Types of Tissues

4.1 Types of Tissues

• Learning Outcomes:

  • Understand where tissues relate in the biological levels of organization.

  • Describe the four major classes of tissues and provide a general function for each.

Biological Levels of Organization

• Cells are composed of molecules.

• Tissues are a group of similar cells.

• Organs contain several different types of tissues.

• Multiple organs are found in an organ system.

Tissues

• A tissue is composed of specialized cells of the same type that perform a common function in the body.

• The tissues of the human body can be categorized into four major types:

  • Connective tissue: Binds and supports body parts.

  • Muscular tissue: Moves the body and its parts.

  • Nervous tissue: Receives sensory information and conducts nerve impulses.

  • Epithelial tissue: Covers body surfaces and lines body cavities.

Biology in Your Life: How are Cancers Named?

• Cancers are classified according to the type of tissue from which they arise.

  • Sarcomas: Cancers arising in muscular or connective tissue, especially bone or cartilage.

  • Leukemias: Cancers of the blood.

  • Lymphomas: Cancers of lymphoid tissue.

  • Carcinomas: Cancers of epithelial tissue (the most common type).

• The chance of developing cancer in a particular tissue is related to the rate of cell division.

  • Epithelial cells and blood cells reproduce at a higher rate.

  • Thus, carcinomas and leukemias are common types of cancer.