Epithelial tissue

• Squamous epithelial tissue


  • Location: lines organs and surfaces.
  • Function: it's one cell thick, forms a thin, smooth, flat layers which are ideal for rapid diffusion of oxygen.
  • It can be damaged by smoking, it will irritate and cause scarring in the epithelium tissue of the lungs. The alveoli walls become thicker due to scaring and produce more mucus which wont let it function effectively causing the lungs to lose oxygen.
• Ciliated columnar epithelial tissue


  • Location: line the trachea with column-shaped ciliated cells which are hair like structures.
  • Function: protect the lungs from infection by sweeping away pathogens and secreting mucus to trap pathogens.
  • They secrete mucus to help trap unwanted particles that are present in the air we breath. Protects the lungs by not letting bacteria reach the alveoli.
• Endothelial tissue


  • Location: lining of the heart, blood vessels, lymphatic vessels.
  • Function: provide short diffusion pathways for the movement of products of digestion into blood capillaries.
  • Arteriosclerosis develops when carbon monoxide and high blood pressure damage the inner lining of the arteries or cause a build up of fat which limits blood flow and limits the flow of oxygen in the body.