Term
|
Definition
| the terminal end of the airways |
|
|
Term
| what are the alveoli responsible for |
|
Definition
| gas exchange in the pulmonary circuit; maximizing surface area for exchange |
|
|
Term
| what are the characteristics of alveoli |
|
Definition
| thin walls (one cell thick), specialized for gas exchange; type I cells (exchange of gas); type II cells (produce pulmonary surfactant) |
|
|
Term
| what covers a large portion of the alveoli |
|
Definition
|
|
Term
|
Definition
| a double-walled serous membrane that separates the lung from the thoracic wall |
|
|
Term
| what is the pleural cavity |
|
Definition
| a fluid-filled space between visceral and parietal pleural layers where the fluid provides lubrication |
|
|
Term
|
Definition
| the movement of air in and out of lungs |
|
|
Term
| what is the mechanism of ventilation |
|
Definition
| air flowing down pressure gradients |
|
|
Term
| What pressures are involved in the pressure gradients |
|
Definition
| Atmospheric; intra-alveolar; intrapleural |
|
|
Term
| what is atmospheric pressure |
|
Definition
| the pressure exerted by the weight of air in the atmosphere on objects on earth (~760mmHg at sea level) |
|
|
Term
| how does atmospheric pressure change as altitude is increased |
|
Definition
|
|
Term
| what is intra-alveolar pressure |
|
Definition
| pressure within the alveoli |
|
|
Term
| what creates a communication between the alveoli and the atmosphere |
|
Definition
|
|
Term
| what causes air to flow into alveoli |
|
Definition
| atmospheric pressure being greater than intra-alveolar pressure |
|
|
Term
| what is intrapleural pressure |
|
Definition
| the pressure exerted outside the lungs within the thoracic cavity and is usually subatmospheric (~4mmHg) with no communication with atmosphere and/or alveolar space |
|
|
Term
| what does the intrapleural fluid do |
|
Definition
| it facilitates the movement of the lungs in ventilation as a result of its cohesiveness |
|
|
Term
| what is the role of the thoracic wall |
|
Definition
| it has a tendency to pull outward away from the lungs |
|
|
Term
| what are the lungs made up of and what do they do |
|
Definition
| composed of elastic tissue; tends to pull inward away from the thoracic wall |
|
|
Term
| what is the transmural pressure gradient |
|
Definition
| intra-alveolar pressure; causes the lungs to expand |
|
|
Term
|
Definition
| it is the abnormal state where air enters the intra-pleural cavity (collapsed lung) |
|
|
Term
| what does Boyle's law state |
|
Definition
| Pressure and volume of gas vary inversely at a constant temperature |
|
|
Term
| what does inspiration mean in regards to pressure |
|
Definition
| intra-alveolar pressure is decreased below atmospheric pressure; icreases the volume of the thoracic cage; decrease the intra-alveolar pressure |
|
|
Term
| what are the inspiratory muscles |
|
Definition
| diaphragm and external intercostals |
|
|
Term
| what does the diaphragm do |
|
Definition
| contraction by increasing the volume of the thoracic cage |
|
|
Term
| what do the external intercostals do |
|
Definition
| contraction moves the sternum up and out, moving ribs to increase the volume |
|
|
Term
|
Definition
| the contraction of the diaphragm and external interscostals resulting in an increase in the volume of the thoracic cage and a decrease in intra-alveolar pressure |
|
|
Term
| what happens in forced inpiration |
|
Definition
| the sternocleiodomastoid and scalene muscles contract in addition to the diaphragm and external intercostals resulting in a further increase in thoracic cage volume |
|
|
Term
|
Definition
| the quiet relaxation of inspiratory muscles (passive) decreasing the volume and increasing the pressure within alveoli resulting in an expiration of air |
|
|
Term
| what happens in a forced expiration |
|
Definition
| contraction of abdominal muscles and internal intercostals which leads to a further decrease in volume |
|
|
Term
| how is airway resistance in normal healthy individuals |
|
Definition
| airways are maintained in that resistance should not be an issue |
|
|
Term
|
Definition
| how readily the lungs rebound after being stretched |
|
|
Term
|
Definition
| how easily the lungs are stretched; how much change in volume there is for a given change in pressure |
|
|
Term
| what kind of connective tissue is found in lungs |
|
Definition
| elastic connective tissue with elastin fibers present |
|
|
Term
| what does alveolar fluid surface tension do |
