Lecture 21 - Pulmonary Histology Flashcards
What are the components of the respiratory mucosa?
L21 S6
Pseudostratified ciliated columnar epithelium
Lamina propria:
-thin layer of loose connective tissue
Submucosa:
-dense irregular connective tissue
What are the histological characteristics of the nose?
L21 S7
Nares:
- stratified squamous epithelium
- contains sebaceous glands, sudoriferous glands, and hair follicles
Mucosa:
-begins at nasal septum
What are the histological characteristics of the olfactory epithelium?
L21 S9
Located in nasal cavity roof
- pseudostratified columnar without goblet cells
- no basement membrane
- sustentacular (support) cells
- basal cells (stem cells which give rise to olfactory cells
Olfactory cells:
- bipolar neurons
- cilia containing G-protein linked odor receptors
Olfactory cells of Bowman:
-secrete odorants-binding proteins
What are the histological feature of the nasopharynx?
L21 S12
Mucosa:
- respiratory epithelium
- lamina propria with FECT, mucous glands, serous/mixed glands, and lymphoid tissue
Submucosa:
- loose CT
- MALT (lymphoid associated lymphoid tissue
Waldeyer’s ring:
-lymphoid tissue ring around nasopharynx (adenoids and tonsils)
What are the histological fracture of the larynx?
L21 S13-15
Epiglottis:
- stratified squamous epithelium (lingual surface)
- pesudostratified ciliated epithelium (pharyngeal surface)
False vocal cords:
-pseudostratified ciliated epithelium with seromucous glands
True vocal cords:
-stratified squamous epithelium without seromucous glands
Cartilaginous structures:
- hyaline (thyroid, cricoid, and areytenoid)
- elastic (corniculates, cuneiform, tips of arytenoids, epiglottis
What are the histological features of the trachea?
L21 S16
Mucosa:
- respiratory epithelium, thick basement membrane
- lamina propria with FECT and lymphoid tissue
Submucosa:
-seromucous glands
Adventita:
- 16-20 cartilages connected by FECT
- mixed glands and capillaries
What are the histological features of the bronchi?
L21 S23
Mucosa:
- respiratory epithelium with thick basement membrane
- mucosal folds due to smooth muscle
- prominent elastic fibers
Submucosa:
- loose CT and lymphatic tissue
- mixed glands and mucous glands
Adventitia:
-hyaline cartilage plates with dense FECT
What are the histological characteristics of bronchioles?
L21 S25
- transition from ciliated columnar to ciliated cuboidal
- loss of cartilage
- loss of glands
- increase in smooth muscle
What are the histological characteristics of the respiratory bronchioles?
L21 S26
- low columnar to low cuboidal
- loss of cilia
- loss of goblet cells
- walls of smooth muscle and FECT
- some alveolar outpocketings
What are the histological features of alveolar ducts?
L21 S28
- squamous epithelium
- walls of smooth muscle and FECT
What are the histological characteristics of alveoli?
L21 S29
Type I alveolar cells (pneumocytes):
- cover large surface area
- less numerous
Type II alveolar cells (pneumocytes):
- cuboidal or rounded in shape
- serve as stem cells
Dust cells:
-macrophage
Pores of Kohn:
-openings between alveoli
What is the function of surfactant and where is it located?
L21 S34
- reduces surface tension of the alveolar surface
- contains dipalmitoyl phosphatidylcholine (lecithin)
- secreted by Clara cells and type II alveolar cells
What are Clara cells?
L21 S37
- found in bronchioles
- number increases further down the bronchioles
- bulging apical surface
- secretes lipoprotein
What are dust cells?
L21 S39
-macrophages which phagocytize pollutant, bacteria, and surfactant
In CHF broken down hemoglobin is phagocytized by dust cells which are then referred to as heart failure cells
What are the components of the blood-air barrier?
What is permitted to pass through?
L21 S41
Components:
- thin capillary endothelium
- thin epithelium of pneumocytes
- basal lamina of both cell types
Permits gas exchange only, no fluids or cells
