Tissues

Examples of Tissues in the following topics:

• Complex Tissue Structure

  • Animals, besides Parazoa (sponges), are characterized by specialized tissues such as muscle, nerve, connective, and epithelial tissues.
  • In addition, animals possess unique tissues, absent in fungi and plants, which allow coordination (nerve tissue) and motility (muscle tissue).
  • In vertebrates, bone tissue is a type of connective tissue that supports the entire body structure.
  • Epithelial tissues cover, line, protect, and secrete; these tissues include the epidermis of the integument: the lining of the digestive tract and trachea.
  • For example, the evolution of nerve tissues and muscle tissues has resulted in animals' unique ability to rapidly sense and respond to changes in their environment.

• Types of Connective Tissue

  • Connective tissues encompass a diverse array of tissue types that are involved in binding and supporting body structure and tissues.
  • These tissues are widely distributed and serve as a universal packing material between other tissues.
  • The functions of areolar connective tissue include the support and binding of other tissues.
  • The two types of adipose tissue are white adipose tissue (WAT) and brown adipose tissue (BAT).
  • Bone tissue is also called the osseous tissue.

• Tissues

• Plant Tissues and Organ Systems

• Characteristics of Connective Tissue

  • Connective tissue (CT) is a one of the four main classes of tissues.
  • Although it is the most abundant and widely distributed of the primary tissues, the amount of connective tissue in a particular organ varies.
  • Connective tissue fibers provide support.
  • Three types of fibers are found in connective tissue:
  • They help the connective tissue to stretch and recoil.

• Connective Tissues: Loose, Fibrous, and Cartilage

  • Connective tissue is found throughout the body, providing support and shock absorption for tissues and bones.
  • The matrix in connective tissues gives the tissue its density.
  • Collagen fibers provide strength to the tissue, preventing it from being torn or separated from the surrounding tissues.
  • Loose connective tissue, also called areolar connective tissue, has a sampling of all of the components of a connective tissue.
  • Cartilage is a connective tissue.

• Characteristics of Epithelial Tissue

  • The human body consists of four types of tissue: epithelial, connective, muscular, and nervous.
  • Epithelial tissue covers the body, lines all cavities, and composes the glands.
  • In its role as an interface tissue, epithelium accomplishes many functions, including:
  • Protection for the underlying tissues from radiation, desiccation, toxins, and physical trauma.
  • Regulation and excretion of chemicals between the underlying tissues and the body cavity.

• Tissues in Levels of Organization

  • Tissues are groups of similar cells that have a common function.
  • The four basic tissue types are epithelial, muscle, connective, and nervous tissue.
  • Each tissue type has a characteristic role in the body:
  • Most organs contain more than one tissue type.
  • Cells form tissues, and tissues form organs.

• Lymphoid Tissue

  • The tissues of lymphoid organs are different than the tissues in most other organ systems because different tissues within the system vary considerably based on cell cycle proliferation of lymphocytes.
  • Secondary lymphoid tissue provides the environment for the antigens to interact with the lymphocytes.
  • Lymphatic tissues begin to develop by the end of the fifth week of embryonic development.
  • Development of lymphatic tissue starts when venous endothelial tissues differentiate into the lymphatic endothelial tissues.
  • The thymus and bone marrow are primary lymphoid tissue, while the lymph nodes, tonsils, and spleen are secondary lymphoid tissue.

• Plant Tissues and Organ Systems

  • Plant tissue systems fall into one of two general types: meristematic tissue and permanent (or non-meristematic) tissue.
  • Dermal tissue covers and protects the plant.
  • Dermal tissue, for example, is a simple tissue that covers the outer surface of the plant and controls gas exchange.
  • Vascular tissue is an example of a complex tissue.
  • The vascular bundles are encased in ground tissue and surrounded by dermal tissue.