Term
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Definition
-inc PaCO2
-aka hypoventilation |
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Term
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Definition
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Term
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Definition
| -dec O2 delivered to the tissue |
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Term
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Definition
-bluish color of tissue
-deoxygenated hemoglobin (>3-5 g/dL) |
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Term
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Definition
| -perception of difficulty breathing |
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Term
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Definition
| -V of gas passing into and out of lung w/ each resp cycle |
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Term
| Definition: minute ventilation |
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Definition
| -V of gas passing in & out of lung in 1 min |
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Term
| In general, what are the physical defenses of the resp system? |
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Definition
-air flow patterns & anatomic barries: nasal turbinates, branching airways, larynx
-epi barrier
-mucuciliary clearance
-cough and sneeze: reflexes to remove airway debris |
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Term
| What do the central chemoreceptors in the medulla respond to during respiration control? |
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Definition
| -CSF inc PaCO2 (dec CSF pH) |
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Term
| What do the peripheral chemoreceptors in the carotid body respond to during resp control? |
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Definition
-dec PaO2 (<60 mmHg)
-inc PaCO2
-inc H+
-dec perfusion rate |
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Term
| How does the medulla affect central neuronal control of breathing? |
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Definition
-breath is generated
-insp & exp cetners |
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Term
| How does the pons affect central neuronal control of breathing? |
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Definition
-pneumotactic center: control of rhythm b/n breaths
-apneustic center: prevents overfillling of lungs |
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Term
| Where are the lower motor neurons that control resp peripherally? |
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Definition
-phrenic n: caudal cervical
-intercostal nn: T2-T12 |
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Term
| Which mm are important for breathing? |
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Definition
-diaphragm
-intercostal mm
-laryngeal/pharyngeal mm |
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Term
| Which mm are a part of active expiration due to dz or exercise? |
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Definition
-abdominal mm: rectus, abdominus, obliqures, transverse abdominus
-intercostal mm |
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Term
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Definition
| -tidal exchange of air b/n lungs and atmosphere |
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Term
| What are the purposes of ventilation? |
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Definition
-oxygenation of blood: deliver O2 to tissue, oxidative phsophoryaltion
-expel CO2: end pdt of aerobic metabolism, acid-base
-heat exchange: esp important in dogs |
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Term
| What factors are required to O2 to be delivered to the tissues? |
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Definition
-oxygenation of blood
-hemoglobin concentration
-hemglobin function
-CO & peripheral vasculature |
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Term
| What are the components that gas must traverse? |
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Definition
-surfactant
-resp epi
-resp epi BM
-interstitium
-capillary endo BM
-capillary endo |
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Term
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Definition
| -gas exchange is dependent on: SA of tissue + difference in partial pressure + diffusion barrier thickness + diffusion coefficient |
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Term
| What determines the diffusion coefficient? |
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Definition
-MW
-soubility of gas in the tissue |
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Term
| How does the diffusion coefficient of CO2 compare to that of O2? |
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Definition
| -it is 20 higher thus diffuses super easily |
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Term
| Gas exchange is proportional to what? |
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Definition
-tissue area
-differencei n partial P
-diffusion coefficient |
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Term
| Gas exchange is inversely proportional to what? |
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Definition
| -thickness of diffusion barrier |
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Term
| What are the 5 big causes of hypoxemia? |
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Definition
-hypoventilation
-Ventilation-perfusion mismatch
-diffusion barrier impairement
-low fraction of inspired O2
-right ot left shunt |
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Term
| How does hypoventilation lead to hypoxemia? |
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Definition
| -causes hypercapnea due to lack of CO2 ocnc gradient |
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Term
| What are some examples of etiologies that cause inc upper airway resistance leading to hypovenitlation to hypoxemia? |
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Definition
-laryngeal paralysis
-laryngeal edema/mass
-tracheal collapse
-tracheal mass/hypoplasia
-brachycephalic syndrome |
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Term
| What are some other examples of etiologies behind hypoventilation? |
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Definition
-dec vital capacity: pleural dz, thoracic wall dz, abdominal distension
-severe pain: rib fractures
-neuromuscular dz: CNS dz, tick paralysis, MG, phrenic n damage
-drugs: barbiturates, opioids |
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Term
| What are some common etiologies behind V-Q mismatch? |
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Definition
-severe parenchymal dz
-pneumonia
-pulmonary thromboembolism
-pulmonary edema
-pulmonary hemorrhage |
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Term
| What are some dz that inc thickness of diffusion barrier? |
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Definition
-pulmonary edema
-pulmonary fibrosis
-neplasia |
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Term
| What are some etiologies behind low FiO2? |
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Definition
-complications w/ anesthesia
-very high altitudes |
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Term
| What are some examples of right to left shunts? |
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Definition
-right to left PDA, tetraology, etc
-intrapulmonary A-V fistulas |
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Term
| How does a right to left shunt cause hypoxemia? |
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Definition
| -some blood shunts past the lungs thus returning to systemic circulation w/out being oxygenated |
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