Conducting Portion
- nasal cavity, paranasal sinus, nasopharynx, trachea
- primary, secondary, tertiary bronchi
- bronchioles, terminal bronchioles
Respiratory Portion
-respiratory bronchioles (not involved with gas exchange), alveolare ducts, alveolar sacs
Respiratory Epithelium
- Pseudostratified columnar ciliated epithelium with an extensive lamina propria
- “mucus membrane”
Cilia are never present on…
true stratified epithelium
Basal cells
- stems cells to repopulate epithelium/olfactory receptor
- not ciliated
Goblet cells
-synthesize and secrete mucus
Mucigen granules
- combine with water to make mucus
- secreted by goblet cells
Nasal vestibule
- just inside nose (outermost nasal cavity)
- lined by skin (keratinized stratified squamous)
Respiratory region
- inferior 2/3 of nasal cavity
- lined with respiratory mucosa
Olfactory region
- superior 1/3 of nasal cavity
- lined by olfactory mucosa
Turbinate bones
- increases surface area of the nasal cavity
- nasal cavity warms air
Olfactory Mucosa
- contains receptors for smell
- respiratory epithelium BUT lacks goblet cells* and is thicker* (**Hallmark: why it is given a different name)
Olfactory Glands
-serous secretions that dissolve odorant molecules
Olfactory Receptor Cells
- Have single dendritic process
- Specialized, nonmotile cilia w/ odorant receptors
- Ligand binding causes signals to be sent to olfactory bulb
Brush cells
-ciliated, columnar epithelial cells
Supporting/Sustentacular Cells
-provide support (mechanical/metabolic) to olfactory receptor cells
Trachea: 4 layers
- Mucosa (pseudostratified, ciliated + elastic/fiber rick LP)
- Submucosa (denser CT than LP)
- Cartilaginous (hyaline)
- Adventitia (Loose CT)
Bronchi hallmarks
Small cartilage plates
Bronchioles no longer have…
cartilage plates
Clara Cells
- secrete lipoprotein that prevents luminal adhesion with airway collapse (during expiration)
- found in terminal bronchioles
Alveolar Pores
small openings to allow air to move between alveoli
Alveolar Septum
-wall of alveolar capillaries that is surrounded by elastin and collagen fibers
Type I Pneumocytes
- simple squamous (why it takes up more space than II)
- create gas exchange surface (associated with caps)
Type II Pneumocytes
- rounded (more abundant than I)
- secrete surfactant to reduce surface tension to prevent collapse of alveoli
