Term
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Definition
| breathing: movement of air into and out of the lungs |
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Term
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Definition
| O2 and CO2 exchange between the lungs and the blood. Influenced by partial pressure gradients and gas solubilities, ventilation-perfusion coupling, structural characteristics of the respiratory membrane |
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Definition
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Definition
| O2 and CO2 exchange between systemic blood vessels and tissues |
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Term
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Definition
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Term
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Definition
| conduits to gas exchange sites |
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Term
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Definition
| diaphragm and other muscles that promote ventilation |
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Term
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Definition
air passages undergo 23 orders of branching
first is left and right primary bronchi
each of these branches into lobar bronchi (3 on right, 2 on left), then branches into segmental tertiary then branches a ton |
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Term
| Changes in structure from bronchi to bronchioles |
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Definition
cartilage rings give way to plates then disappears
Epithelium changes from pseudostratified to cuboidal
Cilia and goblet cells become sparse
Relative amount of smooth muscle increases |
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Term
| 300 million alveoli. What is this good for? |
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Definition
| Huge surface area for gas exchange |
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Term
| What do alveolar pores do? |
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Definition
connect adjacent alveoli
allow air pressure throughout the lung to be equalized |
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Term
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Definition
| very very very thin, make of alveolar & capillary walls & their fused basement membranes |
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Term
| Epithelium that makes up alveolar walls |
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Definition
| type I epithelial cells and they secrete angiotensin converting enzyme (ACE) |
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Term
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Definition
| secreted by type II cells of alveolar walls, prevents alveoli and tiny bronchioles from collapsing during exhalation |
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Term
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Definition
| keep the alveolar surface sterile |
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Term
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Definition
thin double-layered serosa, parietal pleura on thoracic wall, visceral pleura on external lung surface
pleural fluid between the two layers, which reduces friction and creates a pressure gradient |
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Term
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Definition
| 760 mmHg at sea level. Respiratory pressures are relative to this. Negative is less than 760, positive is more |
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Term
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Definition
| pressure in the alveoli, always eventually equalizes with P(atm) |
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Term
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Definition
pressure in the pleural cavity, always less than P(atm)
elastic recoil of lungs and surface tension of alveolar fluid promote lung collapse and elasticity of the chest wall promotes lung enlargement |
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Term
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Definition
| lung collapse: due to plugged bronchioles (collapse of alveoli) or wound that admits air into pleural cavity (pneumothorax) Happens when P(ip) = P(pul) |
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Term
| How does pulmonary ventilation happen |
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Definition
Mechanical processes lead to volume changes
volume changes lead to pressure changes
pressure changes lead to gases flowing to equalize pressure |
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Term
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Definition
| The relationship between the pressure and volume of a gas. Pressure varies inversely with volume |
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Term
| Factors influencing pulmonary ventilation |
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Definition
airway resistance
alveolar surface tension
lung compliance |
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Term
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Definition
friction is the major source of nonelastic resistance
flow = change in pressure/ resistance |
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Term
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Definition
| attracts liquid molecules to one another at a gas-liquid interface. Surfactant resists surface tension and a lack of this causes infant breathing problems |
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Term
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Definition
| pressure created is directly proportional to the surface tension and inversely proportional to the radius of the alveolus. Without surfactant, small alveoli would dump their air into larger alveoli, but this doesn't actually happen |
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Term
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Definition
| A measure of the change in lung volume that occurs with a given change in transpulmonary pressure. Normally high due to distensibility of the lung tissue and alveolar surface tension |
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Term
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Definition
| volume of the conducting zone conduits (about 150 mLs) |
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Term
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Definition
| alveoli that cease to act in gas exchange due to collapse or obstruction |
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Term
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Definition
used to measure respiratory volumes
can distinguish between obstructive pulmonary disease and restrictive disorders |
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Term
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Definition
| total amount of gas flow into or out of the respiratory tract in one minute |
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Term
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Definition
| gas forcibly expelled after taking a deep breath |
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Term
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Definition
| the amount of gas expelled during specific time intervals of the FVC |
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Term
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Definition
| amount of air inhaled or exhaled with each breath under resting conditions |
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Term
| inspiratory reserve volume |
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Definition
| amount of air that can be forcefully inhaled after a normal tidal volume inhalation |
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Term
| expiratory reserve volume |
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Definition
| amount of air that can be forcefully exhaled after a normal tidal volume exhalation |
