Module 7 Pulmonary Flashcards
Review: Explain TLC,RV,FVC,FEV and FEF
TLC: total lung capacity (lung volume following max inhalation)
RV: residual volume (volume following max exhalation)
FVC: forced vital capacity (volume exhaled with force following max inhalation)
FEV: forced expiratory volume (volume exhaled with force over a given period of time 1sec=FEV1)
FEF 25%-75%: forced expiratory flow (measure of airflow midway through exhalation)
Airway histology review: In bronchi what cells are present?
Epithelium: Ciliated columnar cells, goblet cells, basal cells (multipotent progenitor) and neuroendocrine cells (Chemoreceptors in hypoxia detection) Basement membrane Smooth Muscle Seromucinous glands Cartilage Vasculature and lymphatics
Airway histology review: In bronchioles what cells are present?
Epithelium: ciliated columnar cells and clara cells BM Smooth muscle vasculature and lymphatics no cartilage or glands
Review: differentiate between type I and type II pneumocytes
type I: flat and can not replace itself; 95% of volume of alveoli are these cells
type II: larger, cuboidal, produce surfactant; can differentiate — replaces injured epithelial (type I); located away from wall/gas diffusion
What structures are in the conduction, transition and respiratory zones?
Conduction zones: Bronchi and Bronchioles
Transition Zone: Respiratory Bronchioles
Respiratory zone: Alveoli ducts and Alveoli
What is atelectasis?
Alveolar collapse = loss of lung volume = decreased oxygenation —- ventilation perfusion imbalance — massive intrapulmonary shunting but normal blood flow
–caused by inadequate expansion of airspaces
There are three types of atelectasis each card will go through one. First is resorption (obstructive)
Resorption: obstruction of the bronchial lumen and this is reversible
- -obstruction by either a FB (right main stem b/c its straight) , mucus plug or centrally located tumors
- –xray: trachea goes to the same side as the obstruction
What are the different pathologies that cause mucus plugs that end up obstructing the lumen of the bronchus?
Chronic Bronchitis
CF
Kartagener Syndrome
Status Asthmatic
What are the different pathologies that cause centrally located tumors?
Squamous cell lung cancer, small cell carcinoma and Bronchial carcinoma
The second type of atelectasis is compression, what are the characteristics of this
Reversible and involves air or fluid in the pleural cavity:
- -pneumothorax, hemothorax, penumohemothorax, chylothorax (lymph), empyema (pus) and pleural effusion
- –xray: trachea is pushed to the opposite side (Not in the lab slides it shows a right sided pneumothorax so trachea goes to the left)
The third type of atelectasis is contraction, what are the characteristics of this?
Anything that causes pulmonary fibrosis and is therefore irreversible
- -trachea is usually midline
- –FEV:FVC ratio is normal but decreased TLC:RV
The next category of atelectasis is dealing with premature babies, what type of atelectasis is this?
Get microatelectasis because of lack of surfactant ( micro lung collapse) because very immature type 2 pneumocytes
In surfactant it is composed of lipoproteins, phosphatidylcholin (lecithin), Phosphatidylglycerol and proteins. What are the specific proteins and their associated functions
Surface proteins (SP) A and D: innate immunity Surfactant proteins (SP) B and C: reduction of surface tension at air liquid barrier in alveoli
Surfactant is synthesized in type 2 pneumocytes, at how many weeks gestation does the surfactant start getting synthesized?
Synthesis begins by 28th weeks of gestation
Stored in lamellar bodies
Neonatal atelectasis is also known as respiratory distress syndrome (RDS) in newborns and again as already discussed this deals with decreased surfactant in fetal lungs. What three predisposing factors in the mother during pregnancy can lead the unborn infant to have decreased surfactant production?
Prematurity
Maternal Diabetes (fetal hyperglycemia stimulates insulin release)
C. section: labor and vaginal delivery leads to increased stress related cortisol secretion and therefore increased surfactant production
(remember that in regards to surfactant, synthesis is increased by cortisol and thyroxine and decreased by insulin)
Neonatal atelectasis has what clinical findings?
Clinical findings:
- -resp distress within a few hours of birth
- -hypoxemia and resp acidosis
- -ground glass appearance on CXR
What are the systemic complications for neonatal atelectasis?
Intraventricular hemorrhage
Patient ductus arteriosus (persistent hypoxemia)
Necrotizing enterocolitis (intestinal ischemia)
Hypoglycemia (Excessive insulin release)
O2 therapy (damage to lungs and cataracts)
What are the various names for Acute Respiratory Distress Syndrome (ARDS)?
Diffuse Alveolar damage
Hyaline Membrane Disease
Acute lung injury
Shock Lung