Pulmonary Flashcards
In the respiratory tree, cartilage and goblet cells extend until where?
Until the end of the bronchi
In the respiratory tree, pseudostratified ciliated columnar cells extend until where then become what?
Extend to beginning of terminal bronchioles then transition to cuboidal cells
The alveoli consist of what kind of cells?
Simple squamous
Elastase is secreted by which pulmonary cells?
Alveolar macrophages
What do Type II pneumocytes do?
Secrete surfactant, cuboidal and clustered, precursors to Type I pneumocytes and other Type II cells. Proliferate during lung damage.
What do Type I pneumocytes do?
97% of alveolar surfaces, line alveoli, squamous, thin for optimal gas exchange
What do Club (Clara) cells do?
Nonciliated low-columnar/cuboidal cells with secretory granules. Secrete a component of surfactant, degrade toxins, and act as reserve cells.
What indicates fetal lung maturity?
Lecithin-to-sphingomyelin ration > 2 in amniotic fluid
What penetrates the diaphragm at level T8?
Vena cava (8 letters)
What penetrates the diaphragm at level T10?
“oesophagus” (10 letters), CN X,
What penetrates the diaphragm at level T12?
Aortic hiatus (12 letters), thoracic duct, azygos vein
What structures is the diaphragm derived from? (lots of things)
Septum transversum, pleuroperitoneal folds (large portion), dorsal mesentary of esophagus, and muscular outgrowth of lateral body wall
What is a normal total lung capacity?
7 L
What is a normal tidal volume?
500 mL
How do you calculate physiologic dead space?
VD = VT x (PaCO2-PECO2)/PaCO2 “Taco Paco PEco Paco”
How do you calculate minute ventilation? (VE)
VE = VT x RR
How do you calculate alveolar ventilation? (VA)
VA = (VT-TD) x RR
Does the T (taut) form of hemoglobin have low or high affinity for O2?
Low - Taut in Tissues
Does the R (relaxed) form of hemoglobin have low or high affinity for O2?
High - Relaxed in Respiratory tract
Describe methemoglobin, how does it present?
Oxidized form of Hb (ferric, Fe3+) that does not bind O2 as readily, but has higher affinity for cyanide. May present as cyanosis and chocolate-colored blood.
How do you treat methemoglobin?
Methylene blue
What is the clinical presentation of cyanide poisoning?
Almond breath, confusion, headache; Cyanide poisons cytochrome C
How do you treat cyanide poisoning?
Use nitrites to oxidize Hb to methemoglobin, which binds cyanide, forming thiocyanate which is renally excreted.
Describe carboxyhemoglobin
Form of Hb bound to CO instead of O2. Causes less O2 binding capacity with a left shift in dissociation curve. Less O2 unloading in tissues. CO poisoning.
Does a curve shift to the right in the oxygen-Hb dissociation curve indicate higher or lower O2 affinity?
Lower
Does a curve shift to the left in the oxygen-Hb dissociation curve indicate higher or lower O2 affinity?
Higher
What are the factors that affect Hb’s affinity for O2?
H+, 2,3-BPG, altitude, temperature, CO2, and exercise
Does an increase in all factors shift the curve right or left?
Right
What are the consequences of a falling level of Hb?
A decrease of O2 content of arterial blood, but no decrease in O2 saturation or arterial PO2
Describe cor pulmonale
Pulmonary HTN causing RV failure (jugular venous distention, edema, hepatomegaly)
What is a normal A-a gradient?
10-15 mmHg
What is the difference between hypoxemia and hypoxia?
Hypoxemia is low arterial O2, whereas hypoxia is low oxygen delivery to tissues
What are the three forms in which CO2 is transported from tissues to the lungs?
HCO3- (90%), Carbaminohemoglobin/HbCO2 (5%), and Dissolved CO2 (5%)
What is the purpose of carbonic anhydrase?
CO2 from tissues enters RBC and carbonic anhydrase catalyzes following reaction: CO2 + H2O –> H2CO3
Where should thoracentesis be performed?
Between 6-8th ribs along midclavicular line, or between 8-10th ribs along midaxillary line, or between 10-12th ribs along paravertebral line
Nasal polyps in children may indicate what disease?
CF
Nasal polyps in asthmatic adults may indicate what?
ASA(Aspirin)-intolerant asthma - 10% of asthmatic adults
Angiofibromas (benign tumors of nasal mucosa) occur in what patient population?
Adolescent males
A PE, specifically fat embolus, presents how?
Hypoxemia, neuro abnormalities, and petechial rash
Why can an amniotic fluid pulmonary embolus lead to DIC?
Amniotic fluid is loaded with tissue thromboplastin which activates the coagulation cascade
What is the imaging test of choice for PEs?
Spiral CT (CT pulm angiography)
Which type of PE usually leads to sudden death?
