Fig. 2.
Fig. 2. Represents a portion of broken muscular fibre of animal life, (magnified about seven hundred diameters.)
27. The term SYSTEM is applied to an assemblage of organs arranged according to some plan, or method; as the nervous system, the respiratory system.
22. Define a fibre. 23. Define a fasciculus. 24. Define a tissue. 25. Define an organ. What is the action of an organ called? Give examples. Mention other examples. 26. What is an apparatus? Give an example 27. How is the term system applied?
28. A TISSUE is a simple form of organized animal substance. It is flexible, and formed of fibres interwoven in various ways; as, the cellular tissue.
29. However various all organs may appear in their structure and composition, it is now supposed that they can be reduced to a few tissues; as, the Cel´lu-lar, Os´se-ous, Mus´cu-lar, Mu´cous, Ner´vous, &c. ([Appendix B.])
30. The CELLULAR TISSUE,[2] now called the areolar tissue, consists of small fibres, or bands, interlaced in every direction, so as to form a net-work, with numerous interstices that communicate freely with each other. These interstices are filled, during life, with a fluid resembling the serum of blood. The use of the areolar tissue is to connect together organs and parts of organs, and to envelop, fix, and protect the vessels and nerves of organs.