Lesson 6 Body Membrane.pdf

BODY MEMBRANE Body membranes cover surfaces, line body cavities and form protective (and often lubricating) sheets around organs. TWO MAJOR GROUPS: a. epithelial membranes – includes cutaneous, mucous, and serous membranes b. connective tissue membrane – synovial...

BODY MEMBRANE Body membranes cover surfaces, line body cavities and form protective (and often lubricating) sheets around organs. TWO MAJOR GROUPS: a. epithelial membranes – includes cutaneous, mucous, and serous membranes b. connective tissue membrane – synovial membrane EPITHELIAL MEMBRANE o covering and lining membrane o contain epithelial sheet and underlying connective tissue Body Tissue makeup Functions membrane Cutaneous  your skin  Protection membrane  Superficial epidermis is composed of  Sensing a keratinizing stratified squamous  regulation epithelium  The underlying dermis is mostly dense (fibrous) connective tissue  Exposed to air and dry membrane Mucous  composed of epithelium (the type  Lines all body cavities that Membrane varies with the site) resmting on a open to the exterior, such (mucosa) loose connective tissue membrane as those of the hollow called a lamina propria. organs of the respiratory,  The term mucosa refers only to the digestive, urinary, and location of the epithelial membranes, reproductive tracts not the cellular makeup  The epithelium of mucosae  Most mucosae contain either is often adapted for stratified squamous epithelium (as in absorption or secretion the mouth and esophagus) or simple  Not all secretes mucus (for columnar epithelium (as in the rest of example, urinary tract) the digestive tract).  they are “wet,” or moist, membranes that are almost continuously bathed in secretions or urine in the case of the urinary mucosae. Serous  composed of a layer of simple  line body cavities that are membrane squamous epithelium resting on a closed to the exterior thin layer of areolar connective (except for the dorsal body tissue. cavity and joint cavities).  To understand the relationship  The serous fluid allows the between serous membranes and an organs to slide easily organ, imagine your fist as an organ. across the cavity walls and Now imagine pushing your fist into one another without an inflated balloon, which represents friction as they carry out the cavity membranes. The part of their routine functions. the balloon in contact with your fist This is extremely (the inner balloon wall) represents important when mobile the visceral (vis′er-ăl; organ) serous organs such as the membrane, and the outer part of the pumping heart and a balloon wall represents the parietal churning stomach are (pă-rī′ĕ-tăl; wall) serous membrane. involved. The cavity, or space, between the visceral and parietal serous  membranes is normally filled with a thin, lubricating film of serous fluid produced by the membranes. As an organ rubs against another organ or against the body wall, the serous fluid and smooth serous membranes reduce friction.  Serous membranes also compartmentalize the various organs to prevent infection in one organ from spreading to others.  The specific names of the serous membranes depend on their locations.  The serosa lining the abdominal cavity and covering its organs is the peritoneum.  In the thorax, serous membranes isolate the lungs and heart from one another. The membrane surrounding the lungs is the pleura;  that around the heart is the pericardium. Synovial  composed of soft areolar connective  line the fibrous capsules membrane tissue surrounding joints  contains no epithelial cells  where they provide a smooth surface and secrete a lubricating fluid.  also line small sacs of connective tissue called bursae and the tubelike tendon sheaths. o The serous membranes can become inflamed—usually as a result of an infection. o Pericarditis is inflammation of the pericardium. o Pleurisy is inflammation of the pleura o Peritonitis is inflammation of the peritoneum. One form of peritonitis occurs when the appendix ruptures as a result of appendicitis. o Appendicitis is an inflammation of the appendix that is usually caused by a bacterial infection.