Emergency Medical Technician (EMT) Intermediate Practice Exam

The mouth, nose, and other body orifices are lined with what kind of membranes?

1. Serous membranes

2. Connective membranes

3. Mucus membranes

4. Endothelial membranes

The correct answer is: Mucus membranes

The mouth, nose, and other body orifices are lined with mucus membranes, which play a vital role in protecting underlying tissues and keeping them moist. Mucus membranes are specialized epithelial tissues that secrete mucus, a thick, slippery fluid that acts as a barrier against pathogens, helping to trap dust and microbes, and facilitating the movement of materials within these areas. In contrast, serous membranes line body cavities that do not open to the outside, typically covering organs within those cavities. Connective membranes, which primarily consist of connective tissue, support and protect organs but don't provide the same barrier function as mucus membranes. Endothelial membranes are specialized for lining the interior surfaces of blood vessels and lymphatic vessels and do not pertain to external body openings. The specific function and location of mucus membranes make them the correct answer for the question regarding the lining of the mouth, nose, and other orifices.