science vocab

Tissue

A group of similar cells that perform a specific function

Organ

Body structures that is composed of different kinds of structure

Homeostasis

The ability of an organism to maintain a normal internal state, in spite of changes in the external environment

Stimulus

Change or trigger

Gland

Organ that releases chemicals either through ducts or into blood stream

Hormone

Chemical messenger produce by an endocrine gland

Digestion

Process that breaks complex food molecules into nutrients

Nutrient

A substance such as a fat,protein or carbohydrate that a living thing needs to survive

Enzyme

Type of protein that speeds up chemical reactions in the body

Excretion

Process by which wastes are removed from body

Neuron

A cell that carries information through the nervous system

Reflex

Automatic response that occurs rapidly