Histology of the Respiratory System Flashcards
What structure makes up most of the volume of the lungs?
Alveoli
The mucosa of the conducting portion of the respiratory tract is responsible for…
Warming, humidifying, and filtering the air (it is well-vascularized, wet, and sticky)
What kind of cells make up the respiratory epithelium?
Pseudostratified, columnar, and ciliated and Goblet cells
What are small granule cells?
- Part of the diffuse neuroendocrine system
- Secrete products across their basal surface into intersitial fluid
- Coordinate the function of adjacent cells and tissues
What are basal cells in the respiratory endothelium?
Mitotically active stem cells
Where is the olfactory epithelium located and what other cells does it contain?
- Roof of nasal cavity and superior conchae
- Has chemosensitive olfactory neurons
- Support cells
- Basal cells
True or False:
Olfactory neurons are capable of regeneration.
Yes; they regenerate every 2-3 months
What are the three layers of the trachea?
Mucosa, submucosa, and adventitia
C-shaped cartilage rings in the trachea are located between…
The submucosa and adventitia
C-shaped cartilage rings in the trachea are located between…
The submucosa and adventitia
What is the trachealis?
A smooth muscle that connects the two ends of the cartilage rings posteriorly, to allow the esophagus to bulge as we swallow, and to contract during coughing
The cartilage rings are attached to the submucosa and adventitia via…
Pericardium
The cartilage rings are attached to the submucosa and adventitia via…
Pericardium
What are the submucous glands?
Produce watery mucus in the submucosa of the trachea
What is the progression of the bronchial tree?
Trachea –> primary bronchi –> secondary bronchi –> terminal bronchi –> smaller bronchi –> bronchioles –> terminal bronchioles –> alveoli
What are bronchopulmonary segments?
Independent subunits of lung tissue surrounded by a CT capsule, each with their own air, nerve, blood, and lymphatic vessel supply
What is the structure of bronchi?
- Complete cartilaginous rings
- Abundant seromucous glands
- As bronchi branch, cartilage begins to decrease and smooth muscle increases
What is the structure of bronchioles?
- Lack cartilage and seromucous glands
- Have a continuous layer of smooth muscle
- The epithelium becomes cuboidal ciliated cells
- Cilia eventually disappear
What are bronchiolar exocrine cells?
- Secrete surfactant
- Helps maintain alveolar patency
- Contains antimicrobial peptides and cytokines
What are respiratory bronchioles?
- Structurally similar to terminal bronchioles
- Surrounded by alveoli
- Open into alveolar ducts
Interalveolar septae consist of….
- CT with elastic and reticular fibres, which provides structure and elasticity to alveoli
What are pneumocytes?
- Line alveoli
- Squamous epithelial cells
- Type I and type II
Type I vs type II pneumocytes
- Type I: cover 95% of SA, but only make up 40% of the epithelium
- Type II: produce surfactant, only cover 5% of SA
Adjacent alveoli are connected by…
Interalveolar pores, the allow for collateral air flow between alveoli
