Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 10

Silicosis and Asbestosis. Silicosis is a debilitating miner's disease that results from the ingestion of silica particles (such as sand or glass)by macrophages in the lungs. Asbestosis is a similarly serious disease caused by inhalation of asbestos fibers. In both cases, the particles or fibers are found in lysosomes, and fibroblasts, which secrete collagen, are stimulated to deposit nodules of collagen fibers in the lungs, leading to reduced lung capacity, impaired breathing, and eventually death.
(a)How do you think the fibers get into the lysosomes
(b)What effect do you think fiber or particle accumulation has on the lysosomes
(c)How might you explain the death of silica-containing or asbestos-containing cells
(d)What do you think happens to the silica particles or asbestos fibers when such cells die How can cell death continue almost indefinitely, even after prevention of further exposure to silica dust or asbestos fibers
(e)Cultured fibroblast cells will secrete collagen and produce connective tissue fibers after the addition of material from a culture of lung macrophages that have been exposed to silica particles. What does this tell you about the deposition of collagen nodules in the lungs of silicosis patients