A tissue is a collection of identical or different differentiated cells including their extracellular matrix ( intercellular ). The cells of a tissue have similar or the same functions and perform together as a rule, the functions of the tissue.
Basically, leave all of a multicellular organism, that is, all the organs, structures and other contents of animals and plants, assign a tissue, or they have been produced by one tissue type.
With the structure of tissues, the histology is concerned, with pathological changes in the histopathology.
Animal tissue types
In all vertebrates, and nearly all invertebrates, with the exception of tissue lots such as the sponges, there are four basic tissue types can be distinguished:
- Epithelial tissues: cell layers that cover all the inner and outer surfaces. It is roughly divided into surface and glandular epithelia.
- Connective and supporting tissue: tissue that provides structural integrity and spaces filled (this includes bone, cartilage and adipose tissue ) and in the broadest sense more specialized tissues (blood, free cells ) produces.
- Muscle tissue: cells that are specialized by contractile filaments for active movement.
- Nervous tissue: cells that make brain, spinal cord and peripheral nerves are built.
Some authors reckon tissue fluid, or liquid fabric as the blood and lymph within the basic tissue types, others as special Gewebsform. Organs are often made with the actual functional tissue ( parenchyma ) and the interstitial tissue ( interstitium ).
Plant tissues types
- Education tissue ( meristems ) from proliferating embryonic cells
- Permanent tissue are tissue in plants that are no longer capable of division.
One divides the permanent tissue into:
- Parenchyma ( ground tissue ): It stores water, starch, fats and proteins. An example of this is the cortex ( bark not ).
- Dermal tissue: The final tissue is used to protect the plant. It is the outer skin of the plant, including epidermis, exodermis and cork.
- The Supporting Tissues ensures the maintenance of the plant. There are living and dead tissue consolidation. The living, usually woody Supporting Tissues called collenchyma and the dead, mostly lignified sclerenchyma.
- Vascular tissue responsible for the transport in the plant. The phloem transports the products of photosynthesis and the xylem is responsible for the water and Nährsalztransport.
- Excretion tissue is distinguished in excretion and Sekretionsgewebe
As the founder of histology to Marie François Xavier Bichat, who discovered a variety of tissue types in the human body.
Assaying of fixed and stained tissue sections under the light microscope is the classic method of histology. Electron microscopy, fluorescence microscopy, freeze-fracture techniques and molecular biological advances have influenced and advanced the knowledge about the structure and function of the tissue significantly.