Give observation 2d. 31. What is said of the identity of this tissue? 32. Name the varieties of tissue formed from the cellular. 33. Where is the serous tissue found? What two offices does it perform? Give its structure. What is the use of this membrane?
34. The DERMOID TISSUE covers the outside of the body. 21 It is called the cu´tis, (skin.) This membrane is continuous with the mucous at the various orifices of the body, and in these situations, from the similarity of their structure, it is difficult to distinguish between them.
Observations. 1st. In consequence of the continuity and similarity of structure, there is close sympathy between the mucous and dermoid membranes. If the functions of the skin are disturbed, as by a chill, it will frequently cause a catarrh, (cold,) or diarrhœa. Again, in consequence of this intimate sympathy, these complaints can be relieved by exciting a free action in the vessels of the skin.
2d. It is no uncommon occurrence that diseased or irritated conditions of the mucous membrane of the stomach or intestines produce diseases or irritations of the skin, as is seen in the rashes attendant on dyspepsia, and eating certain species of fish. These eruptions of the skin can be relieved by removing the diseased condition of the stomach.
35. The FIBROUS TISSUE consists of longitudinal, parallel fibres, which are closely united. These fibres, in some situations, form a thin, dense, strong membrane, like that which lines the internal surface of the skull, or invests the external surface of the bones. In other instances, they form strong, inelastic bands, called lig´a-ments, which bind one bone to another. This tissue also forms ten´dons, (white cords,) by which the muscles are attached to the bones.
Observation. In the disease called rheumatism, the fibrous tissue is the part principally affected; hence the joints, where this tissue is most abundant, suffer most from this affection.
34. Describe the dermoid tissue. What is said of the sympathy between the functions of the skin and mucous membrane? Give another instance of the sympathy between these membranes. 35. Of what does the fibrous tissue consist? How do these appear in some situations? How in others? What tissue is generally affected in rheumatism?
36. The ADIPOSE TISSUE is so arranged as to form distinct bags, or cells. These contain a substance called fat. This 22 tissue is principally found beneath the skin, abdominal muscles, and around the heart and kidneys; while none is found in the brain, eye, ear, nose, and several other organs.
Observation. In those individuals who are corpulent, there is in many instances, a great deposit of this substance. This tissue accumulates more readily than others when a person becomes gross, and is earliest removed when the system emaciates, in acute or chronic diseases. Some of the masses become, in some instances, enlarged. These enlargements are called adipose, or fatty tumors.