Squamous Epithelial Cells: Organelles, Structure, and Function

Squamous epithelial cells (flattened, scale-like) line surfaces requiring rapid diffusion/filtration (alveoli, endothelium, serous membranes). Organelles:

• Cell membrane: Phospholipid bilayer with proteins; selective permeability.
• Cytoplasm: Cytosol + organelles; thin in squamous cells.
• Nucleus: Flattened; contains DNA, directs transcription.
• Mitochondria: ATP production; fewer due to low metabolic demand.
• Ribosomes: Protein synthesis (free and ER-bound).
• Endoplasmic Reticulum: Smooth (lipid synthesis, detox) and rough (secretory proteins).
• Golgi Apparatus: Modifies, sorts, packages proteins/lipids.
• Lysosomes: Degradation (less prominent in thin squamous cells).
• Centrioles: Microtubule organizing center for division.

Specializations: tight junctions (barrier), caveolae (transcytosis in endothelium), Weibel-Palade bodies (von Willebrand factor storage).