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Term
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Definition
| amount of air remaining in the lungs after a forced exhalation (has to be there so your lungs don't collapse |
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Term
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Definition
| maximum amount of air contained in lungs after a maximum inspiratory effort |
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Term
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Definition
| maximum amount of air that can be expired after a maximum inspiratory effort |
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Term
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Definition
| maximum amount of air that can be inspired after a normal expiration |
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Term
| functional residual capacity |
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Definition
| volume of air remaining in the lungs after a normal tidal volume expiration |
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Term
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Definition
| increases in TLC, FRC, and RV may occur as a result of obstructive disease. Increased airway resistance, such as bronchitis |
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Term
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Definition
| reduction in VC, TLC, FRC, and RV, reduction in total lung capacity due to structural or functional lung changes such as fibrosis or TB |
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Term
| Dalton's law of partial pressures |
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Definition
| total pressure exerted by a mixture of gases is the sum of the pressures exerted by each gas. The partial pressure of each gas is directly proportional to its percentage in the mixture |
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Term
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Definition
| when a mixture of gases is in contact with a liquid, each gas will dissolve in the liquid in proportion to its partial pressure. The amount of gas that will dissolve in a liquid depends upon its solubility. COw is 20X more soluble than O2 and very little N2 dissolves in water |
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Term
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Definition
| partial pressure gradient for O2 in the lungs is steep, so it can go through 3x as quickly, but still adequately oxygenates |
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Term
| ventilation-perfusion coupling |
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Definition
ventilation: amount of gas reaching the alveoli and perfusion: blood flow reaching the alveoli
Changes in PO2 in the alveoli causes changes in the diameters of the arterioles
Changes in PCO2 in the alveoli cause changes in the diameters of the bronchioles |
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Term
| O2 transport in the blood |
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Definition
1.5% dissolved in blood plasma
98.5% loosely bound to hemoglobin (4 O2 per Hb) |
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Term
| Factors that effect rate of loading and unloading of O2 |
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Definition
| pressure of O2, temperature, blood pH, pressure of CO2, concentration of BPG |
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Term
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Definition
| release of O2 in response to low pH |
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Term
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Definition
| inadequate O2 delivery to tissues because of: too few RBC's, abnormal or too little HB, blocked circulation, metabolic poisons, pulmonary disease, carbon monoxide |
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Term
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Definition
| low arterial PO2 results in low tissue O2. Level of Hb is normal, caused by low air PO2, low ventilation, low alveolar diffusion, abnormal ventilatory-perfusion rate |
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Term
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Definition
| low tissue O2 due to low carrying capacity of blood, usually Hb is low, PO2 is normal, CaO2 is reduced. Caused by low or abnormal Hb, carbon monoxide poisoning |
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Term
| Ischemia (stagnant) hypoxia |
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Definition
| low tissue O2 due to low blood flow. Hb, CaCO2, and arterial P(O2) is normal |
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Term
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Definition
| inability of tissue to utilize O2. Most common cause is cyanide poisoning |
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Term
| transport of CO2 in blood |
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Definition
7-10% dissolved in plasma
20% bound to globin of Hb (carbaminohemoglobin)
70% transported in plasma as bicarbonate ions (HCO3-) |
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Term
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Definition
the amount of CO2 transported is affected by the P(O2)
At the tissues, as more carbon dioxide enters the blood, more oxygen dissociates from hemoglobin (Bohr effect) |
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Term
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Definition
| changes in respiratory rate can alter blood pH, HCO3- in plasma is the alkaline reserve of the carbonic acid-bicarbonate buffer system |
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Term
| Carbon monoxide poisoning |
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Definition
| colorless, odorless gas, binds heme group of Hb 200x as strong as the binding of oxygen. Treated by administering pure oxygen. A concentration of 0.1% of CO will decrease oxygen carrying capacity by 50% |
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Term
| Neural control of respiration |
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Definition
involves neurons in the reticular formation of the medulla and pons. Dorsal respiratory group integrates input from peripheral stretch & chemoreceptors
Ventral resperatory group sets eupnea, phrenic & intercostal nerves, expiratory nerurons inhibits the inspiratory neurons |
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Term
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Definition
| increased depth and rate of breathing that exceeds the body's need to remove CO2, causes CO2 levels to decline (hypocapnia) |
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Term
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Definition
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Term
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Definition
| abnormally uncomfortable awareness of breathing (labored breathing with shortness of breath) |
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Term
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Definition
| increased alveolar ventilation in relation to metabolic rate |
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Term
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Definition
| decreased alveolar ventilation in relation to metabolic rate |
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Term
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Definition
| cessation of respiration in the resting expiratory position |
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Term
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Definition
| cessation of respiration in the inspiratory position |
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Term
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Definition
| increase in P(CO2) tension above normal |
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Term
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Definition
| decrease in P(CO2) tension below normal |
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