|
Definition
| contributes to elastic recoil; resists and forces that increase surface area; reduces compliance; and acts as a pulmonary surfactant produced by Type II cells therefore reducing alveolar surface tension |
|
|
Term
| what is alveolar fluid made of |
|
Definition
| a mixture of lipids and proteins that increase compiance and reduces elastic recoil |
|
|
Term
| what is tidal volume (TV) |
|
Definition
| the volume of air that is moved in and out of the lungs with each quiet respiration (~500ml) |
|
|
Term
| what is inspiratory reserve volume (IRV) |
|
Definition
| the additional volume of air that can be inhaled with a forced inhalation (~3000ml) |
|
|
Term
| what is expiratory reserve volume (ERV) |
|
Definition
| the additional volume of air that can be forcibly exhaled (~1000ml) |
|
|
Term
| what is the residual volume (RV) |
|
Definition
| the amount of air that is left after a forced expiration |
|
|
Term
| what is the total lung capacity (TLC) |
|
Definition
| the sum of all four volumes; TLC=TV+IRV+ERV+RV= ~5700ml |
|
|
Term
| what is the function residual capacity (FRC) |
|
Definition
| the amount left after a quiet expiration; FRC=ERV+RV |
|
|
Term
| what is inspiratory capacity |
|
Definition
| the amount that can be inspired after quiet expiration; IC=TV+IRV |
|
|
Term
| what is vital capacity (VC) |
|
Definition
| the max achievable change in volume; VC=TV+IRV+ERV |
|
|
Term
| How is pulmonary ventilation calculated |
|
Definition
| TV(tidal volume ~500ml)* respiratory rate =~6L/min |
|
|
Term
| what is anatomic dead space |
|
Definition
| the airways not involved in air exchange |
|
|
Term
| how is pulmonary ventilation calculated |
|
Definition
| TV(~350ml)*respiratory rate(12/min) = ~4.2L |
|
|
Term
| in the alveoli what happens with a decrease in O2 |
|
Definition
| it leads to pulmonary vasoconstriction |
|
|
Term
| in the alveoli what happens with an increase in CO2 |
|
Definition
|
|
Term
| What does Dalton's Law of Partial Pressures state |
|
Definition
| the total pressure of a mixture of gases is the sum of the individual pressures of each gas and each individual pressure of a gas is a partial pressure |
|
|
Term
| What are the partial pressures of the gases in the atmosphere |
|
Definition
| N2-79%(600mmHg); O2-21%(159mmHg); CO2-0.04%(0.03mmHg); H20-0.46%(3.7mmHg) |
|
|
Term
| what are the partial pressures of the gases in the alveoli |
|
Definition
| N2(563mmHg); O2-21%(159mmHg); CO2-0.04%(40mmHg); H2O-0.46%(47mmHg) |
|
|
Term
| In blood entering the pulmonary capillaries what are the partial pressures of O2 and CO2 |
|
Definition
|
|
Term
| In blood entering pulmonary capillaries what happens to O2 and CO2 |
|
Definition
| gradient favors movement of O2 out of alveoli and CO2 entering the alveoli with near equal amounts of O2 and CO2 being exchanged because CO2 is more soluble |
|
|
Term
| what happens at respiring systemic tissues |
|
Definition
| O2 out of the vessel and CO2 into the vessel |
|
|
Term
| what makes up the respiratory membrane/surface |
|
Definition
| alveolar wall; fused basal lamina; wall of the capillary (1 endothelial cell thick) |
|
|
Term
| what happens in pulmonary edema |
|
Definition
| the barrier thickens and pneumonia |
|
|
Term
| how is oxygen transported |
|
Definition
| 1.5% is dissolved in the blood and 98.5% is bound to hemoglobin |
|
|
Term
| with the dissolved O2 at 100mmHg Po2 what is happening |
|
Definition
| there is 3ml O2/1L of blood; 15ml of O2/min; 250ml/min of O2 is being consumed |
|
|
Term
| what are the characteristics of hemoglobin |
|
Definition
| it's a tetramer (4 subunits); each subunit contains 1 heme group; iron atom at center of porphyrin ring; can bind up to 4 O2 |
|
|
Term
| when is hemoglobin considered fully saturated |
|
Definition
| when it is fully loaded with O2 (4 O2 molecules) |
|
|
Term
| What is the reaction for oxygen binding to hemoglobin |
|
Definition
| O2+hemoglobin <--> oxyhemoglobin |
|
|
Term
| What are the effects of different partial pressures of O2 on hemoglobin saturation |
|
Definition
| at Po2=100mmHg the hemoglobin is 98.5% saturated while at Po2=40mmHg the hemoglobin is 75% saturated |
|
|
Term
| what are the factors that decrease hemoglobin affinity for O2 (right shift of curve) |
|
Definition
| increase in temperatures; increase acidity; Bohr shift due to conformation change in hemoglobin molecule; binding to hemoglobin molecule; an increase in CO2 (causes formation of carbonic acid); CO2 also combines with hemoglobin; 2,3-bisphosphoglycerate; presence of CO |
