Question

Chemical similar to surfactant, glycosaminoglycans of the lungs is released by ---- to protect bronchiole lining.

• A. Histiocytes of the lungs
• B. Kupffer cells of the liver
• C. Clara cells of the lungs
• D. None of the above

Answer 1

Answer: (C)

Clara cells of the lungs

The term "histiocytes" refers to specialized types of stationary macrophages, that remain in a particular body tissues rather than the bloodstream. They destroy foreign substances in an effort to protect the body from infections. Histiocytes are found in many organs and connective tissues, including alveoli of the lung, brain, breast tissue, epidermal tissues, liver, lymph nodes, placenta, serous cavities, spleen, tonsils.
"Kupffer cells" also known as stellate macrophages, are specialized macrophages located in the lining of the walls of the sinusoids of liver. They are a type of macrophage that capture and break down, old and worn out red blood cells passing through the sinusoid. They also response to infection and toxins by destroying bacteria and foreign protein.
"Club cells" also known as "bronchiolar exocrine cells" and originally known as "Clara cells", are dome-shaped cells with short microvilli. They are found in the ciliated simple epithelium in the bronchioles of the lungs. One of the main functions of club cells is to protect the bronchiolar epithelium. They do this by secreting a small variety of products, including club cell secretory protein "uteroglobin", and "glycosaminoglycans" similar to the component of the lung surfactant. They are also responsible for detoxifying harmful substances inhaled into the lungs. Club cells also act as a stem cell, multiplying and differentiating into ciliated cells to regenerate the bronchiolar epithelium.