Development
Branchial pouches are derivatives of what germ layer?
Endoderm
pouches are on the inside & so is endoderm
cartilage and goblet cells extend to the end of what part of what lung location
bronchi
Pneumoconioses, such as silicosis, would result in what type of pattern on a flow volume loop?
Restrictive Pattern (flow volume loop shifted to the right)
FEV1 decreases but FVC decreases by much more, therefore the FEV1/FVC ratio increases. The TLC in these conditions decreases, as well as compliance.
In Image 2, why is the red flow-volume loop smaller than the grey (normal) flow-volume loop?
Reduced lung volume on maximal inspiration due to reduced pulmonary compliance
This shows a restrictive flow-volume loop. The problem with restrictive lung diseases is you can't get enough air in (hence the significantly reduced inspiratory flow rate) because of reduced pulmonary compliance. This inevitably results in a smaller size (yet preserved flow rate) of the expiratory portion of the loop because there's less air to push out, but no problem with pushing it out. The curve is narrower because of diminished TLC from reduced lung compliance.
A patient presents to the clinic with fingernail clubbing and pain in their right hand that has progressed for 7 months. They also have an unintentional weight loss with no fever. The patient has no smoking history and resides in a basement. Upon further examination, the patient's face and neck seems to be very red with some JVD, which gets worse when raising the arms above the head. What is the condition and likely associated cancer of this patient?
Hypertrophic osteoarthropathy with adenocarcinoma
Adenocarcinoma is related to radon gas exposure (basement), is the most common cancer in nonsmokers, and can induce fibrovascular proliferation which induces hypertrophic osteoarthropathy. This cancer is also associated with SVC syndrome due to Pancoast tumor impingement on the SVC, and a (+) Pemberton sign is worsening of the facial plethora with raising the arms. The associated proto-oncogenes with adenocarcinoma include KRAS, EGFR, and ALK.
What cranial nerve is derived from the 1st branchial arch?
Cranial Nerve V3
the first arch gives rise to the mandible, maxillary process, malleus, incus, muscles of mastication, and is associated with the branch of the trigeminal nerve that supplies these muscles with motor innervation.
In image 1, which arrow corresponds to the type of cell that TB resides within?
Arrow 3: Dust Cells (Alveolar Macrophages)
Describe the Cl- channel protein (location & state) in a patient with two copies of the Phe508 mutation
This Cl- channel would be misfolded and sequestered to the RER, NOT the plasma membrane (where it normally should go)
F508 is the most common mutation in the autosomal recessively-inherited cystic fibrosis. This causes hyposecretion of Cl- in the lungs/GI tract (sticky mucus -> mucous plugging -> recurrent pneumonia) and hypersecretion of Cl- in the sweat (salty sweat -> diagnose CF with sweat test >60). This condition is usually treated with a combination therapy lumacaftor/ivacaftor.
Patients with COPD will be in a chronic state of what acid-base physiology (metabolic vs respiratory, alkalosis vs acidosis)?
Chronic respiratory acidosis
COPD patients are chronic CO2 retainers, this they will have chronically high CO2 and bicarb, with the pH either being low or compensated back into the normal range
Given the CXR in image 4 in a patient with a history of working in a shipyard 25 years prior, what classical histological finding would you expect to see on pulmonary biopsy?
Ferruginous Bodies
This CXR and occupational exposure is classic for asbestos exposure causing mesothelioma, a pleural tumor of mesothelial cells. CXR is classic for pleural or supradiaphragmatic plaques. Ferruginous bodies are golden-brown fusiform rods resembling dumbells.
What organelle is diminished in Neonatal Respiratory Distress Syndrome?
Lamellar Bodies
lamellar bodies, within Type II pneumocytes, produce and store surfactant. In NRDS, there are decreased lamellar bodies thus decreased production of surfactant. This increases the surface tension on the tiny alveoli and subject the to atelectasis.
A patient presents with erythema nodosum, arthritic pain and cough. The pathogen on image 5 is identified from a sputum culture. Where would you expect this patient to have a recent travel history to?
Southwest US
The image shows coccidiomycosis spherules of endospores, which is a fungi endemic to the Southwestern US and is associated with earthquakes, erythema nodosum, skin/lung involvement that may spread to the bone/meninges.
A 50 year old man has an 8 month history of a dry, unproductive cough. On exam, he has dry inspiratory crackles bilaterally and a loud P2. Chest x-ray shows a reticulonodular pattern. What are the two "interchangeable" names for this condition and what change would you expect in his LFTs?
Usual interstitial pneumonia/idiopathic pulmonary fibrosis (as evident by an unexplained and prolonged history of cough, loud P2 (pulmonary HTN), and reticulonodular (aka "honeycombing") scan. You'd expect to see either a stable or increased FEV1/FVC ratio (restrictive pattern). Lung biopsy would give an affirmative diagnosis after a high-resolution CT scan. Treatment for this includes pirfenidone (anti-fibrotic) and a lung transplant.
