22 CLASSIFICATION OF TISSUES. 
It is almost entirely wanting in extensibility, and is therefore non- 
elastic. 
Wit structures are composed almost entirely of white fibrous 
issue ? 
Tendons, ligaments, periosteum of bone, fascia, and all tissve in 
which great strength is needed without extensibility. 
Of what is white fibrous tissue composed ? 
Of bundles of white fibres which in turn are made up of finer fibres 
or fibrilla. The fibres and fibrille: are held together by an intercellu- 
lar cement substance These fibres usually run parallel, and although 
they may interlace they never branch. Here and there between the 
fibres are found flattened connective tissue cells, called tendon cells. 
Describe the physical characteristics of yellow elastic tissue. 
As its name indicates it is yellow in color and is very elastic, readily 
contracting after having been extended. It is not so strong as the 
white fibrous tissue, breaking when over-extended. 
Where is this tissue found in the human body most abundantly ? 
In the ligamenta subjlava, hyoid ligaments, vocal cords, and in 
the walls of the bloodvessels. 
What is the microscopic structure of yellow elastic tissue ? 
It is composed of large, clear fibres which branch, giving a sort of 
reticulated appearance when partly separated. 
one ne differential points between white fibres and yellow elastic 
res. 
White fibres are made up of finer fibrillee which usually run parallel; 
they may interlace, but they never branch. Yellow elastic jibres are 
coarse, highly refractive, they do branch, and when torn apart have a 
tendenoy to curl up at the ends. 
What are the macroscopical appearances of areolar tissue ? 
It is soft and fleecy-looking, but having considerable strength and 
elasticity, and when stretched between the fingers it seems to be com- 
posed of a multitude of clear-shining fibres intermixed with fine films, 
or lamelle. 
Where is areolar tissue found in the body ? 
It is the most widely distributed tissue. Starting under the skin 
where it is abundant it may be traced under serous and mucous 
membranes, along bloodvessels, and nerves, around and between 
