Pulm Physiology Review Flashcards
What chemical Factor is the main driver of respiration?
PCO2 stimulates central chemoreceptors
What is the pathway to increase PO2?
General Chemoreceptor stim Central Pattern Generator and Higher CNS Spinal Cord Resp Muscles Chest Wall, diaphragm, airways Inc Ventilation
How is resistance to Airflow increased in Obstructive Lung diseases?
Inflmmation of Bronch Epi- bronchitis
Secretions from epithelium (asthma, infection, Dec cilia)
Constriction of smooth muscle-asthma
Physical Blockade: Tumors, Apiration
What are the diseases caused by Obstructions from conditions in the airway wall?
Asthma
Acute Bronchitis
Chronic Bronchitis
What are the diseases caused by Obstructions from loss of lung parenchyma?
Emphysema
What are the diseases caused by Obstructions fromobstruction of the airway lumen?
Bronchiectasis Bronchiolitis Cystic Fibrosis Acute Tracheobronchial Obstruction Epiglottitis Croup
What is the composition of the Respiratory membrane?
Fluid layer with surfactant Alveolar Epi Epithelial Basement Mem Interstitial Space Capillary basement mem. Capillary endothelial mem
What is Goodpasture’s syndrome?
AI disease that causes Destruction of Collagen in the alveolar membrane
What are changes of the Lung interstitium in disease?
Normally very small.
Becomes enlarged with inflammatory cells and edema leading to interference with gas exchange
What is the effect of partial pressure difference between alveoli and blood?
Positive relationship with Rate of diffusion of gas across the respiratory membrane
What will increase Delta P?
High altitude
O2 mask
Fi O2
Restrictive lung disease
What is the relationship between Surface area/distance between membranes and Diffusion?
Area: Positive relationship
Distance: Negative Relationship
What happens inside the lung during left heart failure?
Hydrostatic Pressure increases in the pulmonary capillaries which will drive fluid into the Pleural Space. Diffusion rate will decrease.
What are causes of pleural effusion?
Congestive Heart failure
Decreased microvascular Oncotic Pressure
Decreased pleural pressure (atelectasis)
Blockade of lymphatic drainage (tumors)
What is Lung Compliance?
How much the lung expands in response to each unit of transpulmonary pressure?
Reflects lung distensibiity
What are determinants of Lung compliance?
Elastic Forces of lung tissue
Elastin and Collagen
Elastic Forces of Surface tension
What is the relationship between Compliance and Elasticity?
They are the inverse of each other
What are the (Restrictive) lung parenchyma disorders?
Fibrotic Interstitial Lung Diseases
Atelectatic Disorders
What are the (Restrictive) Pleural Space disorders?
Pneumothorax, pleural effusion
What are features of the Pulmonary Circulation?
Largest Vascular Bed
Highly Compliant Vessels
Accomodates entire Cardiac OP
What are features of the Bronchial Circulation?
1-2% of cardiac output
empty into pulmonary veins systemic circulation
Generates Physiological Shunt
What is the pulmonary vascular response to hypoxia?
Vasoconstriction
walls thicken over time
Right Heart Hypertrophies in response to increased resistance
What is the average normal V/Q ratio?
0.8
can be as high as 1
Which Lung volume cannot be measured by Spirometry?
Residual Volume
Generated within the first few breaths of life.
Reduces effort to initally expand the lung