Saddle embolus
What are lines of Zahn?
Interdigitating areas of pink (platelets, fibrin), and red (RBCs) found only in thrombi formed before death. Helps distinguish pre- and postmortem thrombi.
What are the 2 most common causes of lobar pneumonia?
S pneumo (95%) and Klebsiella (5%)
What is the most common cause of secondary pneumonia?
S aureus
CF patients classically develop pneumonia due to which bug?
Pseudomonas
What are the most common causes of atypical pneumonia?
Mycoplasma (#1), chlamydia, legionella, RSV (infants), CMV (post-transplant), influenza (elderly), coxiella (farmers and vets; Q fever)
Aspiration pneumonia is typically caused by what?
Anaerobic bacteria
On spirometry, what is the hallmark of obstructive lung disease?
Reduced FEV1/FVC ratio
Which two organs does alpha-1 antitrypsin deficiency affect?
Lung- Emphysema
Liver- Misfolded protein accumulates in liver leading to cirrhosis. PiM is normal allele, PiZ is most common mutation. Protein accumulates in ER of hepatocytes and stains PAS-positive.
What is the pathogenesis of chronic bronchitis?
Hyperplasia of mucus-secreting glands in the bronchi –> Reid index (thickness of gland layer/total thickness of bronchial wall) > 50% (normal is
Who gets centriacinar emphysema?
Smokers
Who gets panacinar emphysema?
alpha-1 antitrypsin deficiency
Describe the pathogenesis of asthma
A genetic predisposition plus an allergen induces Th2 phenotype of CD4 T cells. These Th2 cells secrete IL-4 (which converts IgG–>IgE), IL-5 (which attracts eosinophils), and IL-10 (which induces Th2 phenotype proliferation)
Curschmann spirals and Charcot-Leyden crystals are seen in the sputum of which patients?
Asthmatic patients
What are Curschmann spirals and Charcot-Leyden crystals?
Curschmann spirals - shed epithelium forms mucus plugs
Charcot-Leyden crystals - formed from breakdown of eosinophils in sputum
The most severe form of an asthma exacerbation is called what?
Status asthmaticus
What is bronchiectasis?
Chronic necrotizing infection of bronchi leading to permanently dilated airways
Why do patients with sarcoidosis have hypercalcemia?
The non-caseating granulomas contain an enzyme which activates VitD (any disease with many many non-caseating granulomas will present with hypercalcemia)
Familial forms of primary pulm hypertension are associated with inactivating mutations of what gene?
BMPR2
What are plexiform lesions?
Characteristic vascular change of pulm arteries in pulm HTN
In Acute Respiratory Distress Syndrome, what happens to the lung?
Damage to lung-capillary interface results in leakage of proteins into alveoli which reorganize to form hyaline membranes. Hypoxemia and cyanosis develop as a result of thickened membrane.
Which lung cancer may produce PTHrP?
Squamous cell carcinoma
What is the most common lung cancer in non-smokers?
Adenocarcinoma
What is the most common lung cancer in female smokers?
Adenocarcinoma
Bronchioloalveolar carcinoma arises from which cell type?
Clara cells
Carcinoid tumor arises from which cell type?
Neuroendocrine cells
Which lung cancer is chromogranin positive?
Carcinoid tumor (neuroendocrine cells)
How does carcinoid tumor classically present?
Polyp-like mass in the bronchus
What kind of staging is used for primary tumors of the lung?
TNM staging
What is a unique site of metastasis of lung cancer?
Adrenal gland
How does sarcoidosis usually present?
Bilateral hilar lymphadenopathy, noncaseating granulomas, and increased Ca and ACE
Hypersensitivity pneumonitis is which type of hypersensitivity reaction?
Mixed III/IV reaction
What is Caplan syndrome?
Rheumatoid arthritis and pneumoconionses with intrapulmonary nodules
“Ivory white” calcified pleural plaques are indicative of what?
Asbestosis (these are not precancerous)
Ferruginous bodies are associated with what?
Asbestosis
What is anthracosis?
Asymptomatic condition where carbon is trapped in macrophages and hilar lymph nodes
What is the pathogenesis of silicosis?
Macrophages respond to silica and release fibrogenic factors, leading to fibrosis. Silica may disrupt phagolysosomes and impair macrophages, increasing susceptibility to TB. Increased risk of bronchogenic carcinoma.
What is vasomotor rhinitis?
Chronic nasal discharge that worsens with sudden changes in temperature, humidity, or with exposure to odors or alcohol. Headaches, anosmia, and sinusitis are often reported.
What is nasal vestibulitis?
Staphy infection of the internal nares and associated hair follicles. Can cause mucosal edema and nasal congestion.
Which drugs can classically cause interstitial lung disease?
Bleomycin, busulfan, amiodarone, methotrexate)