|
|
Term
| what reaction shows how CO2 affects hemoglobin binding |
|
Definition
| CO2+H2O<-->H2CO3<--> H+ HCO3 |
|
|
Term
| how does CO2 combining to hemoglobin reduce O2 affinity |
|
Definition
| it produces a conformational change |
|
|
Term
| how does 2,3-bisphosphoglycerate affect hemoglobin binding with O2 |
|
Definition
| it favors offloading of O2 |
|
|
Term
| how does CO affect hemoglobin binding with O2 |
|
Definition
| it outcompetes O2 at the binding site on hemoglobin |
|
|
Term
|
Definition
| 10% is dissolved in blood; 30% is bound to carbamino compounds (bound to hemoglobin--> carbaminohemoglobin); 60% as bicarbonate |
|
|
Term
| What is the haldane effect |
|
Definition
| when O2 is offloaded from hemoglobin there is an increase in affinity for CO2 to bind |
|
|
Term
| how is oxygen transported |
|
Definition
| 1.5% is dissolved in the blood and 98.5% is bound to hemoglobin |
|
|
Term
| How fast is the is the CO2 to HCO3 reaction and what speeds it up |
|
Definition
| the reaction is slow in plasma but in RBC it can be sped up using carbonic anhydrase |
|
|
Term
| what happens in a chloride shift (hamburger) |
|
Definition
| bicarbonate ion and Cl ion are exchanged |
|
|
Term
| why is the chloride shift important |
|
Definition
| the removal of bicarbonate allows the reaction to proceed to the right (to the left in pulmonary capillaries) |
|
|
Term
| what are the different types of hypoxia |
|
Definition
| hypoxic hypoxia; anemic hypoxia; circulatory hypoxia; histotoxic hypoxia |
|
|
Term
| what happens in hypoxic hypoxia |
|
Definition
| low arterial blood Po2 accompanied by inadequate Hb saturation (decrease in systemic arterial Po2) |
|
|
Term
| what causes hypoxic hypoxia |
|
Definition
| malfunction in gas exchange; insufficient O2 in the air |
|
|
Term
|
Definition
| reduced O2 carrying capicty of the blood (normal systemic arterial Po2) |
|
|
Term
| what causes anemic hypoxia |
|
Definition
| reduction of available Hb to bind O2; decrease in RBC count; mutated Hb; CO poisoning |
|
|
Term
| what is circulatory hypoxia |
|
Definition
| too little oxygenated blood is delivered; usually with normal Po2, Pco2, and Hb |
|
|
Term
| what is histotoxic hypoxia |
|
Definition
| O2 delivery to cell is adequate but the cell can't use the O2 |
|
|
Term
|
Definition
|
|
Term
|
Definition
| respiratory acidosis; hypoventilation (inadequate ventilation) |
|
|
Term
|
Definition
|
|
Term
|
Definition
| hyperventilation; respiratory alkalosis |
|
|
Term
| what is the dorsal respiratory group |
|
Definition
| inspiratory neurons that synapse on inspiratory muscles that cause impulses that initiate excitation and contraction leading to an initiation of inspiration |
|
|
Term
| what is the ventral respiratory group |
|
Definition
| neurons controlling forced inspiration and expiration |
|
|
Term
| what are the peripheral chemoreceptors |
|
Definition
| receptors that detect the variation of the oxygen concentration in arterial blood while also monitoring arterial CO2 and pH |
|
|
Term
| where are the peripheral chemoreceptors found |
|
Definition
| in the aortic arch and carotid bifurcation |
|
|
Term
| what are the peripheral chemoreceptors sensitive to |
|
Definition
| large decreases in arterial Po2 (should be 100mmHg but sensitive if below 60mmHg); hypercapnia (if Pco2 increased by 40mmHg) |
|
|
Term
| what do the central chemoreceptors do |
|
Definition
| detect changes in [H] especially increased acidity (mostly respiratory acidosis; detects hypercapnia to monitor CO2 crossing the BBB that will then turn to bicarbonate |
|
|
Term
| where are the central chemoreceptors located |
|
Definition
| in the medulla within the BBB |
|
|
Term
| what are irritant reflexes |
|
Definition
| sneeze (result of irritant in nasal passage); cough (result of irritant in trachea) |
|
|
Term
| what is the inflation reflex |
|
Definition
| the Hering Brewer Reflex which says that there are stretch receptors in the lung that fire when the lungs are stretched too far to prevent over-inflation |
|
|
Term
| what does the cerebral cortex have to do with breathing |
|
Definition
| there is some cortical (conscious) control over breathing |
|
|
Term
| that is the importance of the hypothalamus in breathing |
|
Definition
| control pain, fear,emotion, and body temperature; all of which increase respiration as they increase |
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