Pulmonary Flashcards
What 5 cell types are present in CONDUCTING respiratory epithelium?
- Ciliated columnar
- Goblet
- Brush
- Small granule
- Basal
What type of epithelium is present in the CONDUCTING portion of the respiratory epithelium?
-Pseudostratified columnar epithelium
What is the most abundant cell in the CONDUCTING portion of respiratory epithelium?
-Ciliated columnar cells
What do Goblet cells do?
-Secrete mucin
What do Brush cells do?
- have microvilli
- chemoreceptors
What do small granule cells do?
- make peptide hormones that act as neurotransmitters
- sense O2 content of air?
What do Basal Cells Do?
-progenitor cells of the epithelium
What do ciliated columnar cells do?
-cilia beat to move mucus out of respiratory tract
What is squamous metaplasia?
- transformation of the pseudostratified epithelium into a non-keratinized stratified squamous epithelium
- can progress to pre-cancerous dysplasia
- caused by cigarette smoke
What can cause squamous metaplasia?
-smoking
What type of epithelium does RESPIRATORY epithelium have?
-simple columnar/cuboidal/squamous epithelium
What makes up the interalveolar septum?
- Fibroblasts
- Elastic & reticular fibers
- Macrophages
- immune cells
- Capillaries
- Alveolar (Kohn) pores
What is the purpose of the elastic and reticular fibers in the interalveolar septum?
- allows for controlled expansion of alveoli
- prevents collapse of alveoli
What is the purpose of alveolar pores?
- allow equalization of air pressure between alveoli
- collateral air circulation
- passage for macrophages
Compare/contrast Type I and II pneumocytes:
Compare:
-Desmosomes & occluding junctions
Contrast:
- Type I are thin, and make up most of the alveoli
- Type II are cuboidal, produce surfactant, cluster where 2+ alveoli unite, and have stem cell properties
What are the components of the respiratory membrane?
- Type I pneumocytes
- Thin capillary endothelial cell
- Fused basal laminae of Type I and cap endothelial cell
What produces pulmonary surfactant?
-Type II pneumocytes
What is the purpose of pulmonary surfactant?
- lower the surface tension at air epithelium interface
- prevents collapse at exhalation
What cells drink serfactant?
- Macrophages & both pneumocytes
- leads to high turnover
What is the cause of Infant Respiratory Distress Syndrom?
- Leading cause of death in premature babies
- The type II pneumocytes are not mature, thus there is no surfactant secretion
- alveoli collapse and cant epand sufficiently
- over time, hyaline membranes form
What are some treatments for Infant Respiratory Distress Syndrome?
- Glucocorticoid pre-nataly
- CPAP
- Endotracheal tube
- Exogenous surfactant
What do alveolar macrophages do?
- eat airborne particulate in the alveoli
- also drink surfactant
What are heart failure cells?
- alveolar macrophages which contain the iron pigment hemosiderin because they have been cleaning up RBC’s that have entered the alveoli
- caused by CHF and high blood pressure
What is present within the submucosa of the trachea?
- C-shaped rings of hyaline cartilage
- Trachealis muscle
What is present within the Lamina propria of the trachea?
- Lots of mucous glands
- serous mucous glands
What type of epithelium is present in the bronchi?
-pseudostratified ciliated columnar epithelium
What are the two stromal features of the bronchi?
- Lamina propria
- Submucosa
What is present within the Lamina propria of the bronchi?
- serous mucous glands
- smooth muscle & spiraled elastic fibers
- MALT lymphocytes
What is present within the submucosa of the bronchi?
-Isolated islands of hyaline cartilage
What are the two categories of lung cancer?
- Small cell carcinoma
- Non-small cell carcinoma
What type of epithelium is present in the regular bronchioles?
-pseudostratified ciliated epithelium transitioning to simple ciliated columnar epithelium
What are the two stromal features of the regular bronchioles?
-Lamina propria and submucosa
What is present within the lamina propria of regular bronchioles?
- no serous mucous glands
- circular layer of smooth muscle
What is present within the submucosa of regular bronchioles?
-no cartilage
What type of epithelium is present in the terminal bronchioles?
-simple ciliated cuboidal epithelium
What are the stromal features of the terminal bronchioles?
-a Lamina propria with elastic fibers and incomplete circular layer of smooth muscle
What cells are located within the epithelium of terminal bronchioles?
-Normal 5 PLUS Clara cells
What is the function of Clara cells?
- secrete surfactant
- detoxification
- secretion of antimicrobial peptides & cytokines
- Stem cells
What characterizes asthma?
- hypersecretion of mucous
- eosinophil infiltration
- bronchial smooth muscle hyperplasia
What type of epithelium is present in the respiratory bronchioles?
-simple cuboidal ciliated epithelium
What are the stromal features of the respiratory bronchioles?
-a lamina propria with smooth muscle and elastic tissue
What type of epithelium is present in the alveolar ducts?
-simple cuboidal and squamous epithelium
What are the stromal features of the alveolar ducts?
-a very thin lamina propria, with a strand of smooth muscle around alveolar openings, elastic and collagen fibers, and a network of capillaries
What type of epithelium is present in the alveoli?
-Simple columnar and cuboidal epithelium
What is emphysema? What causes it?
-a loosening of the elasticity of alveoli and respiratory bronchioles
caused by smoking and COPD
What is bronchitis? What causes it?
- lymphocyte infiltration causing enlargement of mucous secreting glands in the trachea and bronchus
- excessive mucous production causing coughing
What is pneumonia?
-Infection of the lung by either a virus, bacteria, or fungus
