Respiratory - histology Flashcards
Describe respiratory epithelium
Pseudostratified columnar epithelium ciliated with goblet cells
Function of the nasal cavity
to produce space for warming, moistening, and filtering inspired air
Where is specialised olfactory epithelium found
Roof of the nasal cavity
What lines the vestibule of the nasal cavity
keratinised stratified squamous epithelium
What is underneath the respiratory epithelium of the nasal cavity (3)
Lamina propria
Loose connective tissue band containing seromucous glands
Thin-walled venous sinuses
What do the walls of the larynx consist of (3)
cartilage
Muscle
Respiratory epithelium
What is the trachea composed of (2)
C-shaped cartilages
With gap spanned by fibro-elastic tissue and smooth muscle
What is beyond the respiratory epithelium of the trachea (3)
basal lamina
Lamina propria
Submucosa
How are the bronchi different histologically from the trachea
the cartilages are irregular rather than C shaped
What do the walls of the bronchi consist of (3)
respiratory epithelium
Lamina propria
Muscularis
Describe the Muscularis of bronchi walls (4)
Ring of smooth muscle with
Adipose tissue
Submucosa
Seromucous glands
Bronchiole histology (3)
epithelium goes from columnar to cuboidal
May contain goblet cells
Lack cartilage
What is the lamina propria of bronchioles composed of (3)
smooth muscle
Elastic fibres
Collagenous fibres
What are terminal bronchioles (2)
The smallest bronchioles
Lack respiratory function
How do bronchioles respond to parasympathetic inner action
Smooth muscle contraction leads to Constriction of bronchiole
What unique type of cell do terminal bronchioles contain
non-ciliated club cells
Which project above layer of ciliated cells
Going from bronchioles to alveoli, what change happens
cuboidal epithelium is replaced by discontinuous squamous type I alveolar cells
What are the types of epithelial cells of alveoli (2)
type I alveolar cells - simple squamous epithelium
Type II alveolar cells - polygonal cells
Function of type II alveolar cells (3)
Reducing tendency for alveoli to collapse after expiration
release surfactant via exocytosis
This surfactant spreads over pulmonary surface to reduce surface tension at air-fluid interface
Where is surfactant found in type II alveolar cells
cytoplasm, in membrane-bound lamellar bodies
Which type of alveolar cell is more abundant
type I
What other type of cell (not epithelial) do alveoli contain
alveolar macrophages
Describe action of alveolar macrophages (3)
phagocytose inhaled particles
Transported by ciliary action to pharynx
Are swallowed/move into septal connective tissue
What are lung surrounded by (and what is this made of 2)
visceral pleura
(Mesoepithelium backed by fibrous and elastic connective tissue)
What structures are alveoli associated with (3)
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
describe the conducting portion of the airway (2)
Extends form trachea to terminal bronchioles
No gas exchange occurs with blood
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