Respiratory Division Histology Flashcards
What distinguishes respiratory bronchioles from terminal bronchioles?
Walls are interrupted by occasional alveoli
What are the components to the respiratory division?
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli
What controls the opening of the alveoli?
A single smooth muscle cell (form a knob)
What is the thinnest area of the alveoli?
Alveolar septum
What makes up the alveolar septum?
Type I and II alveolar cells Continuous capillaries Basal lamina Type III collagen Elastic fibers macrophages, fibroblasts, mast cells Lymphoid elements
~95% of the alveolar wall is covered by what cell?
Type I pneumocyte
Are there more type I pneumocytes or type II pneumocytes?
Type II pneumocytes
What is surfactant contained in in the type II pneumocytes?
Lamellar bodies
What is the role of the alveolar macrophages?
phagocytose particulate matter
What type of capillaries are found in the lung?
Continuous capillaries
Where do pulmonary artery branches run?
Parallel to bronchial tree
Where do pulmonary veins drain?
Azygous system
Where does the superficial lymph system drain?
Hilar lymph nodes
Where do the deep network of lymph vessels follow?
Follow pulmonary arteries, veins, and bronchial tree
Where does the sympathetic nerve supply to the lungs come from?
Thoracic sympathetic chain ganglia
