7. Respiratory System Flashcards
What are the functions of the respiratory tract? (8)
- Filtration
- Humidification
- Warming
- Olfaction
- Gas transport
- Speech
- Protection against infection
- Gas exchange
Describe the respiratory epithelium.
Pseudostratified, ciliated, columnar epithelial cells interspersed with goblet cells
What are the 4 functions of the nose?
- Filtration
- Humidification
- Warming
- Olfaction
What is the epithelium of the nose?
- Keratinising and non-keratinising squamous epithelium
- Respiratory epithelium
- Richly vascular lamina propria containing seromucionous glands
Describe the olfaction epithelium on the roof of the nasal cavity.
- Pseudostratified epithelium of olfactory receptor cells with supporting sustentacular cells and basal cells
- Serous glands of Bowman
- Rickly innervated lamina propria
Describe olfactory receptor cells.
Bipolar neurones- dendrite extends to surface to become club-shaped ciliated olfactory vesicle
What are the 4 functions of the nasopharynx?
- Gas transport
- Humidification
- Warming
- Olfaction
What is the epithelium of the nasopharynx?
Respiratory epithelium
What are the 4 functions of the nasal sinuses?
- Lower the weight of the skull
- Add resonance to the voice
- Humidify air
- Warm air
What is the epithelium of the nasal sinuses?
Respiratory epithelium
What is the function of the larynx?
Voice production
Describe the epithelium of the larynx.
- Respiratory epithelium
- Loose fibrocollagenous stroma with seromucinous glands
- Lymphatics and blood vessels common
What is the epithelium of the vocal cords?
Stratified swuamous epithelium overlying loose irregular fibrous tissue (Reinke’s space) with almost no lymphatics
What is the function of the trachea?
Conducts air to and from the lungs
Describe the trachea epithelium.
- Respiratory
- Seromucinous glands in submucosa
- Trachealis muscle posteriolry
- C-shaped cartilagenous rings
Describe the structures and epithelium of the main bronchi, lobar bronchi and bronchioles.
- Smooth muscle
- Partial cartilagenous rings
- Respiratory epithelium
- Some basal neuroendocrine cells
- Seromucinous glangs and goblet cells
Describe the structure and epithelium of bronchioles.
- Smooth muscle
- Ciliated columnar epithelium
- Some basal neuroendocrine cells
- Few goblet cells
- Clara cells
Describe clara cells.
- Most numerous in terminal bronchioles
- Mitochondria, sER
- Secretory granules
- No cilia, vesicular cytoplasm
Describe the epithelium of respiratory bronchioles.
- Cuboidal ciliated epithelium
- Spirally-arranged smooth muscle
- No cartilage
What is the function of respiratory bronchioles?
- Gas exhange as well as transport
- Link terminal brochioles and alveolar ducts
What are the 3 alveoli cell types?
- Type 1 pneumocytes
- Type 2 pneumocytes
- Alveolar macrophages
Describe type 1 pneumocytes.
- Flattened cells
- Flattened nucleus
- Few organelles
Describe type 2 pneumocytes.
- Rounded cells
- Round nucleus
- Rich in mitochondria
- sER and rER
- Spherical bodies
What is the most numerous alveolar cell type?
Type 2 pneumocytes
What cell type covers the largest surface area of the alveoli?
Type 1 pneumocytes
Describe alveolar macrophages.
- Luminal cells
- Also present in interstitium
What is the role of alveolar macrophages?
Phagocytose particulates including dusts and bacteria
What is the alveoli blood-air barrier?
Fused basement membrane of type 1 pneumocyte and capillary vascular endothelial cell
Describe the epithelium of the visceral pleura.
- Flat mesothelial cells
- Loose fibrocollagenous connective tissue
- Irregular external elastic layer
- Interstitial fibrocollagenous layer
- Irregular internal elastic layer
What does alveolar interstitium contain?
- Blood vessels
- Lymphatics
- Collagen
- Elastin
- Some macrophages
