of similar cells that work together to perform a specific function
Tissue
Organelles that produce energy for the cell; known as the “powerhouses.”
Mitochondria
The system made of muscles that allows movement of the body
Muscular System
The system of glands that releases hormones to regulate body functions
Endocrine System
A blood vessel that carries blood away from the heart
Artery
A group of organs that work together to carry out major body functions
Organ System
The movement of molecules from an area of high concentration to low concentration
Diffusion
The system that receives information, processes it, and sends signals to control body activities
Nervous System
The system that helps defend the body against infection and returns fluid to the bloodstream
Lymphatic System
A blood vessel that carries blood back to the heart
Vein
The protective outer boundary of a cell that controls what enters and leaves
Cell Membrane
The diffusion of water across a selectively permeable membrane
Osmosis
The heart and blood vessels that transport blood and nutrients throughout the body
Cardiovascular System
The skin, hair, and nails that protect the body from the environment
Integumentary System
The smallest blood vessels where gas and nutrient exchange occurs
Capillary