3.1 tissues and organs

• a tissue is a group of cells with similar structure and function
• animal tissues include muscular tissue, glandular tissue and epithelial tissue
• muscular tissue are tissues that contract to bring about movement.
• glandular tissues are tissues that produce substances such as enzymes or hormones.
• epithelial tissues are tissues which cover some parts of the body.
• Organs are made of tissues.
• multicellular organisms are made up of organ systems that work together.
• examples of organ systems include:

  • the digestive system
  • the circulatory system
  • the gas exchange system