NORMAL HISTOLOGY. 



CHAPTER VIII. 



CONNECTIVE TISSUE. 



Connective tissue is derived from the mesoblast and consists of 

 cells and intercellular substance. It is found between the skin and 

 mucous membranes. It differs chiefly from epithelial tissue in 

 having a greater amount of intercellular substance. Its functions 

 are to connect different structures and furnish support to the or- 

 gans of the body. The cells entering into it are of two kinds, fixed 

 and wandering. The fixed cell is a flattened plate with nucleus, 

 protoplasm, and enclosing membrane. Sometimes there are projec- 

 tions of the cell-wall which give a stellate appearance. Wandering 

 cells (such as leucocytes) are those which migrate from place to 

 place in the tissue. 



There are ten important kinds of connective tissues viz., white 

 fibrous tissue, yellow elastic tissue, areolar tissue, adipose tissue, 

 mucous tissue, retiform tissue, basement membranes, cartilage, bone, 

 and dentine. 



I. WHITE FIBROUS TISSUE. 



This form is composed of delicate fibrils, often collected into bun- 

 dles. The bundles may run parallel with each other or interlace, 

 forming a mesh-work. This tissue is found in tendons, the omen- 

 turn, subcutaneous tissues, etc. In a tendon the fibrils compose 

 parallel primary bundles, and these unite to form secondary bun- 

 dles, each of which is enveloped in a delicate sheath. All are bound 

 together to form the tendon, which is encased in a tough sheath of 

 connective tissue, septa from which extend inward, enclosing the 

 secondary bundles. 



laboratory exercise No. 17. Tendon. Embed a piece of tendon in 

 celloidin. Stain sections with carmine, method No. 2. Make out the ex- 

 ternal sheath and the septa of connective tissue. Observe the branched 

 spaces for tendon cells. Demonstrate, if possible, the primary bundles 

 and the ends of the fibrils. Label and preserve. Drawing's. 



II. YELLOW ELASTIC TISSUE. 



This consists of highly refracting fibres which form a network 

 and are often associated with the preceding tissue. The fibres, when 



