American Academy of Professional Coders (AAPC) Practice Exam

Which membrane is characterized by simple squamous epithelium?

1. Mucous Membrane

2. Serous Membrane

3. Synovial Membrane

4. Cutaneous Membrane

The correct answer is: Serous Membrane

The serous membrane is characterized by a simple squamous epithelium, which allows for efficient diffusion and secretion. This type of epithelium consists of a single layer of flat cells that provide a smooth surface, facilitating the movement of lubricating serous fluid. This fluid reduces friction between the organs and surrounding structures in body cavities, such as the pleural, peritoneal, and pericardial spaces. This is particularly important in organs that move or expand, as the smooth surface of the serous membrane prevents abrasion and inflammation. The structure of the serous membrane also helps with the absorption and transport of fluids and gases, key processes in maintaining homeostasis. Other membranes, like mucous membranes, synovial membranes, and cutaneous membranes, have different roles and cellular structures. Mucous membranes consist mainly of epithelium with goblet cells that produce mucus for lubrication and protection; synovial membranes are made of specialized connective tissue that also aids in lubrication but are not covered by a simple squamous epithelium; while cutaneous membranes, which are the skin, contain multiple layers of stratified epithelium, providing protection against environmental damage.