YELLOW FIBROUS TISSUE. 



135 



The nuclear filaments are sometimes wound spirally around the fasciculi 

 or interlace with their separate fibres, at other times they are variously 

 twisted and run parallel with the fasciculi. The fasciculi are connected 

 and held together in the formation of membranes and cords by loose fibres 

 which are interwoven between them, or by mutual interlacement. 



Examples of white fibrous tissue are met with in three principal forms, 

 namely, membrane, ligament, and tendon. 



The membranous form of white fibrous tissue is seen in the common 

 connecting medium of the body, namely, fibro-cellular or areolar tissue, 

 in which the membrane is extremely thin and disposed in laminae, bands, 

 or threads, leaving interstices of various size between them. It is seen 

 also in the condensed covering of various organs, as the periosteum, peri- 

 chondrium, capsulse proprise of glands, membranes of the brain, sclerotic 

 coat of the eyeball, pericardium, fasciae ; sheaths of muscles, tendons, 

 vessels, nerves, and ducts ; sheaths of the erectile organs, and the corium 

 of the dermic and mucous membrane. 



Ligament is the name given to those bands of various breadth and thick- 

 ness which retain the articular ends of bones in contact in the construction 

 of joints. They are glistening and inelastic, and composed of fasciculi 

 of fibrous tissue ranged in a parallel direction side by side, or in some 

 situations interwoven with each other. The fasciculi are held together 

 by separate fibres, or by areolar tissue. 



Tendon is the collection of parallel fasciculi of fibrous tissue, by means 

 of which muscles are attached to bones. They are constructed on the 

 same principle with ligaments, are usually rounded in their figure, but in 

 some instances are spread out so as to assume a membranous form. In 

 the latter state they are called aponeuroses. 



Yellow fibrous tissue is known also by the appellation 

 elastic tissue, from one of its more prominent physical pro- 

 perties, a property which permits of its fibres being drawn 

 out to double their length, and again returning to their 

 original dimensions. The fibres of elastic tissue are trans- 

 parent, brittle, flat or polyhedral in shape, colourless when 

 single, but yellowish in an aggregated form, and considera- 

 bly thicker (50^0 of an mcn m diameter) than the fibres 

 of white fibrous tissue. In the construction of their pecu- 

 liar tissue they communicate with each other by means of 

 snort oblique fibres, which unite with adjoining fibres at 

 acute or obtuse angles, without any enlargement of the 

 fibre with which they are joined. This circumstance has 

 given rise to the idea of these fibres giving off branches, 

 an expression derived from the division of blood-vessels, 

 and another term borrowed from the same source has been 

 applied to their communication with each other, namely, 

 inosculation ; but both these expressions in their literal meaning are incor- 

 rect. When yellow fibrous tissue is cut or torn, the fibres in consequence 

 of their elasticity become clubbed and curved at the extremity, a striking 

 character of this tissue. 



* Yellovr fibrous tissue, shewing the curly and branched disposition of its fibrillca ; 

 their definite outline, and abrupt mode of fracture. At 1, the structure :,s not disturbed, 

 as in the rest of the specimen. Magnified 3:20 diameters. 



Fig. GO.* 