A 70 year old healthy non-smoker would have which changes in A-a gradient, arterial PO2, and TLC relative to a 20 year old healthy non-smoker.
Increased A-a gradient
Decreased PO2
Increased TLC
The lungs experience obstructive changes as a natural process of aging
What type of tumor presents with tachycardia, flushing, and diarrhea, stains positive for chromogranin A, and is initially diagnosed with 5-HIAA?
Bronchogenic Carcinoid Tumor
These pulmonary nodules secrete serotonin (or a derivative) and cause carcinoid syndrome. They are neuroendocrine tumors that have an initial diagnostic step of urinary 5-hydroxy indole acetic acid.
An infant presents with poor feeding and respiratory difficulty with decreased bowel sounds in the abdomen but increased bowel sounds in the left pleural space. Lung sounds cannot be appreciated. What is the mechanism of this child's condition?
This infant has a congenital diaphragmatic hernia, which is caused by failure of formation of the pleuroperitoneal membranes. It occurs with gastric contents herniated into the left hemithorax and CXR may show "cystic"-appearing areas (loops of bowel) in the left chest space.
What is the condition in image 6 and how do you know?
Asthma
smooth muscle thickening and eosinophils/lymphocytes with goblet cells producing mucus in the bronchiolar columnar epithelium
A 22 year old woman who has never smoked comes in with a loud P2 and tricuspid regurgitation. She has no pitting edema or JVD. What gene is typically mutated in this condition and what is the traditional medication associated with its treatment?
This is primary pulmonary hypertension, which is usually due to a mutation in the BMPR2 gene (which codes for inhibition of vascular smooth muscle proliferation). A key feature of this condition is increased endothelin-1, which is treated with the receptor inhibitor Bosentan.
A patient with severe tachycardia and tachypnea with increased respiratory effort and inability to form a full sentence makes you suspicious of ARDS. You take their blood gasses on 2L/min O2 and get a PACO2 of 72, PaO2 of 42, and an Hb of 15. What stage of ARDS are they in?
Moderate! Their PaO2 to FiO2 ratio (42/.28) is 150, which falls in the moderate category. Severe is less than 100, mild is 201-300, and normal is above 300.
What type of cell (general and specific) are the origin cells for small cell lung cancer?
Neuroendocrine aka Kulchitsky cells
these cancers stain positive for chromogranin A (among others) because they're neuroendocrine
A 1.5 year old child was rushed to the ED by his parents who found him on his play mat barely breathing. He is using assistant respiratory muscles and is in obvious distress. On exam, he has unilateral hyperresonance and CXR shows an ipsilateral tracheal shift. What is the likely cause of this condition?
Foreign body aspiration
the child was likely crawling on the ground and swallowed something he shouldn't have
The cancer in image 3 would cause what change in PTH levels in the lung?
Decreased
This is squamous cell carcinoma (keratin pearls). One of the paraneoplastic syndromes associated with this cancer is PTHrP. This peptide acts like PTH and raises Ca2+ levels. The increased Ca2+ will have a negative feedback effect on the endogenous secretion of PTH, therefore levels of true PTH in the lung will be low.
A condition is characterized by non-caseating granulomas in lung tissue made of epithelioid macrophages. It may present in a young Black woman with dry cough, shin redness, and a low grade fever. What is the mechanism of the hypercalcemia associated with this condition?
This is sarcoidosis (idiopathic non-caseating granulomas common in African American women, associated with erythema nodosum and bilateral hilar lymphadenopathy on CXR). In this condition, the epithelioid macrophages (aka histiocytes aka activated macrophages) secrete 1alpha-hydroxylase, which activates vitamin D. Hypervitaminosis D then stimulates the small bowel to increase its absorption of calcium. In these patients, you will see a low PTH and a high 1,25-(OH)2-D3 (active vitamin D). It's also associated with lupus pernio and is treated with oral prednisone.
The DLCO is __[increased/decreased]__ in every pulmonary pathology except for ______, in which is is __[increased/decreased]__.
The DLCO is __decreased__ in every pulmonary pathology except for __asthma__, in which is is __increased__.
DLCO is diffusion capacity of the lungs for carbon monoxide. It reflects the extent to which gas exchange is occurring in the pulmonary capillaries.
this is believed to be due to a transient increase in blood flow throughout the pulmonary capillaries and additional hyperinflation during acute episodes.
List three of the paraneoplastic syndromes associated with Small Cell Lung Cancer.
SIADH (tumor secretes ADH)
Cushing Syndrome (due to tumor secretion of ACTH)
Lambert-Eaton Syndrome (production of antibodies against pre-synaptic Ca2+ channels)
Cerebellar dysfunction/ataxia (anti-Hu antibodies)