Respiratory System
What cells make up 5% of the alveolar surface?
granular alveolar type II cells
What happens when the pseudostratified ciliated columnar epithelium is injured?
hyperplasia or metaplasia (a change from pseudostratified ciliated columnar epithelium to stratified squamous epithelium)
What type of glands are contained in the lamina propria of the trachea?
serous glands
True or false: alveolar type I cells are extremely thin.
true
List 6 structures found in the alveolar septum.
1) fibroblasts 2) capillaries 3) dust cells 4) collagen type I 5) collagen type III 6) elastic fibers
What 5 "layers" make up the blood air barrier?
1) surfactant 2) pneumocyte type I 3) basal lamina of pneumocyte type I 4) basal lamina of endothelial cell 5) endothelial cell
What are the 3 regions of the nasal cavity and what is each lined by?
1) vestibular - keratinized stratified squamous epithelium 2) respiratory - pseudostratified ciliated columnar epithelium with goblet cells 3) olfactory - olfactory epithelium (much thincker and no goblet cells)
What does the lamina propria of the olfactory region of the nasal cavity contain?
Bowman's olfactory glands (serous glands) and the fila olfactoria
What is the fila olfactoria?
CN I - olfactory nerve
What completes the wall of the trachea?
CT adventitia
What is the visceral pleura lining the lungs composed of and lined by?
CT and simple squamous epithelium or mesothelial cells
What are the bronchioles of the transition zone lined by?
Clara cells, non-ciliated secretory cells, and a few ciliated cells
What are the purposes of alveolar pores?
allow passage of macrophages from one alveolus to another, equalization of pressure and collateral ventilation if a bronchiole is obstructed
What do alveolar ducts empty into?
alveolar sacs and alveoli
What are the walls of the alveolar ducts composed of?
alveoli lined by simple squamous epithelial cells
Which structures of the respiratory system are transitional?
bronchioles
What structures are lacking in the bronchioles?
cartilage and glands
What are the terminal bronchioles lined by?
ciliated cuboidal cells without goblet cells
What are respiratory bronchioles lined by?
ciliated cuboidal epithelium
What are the bone projections from the lateral wall of the nasal cavity called and what is their function?
conchae, or turbinates narrow the lumen of the nasal cavity and increase the area of contact of inhaled air with respiratory mucous membrane to regulate the quality and quantity of inhaled air
What do the pulmonary endothelium do?
convert angiotensin I to angiotensin II by releasing angiotensin converting enzyme, clear thrombi
What are the resident macrophages of the lungs?
dust cells
What are alveoli lined by?
epithelial type I and type II pneumonocytes
What type of junction holds pseudostratified ciliated columnar epithelium of the respiratory region of the nasal cavity together?
gap junctions
What type of cell is not found in healthy bronchioles?
goblet cells
What are the functions of Clara cells?
metabolize airborne toxins, immune function, produce surfactant
What do the mixed seromucous glands of the bronchi secrete?
mucin, lactoferrin, and lysozyme
What do goblet cells produce?
mucinogen granules
Which sturctures of the respiratory system are conductive?
nasal cavity, pharynx, larynx, trachea, and bronchi
Are the rings of cartilage in the trachea complete? What type of cartilage is this?
no except in birds, they are incomplete dorsally; hyaline
Do the trachea and esophagus have a serosa?
no!
Are alveolar type I cells permeable to fluid? gas? are they mitotic?
no; yes; no
What type of cells are found in the olfactory epithelium?
olfactory sensory cells
What is the vomeronasal organ used to detect?
pheromones
What are the bronchi lined by?
pseudostratified ciliated columnar epithelium
What is the trachea lined by?
pseudostratified ciliated columnar epithelium with goblet cells
What is the mucociliary apparatus and what is it responsible for?
pseudostratified ciliated columnar epithelium with goblet cells - clearance
What is the conducting system mostly lined by?
pseudostratified ciliated columnar epithelium with goblet cells and submucosal serous cells
What is the purpose of the surfactant produced by type II alveolar cells?
reduce surface tension
Which is the largest region of the nasal cavity?
respiratory
Which structures of the respiratory system are involved in gas exchange?
respiratory bronchioles and alveoli
What type of muscle is the trachealis muscle composed of?
smooth muscle
What type of tissue is found around the opening of each alveoli of an alveolar duct?
smooth muscle
What cells make up 95% of alveolar surface area?
squamous alveolar type I cells
What are basal cells and where are they found?
stem cells; olfactory epithelium
What is the larynx lined by?
stratified squamous epithelium which changes to pseudostratified ciliated columnar epithelium past the vocal folds
What do alveolar type II cells secrete?
surfactant made by lamellar bodies
What do Clara cells produce?
surfactant-like substance which aids in maintaining patency of airway
Where are Clara cells located?
terminal and respiratory bronchioles
What is a key characteristic in identifying Clara cells?
they bulge at the surface
What does the parietal pleura cover?
thoracic wall, diaphragm, and mediastinum
What does the lamina propria of the nasal cavity contain?
tubulo-alveolar glands, mainly serous, some mucous and mixed
What are the alveoli lined by?
type I and II pneumocytes
What are swell bodies?
venous plexuses engorged with blood in the olfactory and respiratory regions of the nasal cavity
Are alveolar type II cells mitotic?
yes!