Respiratory System: Slides
#5 Trachea
In this cross section of the trachea note the C-shaped ring of hyaline cartilage and the pseudostratified ciliated columnar epithelium. Cilia are clearly seen in some areas but goblet cells may not be obvious. Exocrine glands are found beneath the epithelium. Lymph nodes and diffuse, sub-epithelial lymphatic tissue are seen. Note also the nerves, blood vessels and adipose tissue. This is a good slide to review these structures.
#88 Trachea and Esophagus
Look for the same structures in this slide and the following slide. What criteria do you use to distinguish between the esophagus and the trachea?
#89 Lung, (H&E)
Identify an intrapulmonary bronchus by irregularly shaped cartilage plates in its wall. Bronchioles, terminal bronchioles, respiratory bronchioles, and alveoli should be identified. Alveolar ducts, and alveolar sacs may also be seen. Compare the epithelial linings of each of these portions of the respiratory tree. Also compare the lining of the respiratory tract to the endothelium of blood vessels.
#118 Lung, (H&E)
This lung slide is useful for examining larger portions of the respiratory tree and the vascular system. The alveoli are somewhat collapsed. Look for an area in which the alveolar walls are intact. Note the close contact of the smallest capillaries (one red blood cell in diameter) and the simple squamous epithelium lining the alveolus. Gas exchange between blood and air occurs here. Although it is difficult to distinguish type I pneumocytes from endothelial cells, you can identify type II pneumocytes and macrophages. Macrophages are frequently found along the wall of the alveolus, or free within the alveolar space. Type II pneumocytes are present in the epithelium lining the alveolus.
Be sure you know the types of cells found in the alveolus and how they can be distinguished structurally. Know the function of each cell type. Use TEMs to identify cell types and to aid in understanding the structure of the alveolar wall.
#110 Lung, Elastin Stain - Paraffin section 6μm
This stain highlights the elastic fibers (red brown) in the lung.
