Textbook Objectives
1.) Function and location of the different membrane types:
a.) Cutaneous
b.) Mucosa
c.) Serosa
d.) Synovial
1.) a.) The cutaneous membrane is the skin. It is the dry, outermost protective boundary of the surface of the body. The cutaneous membrane consists of stratified squamos epithelium and the underlying connective tissues. The cutaneous membrane is thick, relatively waterproof, and dry. The main function of the cutaneous membrane is protection. Other functions include secretion, oil and sweat, waterproofing, keratin bacteriostatic acid mantle and sebum, and protection against damage(ex. scrapes, cuts, bruises, ect.). The cutaneous membrane is made up of keratinizing stratified squamous epithelium, and the underlying dermis is made up of mostly dense connective tissue.
b.) The mucosa membrane is the membrane that forms the linings of body cavities open to the exterior such as the digestive, respiratory, urinary, and reproductive tracts. The membrane functions are to protect, support, absorb nutrition, and to secrete mucus, enzymes, and salts. The mucosa membrane is made up of epithelium resting on a loose connective tissue membrane called the lamina propria.
c.) The serosa membrane is located within the abdominal cavity, around the lungs, and around the heart. The functions of the serosa membrane include secreting serous fluids, lining body cavities, and encllosing organs. The serous fluid allows the organs to slide easily across teh cavity walls and one another without friction as they carry out their routine fuctions. This is important when mobile organs such as the heart and stomach are involved. In the thorax serous membranes isolate the lungs and heart from one another. The serosa membrane is made up of a layer of simple squamous epithelium resting on a thin layer of areolar connective tissue.
d.) The synovial membrane lines the legament surfaces of joint capsules, tendon sheaths, areas where free movement is necessary, and the bursae. The function of the membrane is to provide a smooth surface and secrete a lubricating fluid. Synovial membranes also act as cusions to organs moving against each other. The synovial membrane is made up of connective tissues.
2.) List several important functions of the integumentary system and explain how each function is accomplished. (Table 4.1 from text).
Table 4.1
Functions Protects Deeper Tissues From: Mechanical Damage(bumps) Chemical Damage(acids and bases) Bacterial Damage Ultraviolet Radiation(damage) Thermal(heat or cold) Damage Desiccation(Drying Out) Aids in body heat loss or heat retention(controlled by the nervous system) Aids in excretion of urea and uric acid Synthesizes vitamin D |
Functions of the Integumentary System
How Accomplished: Physical barrier contains keratin, which toughens cells; fat cells to cushion blows; and pressure receptors, which alert the nervous system to possible damage. Has relatively impermable keratinized cells; contains pain receptors, which alert the nervous system to possible damage. Has an unbroken surface and "acid mantle" (skin secretions are acidic, and thus inhibit bacteria). Phagocytes ingest foreigh substances and pathogens, preventing them from penetrating into deeper body tissues. Melanin produced by melanocytes offers protection from UV damage. Contains heat/cold/pain receptors. Contains a waterproofing glycolipid and keratin. Heat loss: By activating sweat glands and by allowing blood to flush into skn capillary beds so that heat can radiate from the skin surface. Heat retention: By not allowing blood to flush into skin capillary beds. Contained in perspiration produced by sweat glands. Modified cholesterol molecules in skin converted to vitamin D by sunlight. |