Week 1 Block 15: BMR Flashcards
Pulm Test taken 5/12/2014 Test reviewed 5/13/2014
Calculate probability: Husband (cystic fibrosis) and Wife (unaffected but daughter of 2 heterozygous parents) will have child with cystic fibrosis
(1) Probability Wife is carrier = 2/3 (since she’s already known to be unaffected, can discount aa phenotype and count heterozygotes out of remaining phenotype) (2) Probability of child with CF = 1/2 (based on punnett square of heterozygote wife and homozygous recessive husband) (3) Multiply probabilities = 2/3*1/3 = 2/6 = 1/3
Change to phosphatidylcholine v. sphingomyelin over 20-40 weeks of gestation
Phosphatidylcholine (lecithin)»_space; Sphingomyelin, L/S ratio >= 2
Pulmonary Roles/Fxns of, particularly as it relates to alveoli/respiratory epithelium: I. Type II pneumocytes II. Clara cells III. Alveolar macrophages IV. Goblet cells V. Pseudostratified columnar ciliated epithelium
I. (1) regeneration of alveolar lining following injury (2) surfactant production II. Non-ciliated, secretory constituents of terminal respiratory epithelium. (1) Secrete clara cell secretory protein (CCSP), which inhibits neutrophil recruitment and activation as well as neutrophil-dependent mucin production. (2) They may also be a source of apoproteins assoc. with surfactant and/or precursors of mucin-producing goblet cells III. Lung 1st line defense against foreign particles in air. accumulate in alveolar spaces in disease states like desquamative interstitial pneumonia, but are not known to be precursors to alveolar lining cells. IV. rarely found in respiratory epithelium beyond level of smallest bronchi. normally absent from terminal bronchiolar mucosa and from alveoli. generally considered terminally differentiated mucin-producing cells. V. (of tracheobronchilal tree) becomes simple cuboidal ciliated epithelium at level of respiratory bronchioles. cilia absent from lining of terminal alveolar ducts and sacs.
I. Dx: neonate, bilious vomiting, ab distention, air fluid levels, & small bowel dilatation II. Interpret additional finding (and augment dx): inspissated green mass III. Causative disorder & explanation IV. Risks of death, given causative disorder
I. Small bowel obstruction (SBO) II. Distal ileum has been obstructed by dehydrated meconium. Infant suffering from meconium ileus. III. Cystic fibrosis = most common cause of meconium ileus; abnormalities in chloride, sodium & water transport by ductal epithelium of intestinal mucous glands cause isotonic dehydration of lumen contents & secretion of abnormally viscous mucus into small bowel IV. In US, cardiorespiratory complications (e.g., pneumonia, bronchiectasis, bronchitic obstructive pulmonary disease, and cor pulmonale) account for 80% of deaths due to CF
Mechanism of damage behind lung abscess
Tissue damage and resultant abscess formation primarily caused by lysosomal enzyme release from neutrophils and macrophages
(1) Dx: paroxysmal episodes of breathlessness, wheezing in young patient (unrelated to ingestion of aspirin, pulmonary infection, inhaled irritants, stress, and/or and exercise) (2) Interpret additional findings: sputum microscopy granule-containing cells and crystalloid masses (3) Cytokine involved & why
(1) Strong suspicion for extrinsic allergic asthma (2) Eosinophils (granule-containing cells) & Charcot-Leyden crystals (crystalloid bodies, which contain eosinophil membrane protein) (3) Chronic eosinophilic bronchitis in asthmatics involves bronchial wall infiltration by numerous activated eosinophils, largely in response to IL-5 released by allergen-activated Th2 cells
I. Define Cheyne-Stokes respiration II. Context(s) in which it is commonly seen III. Clinical/Prognostic value IV. Mechanism
I. Cyclic breathing in which apnea is followed by gradually increased tidal volumes, and then gradually decreasing tidal volumes until next apneic period. II. Cardiac disease (e.g., advanced congestive heart failure) and neurologic disease (e.g., stroke, brain tumors, traumatic brain injury) III. Frequently a poor prognostic sign in individuals with either neuro or cardio disease IV. Slow respiratory feedback loop with enhanced respiratory response to PaCO2 levels: during start of period of apnea, PaCO2 levels lowest, suppressing respiratory drive. PaCO2 levels then begin to rise because of the apnea. However, slowed feedback delays respiratory response, which allows PaCO2 to rise higher than it normally would. Elevated PaCO2 levels along with increased respiratory sensitivity to PaCO2 cause a hyperventilatory response that beings as PaCO2 levels reach their maximum. This overcompensatory respiratory response then lowers PaCO2 to such an extent that a period of apnea is induced, thus leading to a cycle of hyperventilation and apnea.
I. Give mechanism: increased cardiac output and heart rate but normal PaO2 and PCO2 II. Explain & give what you’d expect to see in venous blood gases
I. Exercise II. Integrated cardiorespiratory response to exercise includes increased HR, CO, & RR in order to balance increased total tissue O2 consumption and CO2 production. Increases coordinated so arterial blood gases remain relatively constant, while venous PO2 decreased and venous PCO2 increased.
Centriacinar Emphysema: I. Association II. Pathogenesis
I. Associated with chronic, heavy smoking II. Intraalveolar release of proteases, especially elastase, from infiltrating neutrophils and from alveolar macrophages
I. Most common mutation in patients with CF II. Wildtype molecular role III. Mutant molecular effect
I. deltaF508 (deletes 3 nucleotides that code for phenylalanine at amino acid position 508) II. CFTR gene codes for cystic fibrosis transmembrane regulator (CFTR) protein, an integral membrane protein III. Abnormal protein folding and failure of glycosylation. CFTR protein degraded before it reaches cell surface, causing its complete absence from apical membrane of exocrine ductal epithelial cells.
I. Puncture what if procedure inserts needle along border of 10th rib at right midaxillary line II. Thoracentesis procedure locations III. Explain risks otherwise
I. Liver II. Above 7th rib in midclavicular line, the 9th rib along midaxillary line, & 11th riba long posterior scapular line III. Lower than these points increases risk of penetrating abdominal strx, and insertion of needle on inferior margin of rib risks striking subcostal neurovascular bundle
(1) Dx: smoker complains of worsening exertional dyspnea, labs show decreased serum anti-protease activity (2) Give PFTs: a) FEV1/FVC b) Total lung volume c) Diffusing capacity
(1) Panacinar emphysema (2) a) Decreased b) Increased c) Decreased
(1) Organ that increases vascular resistance as oxygen blood content decreases (2) Explain purpose (3) Underlying mechanism
(1) Lungs (2) Pulmonary vascular bed relatively unique in that hypoxemia causes vasoconstrictive response. Such hypoxic vasoconstriction in small muscular pulmonary arteries occurs in order to divert blood away from underventilated regions of the lung toward more well-ventilated regions. (3) Direct hypoxemia-induced increase in pulmonary artery smooth muscle cytosolic Ca2+ combined with an unidentified endothelium-derived Ca2+ sensitization factor.
Marker (other than histamine release) of mast cell degranulation
Tryptase
(1) Mechanism triggering vasoactive substance release of mast cells (2) Mechanism of nerve desensitization to excessive neurotransmitter stimulation
(1) Cross-linking of multiple membrane-bound IgE antibodies by a specific antigen, resulting in IgE-Fc receptor aggregation on cell surface (2) Receptor internalization
