c. Thermoregulation. Man is capable of maintaining a relatively constant body
temperature (37C or 98.6F). If man is in an environment of 100F, sensing devices in
the skin called receptors pick up the heat stimulus and send a message to the brain. A
temperature-regulating area of the brain sends nerve impulses to the sudoriferous
glands that cause these glands to produce more perspiration. As the perspiration
evaporates from the skin surface, the skin surface is cooled, and the body temperature
d. Types of Tissues. See figure 1-5.
(1) General. Tissue can be defined as a group of similar cells and their
intercellular substance functioning together to perform a specialized activity. Some
tissues move body parts. Other tissues move food through body organs while some
tissues protect and support the body. Other tissues produce chemicals such as
enzymes and hormones. Body tissues are classified by function and structure into four
principal types: epithelial tissue, connective tissue, muscular tissue, and nervous
tissue. Two of these types will be examined in this subcourse: epithelial tissue, which
covers body surfaces or tissues, lines body cavities, and forms glands; and connective
tissue, which protects and supports the body and its organs and binds organs together.
Figure 1-5. Types of skin tissues.