Biological tissue

Biological tissue is a substance made up of cellsthat perform a similar function.

The study of tissues is known as histology, or, in connection with disease, histopathology.

The classical tools for studying the tissues are the wax block, the tissue stain, and the optical microscope, though developments in electron microscopy, immunofluorescence, and frozen sections have all added to the sum of knowledge in the last couple of decades.

With these tools, the classical appearances of the tissues can be examined in health and disease, enabling considerable refinement of clinical diagnosis and prognosis.

Animal Tissues

There are four basic types of tissue in the body of all animals, including the human body and lower multicellularorganisms such as insects. These compose all the organs, structures and other contents.

• Epithelium - Tissues composed of layers of cells that cover organ surfaces such as surface of the skin and inner lining of digestive tract. The tissues serve for protection, secretion, and absorption.
• Connective tissue - As the name suggests, connective tissue holds everything together. Bloodis considered a connective tissue.
• Muscle tissue - Muscle cells contain contractile filaments that move past each other and change the size of the cell. Muscle tissue also is separated into three distinct categories: visceral or smooth muscle, which is found in the inner linings of organs; skeletal muscle, which is found attached to bone in order for mobility to take place; and cardiac muscle which is found in the heart.
• Nervous tissue - Cells forming the brain, spinal cordand peripheral nervous system.

Plant Tissues

Examples of tissue in other multicellularorganisms are vasculartissue in plants, such as xylemand phloem. Plant tissues are categorized broadly into three tissue systems: the epidermis, the ground tissue, and the vascular tissue.

• Epidermis - Cells forming the outer surface of the leavesand of the young plant body.
• Vascular tissue - The primary components of vascular tissue are the xylemand phloem. These two tissues transport fluid and nutrients internally.
• Ground tissue - Ground tissue is less differentiatedthan other tissues. Ground tissue manufactures nutrients by photosynthesisand stores reserve nutrients.

See also

• Cellular differentiation

References

• Raven, Peter H., Evert, Ray F., & Eichhorn, Susan E. (1986). Biology of Plants (4th ed.). New York: Worth Publishers. ISBN 0-87901-315-X.

cs:Pletivo da:Væv de:Gewebe (Biologie) et:Kude es:Tejido biológico eo:Histo fr:Tissu biologique is:Vefur it:Tessuto (biologia) he:???? ???? ku:Tevînek lt:Audinys mk:????? ms:Tisu biologi nl:Weefsel (biologie) ja:?? (???) pl:Tkanka pt:Tecido (histologia) simple:Tissue (biological) sr:????? sv:Vävnad ta:???? vi:Mô tr:Doku (biyoloji) wa:Texhou zh:?? (???)

This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/Biological+tissue Wikipedia article Biological tissue.