Respiratory System Flashcards
What is the air flow pathway?
Nasal cavity —> nasopharynx —> larynx —> trachea —> bronchi —> bronchioles —> terminal bronchioles —> respiratory bronchioles —> alveolar ducts —> alveolar sacs
Which division of the nervous system results in bronchoconstriction? Dilation?
Constriction: parasympathetic
Dilation: sympathetic
What are the two pleural layers? Which one adheres to the thoracic wall?
Visceral envelops the lungs, parietal adheres to thoracic wall.
What type of epithelium is “respiratory epithelium?” Which portion of the airways is covered in respiratory epithelium (conducting vs. respiratory)? Does gas exchange occur?
Pseudostratified ciliated columnar. Covers the conducting portion only. No gas exchange.
Name five cells found in respiratory epithelium.
- Ciliated columnar cells
- Goblet
- Brush cells
- Neuroendocrine (Kulchitsky’s) cells
- Basal reserve cells
What do brush cells do?
Microvilli - might do fluid absorption or chemoreception.
What do basal reserve cells do?
They differentiate into other cell types. Ahhhh! Call in the reserves, man!
What do neuroendocrine (Kulchitsky’s) cells do? Do they stain with H&E?
Contain peptide hormones and catecholamines and are part of the diffuse neuroendocrine system. Not visible with H&E.
Name the three layers of the respiratory epithelium.
- Lamina lucida
- Lamina densa
- Lamina reticularis
What is the lamina reticularis made of? What happens to it in asthma?
Fine fibrillary collagen. It thickens in asthmatics.
What is the most distal component of the conducting portion?
Bronchioles.
What are vibrissae?
Nose hairs.
Where are olfactory mucosa located?
Superior concha, roof/upper third of the nasal septum.
What cells are found in the olfactory mucosa?
Sustenacular (supporting) cells, olfactory nerve cells, and basal cells.
What neuronal type are the olfactory cells?
Bipolar
Where are Bowman’s glands found? What do they do?
Found in the submucosa of nasal cavity. They secrete a fluid over the epithelium in which odorates dissolve, then they bind to olfactory cells.
What two structures are in the larynx?
Epiglottis, vocal apparatus.
What epithelial types are found on the epiglottis?
SSNKE on superior surface, respiratory epithelium on inferior surface.
What two things are found in the lamina propria of the larynx?
Seromucous glands and elastic cartilage plate.
What type of epithelium are found on the false vocal cords and true vocal cords?
False - respiratory epithelium
True - stratified squamous
Describe the composition of the true vocal cords.
Stratified squamous epithelium, with large elastic fiber bundle, the vocal ligament, and a parallel skeletal muscle bundle called the vocalis muscle.
What type of cartilage is found in the larynx?
Mostly hyaline, some elastic.
Describe the histologic layers of the trachea.
Mucosa, submucosa, adventitia.
What is unique about the adventitia of the trachea?
Has c-shaped cartilage with a trachealis muscle that connects the ends of the C together.
Which primary bronchi is wider, shorter, and more vertical?
The right one.
What separates bronchopulmonary segments? Do these share blood supplies and conducting airways?
CT septa. Do not share blood supply nor conducting airways.
What do intrapulmonary bronchi arise from?
Divisions of the primary bronchi = intrapulmonary bronchi.
Desecribe the mucosa of the intrapulmonary bronchi.
Respiratory epi, lamina propria, muscularis mucosae.
What do the submucosal glands of the intrapulmonary bronchi do?
Secrete bronchial fluid.
Do bronchioles have cartilage and submucosal glands?
Nope
Describe the epithelium of the bronchioles.
Trick question!
Larger bronchioles have respiratory epi
Smaller ones have simple cuboidal ciliated with ciliated goblet cells and club cells.
What are club cells?
Clara cells be clubbin, dome-shaped, non-ciliated protenitor cells that are involved in detoxifying inhaled chemicals.
Are elastic fibers found in the CT of the adventitia of bronchioles?
For sho.
What type of epithelium is found in the terminal bronchioles?
Simple cuboidal ciliated with club cells.
Describe the lamina propria and muscularis mucosae of the terminal bronchioles.
Lamina propria has collagen and elastic fibers, muscularis mucosae is incomplete.
Are respiratory bronchioles distal to terminal bronchioles?
Yeah. Terminal bronchioles are not terminal!
What is a pulmunary lobule? What do they contain?
Terminal bronchiole + everything distal to it. Contain several respiratory lobules, alveolar ducts, sacs, and alveoli.
What separates pulmonary lobules from each other?
CT septa.
What is an acinus (terminal respiratory unit)?
Functional unit of the lung, includes everything distal to a respiratory bronchiole.
What type of epithelium is found in the respiratory bronchioles?
Cuboidal with goblet cells and club cells.
What separates alveoli?
Septa
What is a pore of Kuhn? What do they do?
They are holes in the septa that separate alveoli. They equalize pressure but also are susceptible to spreading infections.
What two cells types are found in alveoli?
Type 1 and Type 2 pneumocytes.
Which alveolar cell is predominant? What do these cells do?
Type 1 is predominant (97%) - they are flattened simple squamous cells, form the blood-air barrier.
What do Type 2 pneumocytes do?
Produce surfactant. They also have mitotic capability.
What are multilamellar bodies (aka cytosomes)?
They are what surfactant is packaged into.
How are multilamellar bodies released by Type 2 pneumocytes?
Exocytosis.
Name the layers of the blood-air barrier.
- Surfactant
- Cytoplasm of thin Type 1 pneumocyte
- Fused basal lamina between Type 1 cell and capillary endothelial cell
- Endothelial cell cytoplasm
What is the histologic relationship between bronchioles and pulmonary arteries?
They follow each other and share adventitia!
What are nutritive (bronchial) arteries?
They supply O2 rich blood to lung tissue and follow the bronchial tree.
What are the three components of the pulmonary defense system?
Secretions, clearance, cellular.
Which cells participate in secretory defense in the lungs? What does the secretion contain?
Goblet cells, seromucous glands, club cells. Secretion contains secretory IgA and interferon.
Which cells participate in cellular-component pulmonary defense?
Alveolar macrophages, other macrophages in the interstitial tissue, plasma cells, BALT (bronchus-associated lymphoid tissue), and club cells.
How do club cells participate in cellular-component pulmonary defense?
They are involved in deactivation of xenobiotics and inhaled chemicals.
Do Bowman’s glands secrete mucus or serous product?
Serous
Do pulmonary veins follow the bronchial tree?
No, why would they? They just need to get the blood back to the heart!
Where are seromucous glands found in the respiratory system?
Trachea and intrapulmonary bronchus.
What do sympathomimetic drugs do?
Stimulate bronchidilation - used to treat asthma
Where do submucosal glands and cartilage stop?
At large bronchioles.
