Gas exchange in the lungs occurs where?
What is the common structure found in these locations?
Respiratory bronchioles, alveolar ducts, alveolar sacs
All contain alveoli
The conducting passages of the respiratory system are lined by what?
What is the purpose of the respiratory mucosa?
Provide immunological and physical barrier
Source secretory products necessary for respiratory function
Serve as a selective absorptive interface
What are the three mucosal structures present in all parts of the lung conducting passages?
Describe the histological features of the nasal mucosa
Epithelium: pseudostratified columnar epithelia with goblet cells
Lamina Propria: prominent venous plexus and seromucous glands
The interactions between mucosal cilia and glands that removes foreign particles from the respiratory passages is called what?
The mucociliary escalator
Give (5) cell types found in the respiratory epithelium
Small Granule cells
Name (4) cell types found in the olfactory epithelium?
Name one unique histological feature of the nasopharynx mucosa
The true vocal cord is lined by what type of epithelium?
stratified squamous epithelium
stress/abrasion from turbulent airflow
The trachea contains a deep layer (below the lamina propria) with prominent seromucous glands. Name it.
Prominent c-shaped cartilage rings is characteristic of what level of the repiratory conducting pathways?
What is the primary mechanical support of the bronchi?
What is a clara cell? What is (likely) their main function?
A multifunctional cell type that replaces goblet cells in the terminal bronchioles.
Secrete protective glycosaminoglycans to protect the bronchiole lining
Describe the metaplastic effect of smoking on the respiratory epithelium
Smoking causes continuous irritation of the pseudostratified columnar respiratory epithelia. This induces a metaplastic transformation to pseudostratified squamous epithelia.
Define: pulmonary lobule
A terminal bronchiole and the lung tissue it supplies
Define: pulmonary acinus
Portion of the lung supplied by a respiratory bronchiole
What cell type makes up most of the surface area of the alveoli?
Which cell type is most numerous?
Which cell type secretes surfactent?
Type I pneumocytes
Type II pneumocytes
Type II pneumocytes
Give the general components of surfactent
- Phospholipid - phosphotidylcholine, phosphotidylglycerol
- Proteins - surfactent proteins A, B, C, D
Where is ACE found?
ACE is found on the pulmonary capillar endotheliual cells
The alveolar walls are supported by what structural proteins?
collagen fibrils and elastin
Name the (4) components of the blood-air barrier of the alveolar system
- Type I pneumocyte cell body (thin portion)
- Fused basement membrane of Type I pneumocytes and capillary endothelium
- capillary endothelial cell
- Erythrocyte plasma membrane
What are alveolar dust cells?
If these cells take up excessive amounts of hemosiderin, what are they now called?
heart failure cells