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Physiology - Final - Part 1

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davidwurbel7's version from 2015-08-18 03:59

Respiratory Physiology

Question Answer
The difference of the partial pressure of oxygen in the alveoli and the partial pressure of oxygen in the arteryA-a Gradient
Acetylcholine binding to M3 receptor causes bronchoconstriction is due to this branch of the autonomic nervous systemParasympathetic
Bronchodilatation via binding of adgenerics to β2 receptors is the due to this branch of the autonomic nervous systemSympathetic
Zone in which there are no alveoli and no gas exchange occursConducting Zone
Zone in which there are alveoli and gas exchange occursRespiratory Zone
Are large flat cells that form a part of the thin gas diffusion barrierType I Pneumocytes
Produce Surfactant, a substance that reduces surface tension in the alveoli thereby preventing them from collapsingType II Pneumocytes
Alveolar + Capillary membranes formRespiratory Membrane
Surface area X Partial pressure difference x solubility of gas / Distance (Thickness) X MWRate of Diffusion
This is done to inspired air so that by the time it reaches alveoli it is approximately equal to body tempHumidified
There is destruction of alveoli which decreases surface area thereby diffusion of gases across the Respiratory membrane is decreasedEmphysema
There is accumulation of fluid in interstitial space. So diffusion distance increases, thereby decreasing the net rate of diffusionPulmonary Edema
There is bronchiole constriction. Partial pressure gradient is decreased which will decrease rate of gas diffusionBronchial Asthma
Have cartilaginous support which make them semi-rigid (Stiff). Velocity of air greater - Turbulent airflowCentral Airways
No cartilage. Have smooth muscles & are quite compliant. Parallel arrangement – therefore lesser resistance. Velocity of air decreases-Less turbulent airflowPeripheral Airways
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Respiratory rate = 12 - 20 breaths / min
  Anatomic Dead Space = 150 ml
Tidal volume = 500 ml (0.5 Liter)
Question Answer
Vital capacity4500 ml (4.5 Liters)
Volume of air inspired or expired with each normal breathTidal Volume (TV)
Normal value of 500ml (0.5 L)Tidal Volume (TV)
The volume of air inspired with maximal inspiratory effort. It is amount of air inspired in excess of the tidal volumeInspiratory Reserve Volume (IRV)
The volume of air expelled with a forced expiratory effort. It is volume of air expired after tidal expirationExpiratory Reserve Volume (ERV)
Volume of air in the lungs at the end of maximal forced expiration. It is the amount of air that can be never expelled from the lungsResidual Volume (RV)
The total volume of air inspired with maximal inspiratory effort (TV + IRV)Inspiratory Capacity (IC)
Volume of air in the lungs at the end of quiet , passive expiration ( ERV + RV )Functional Residual Capacity (FRC)
Volume of air that is forcibly expired after a maximal inspiration ( TV + IRV + ERV )Vital Capacity (VC) or Forced Vital Capacity (FVC)
Normal value of 4500 ml (4.5 Liters)Vital Capacity (VC) or Forced Vital Capacity (FVC)
Volume of air in the lungs after a maximal inspiration (TV + IRV + ERV + RV)Total Lung Capacity (TLC)
Is the Expiratory flow rate at the peak of FVC.Peak Expiratory Flow Rate (PEFR)
Normal value of 400-500L/minPeak Expiratory Flow Rate (PEFR)
Volume that is forced out during one secondForced Expiratory Volume (FEV1)
Volume of the conducting airways (ends at the level of terminal bronchioles)Anatomical Dead Space
Approximately 150mlAnatomical Dead Space
Includes non-functional alveoli or alveoli containing air but without blood flow in surrounding capillariesAlveolar Dead Space
The volume of the lungs that does not participate in gas exchange i.e. the total dead space in lungsPhysiological Dead Space
VT X PaCO2 – PE CO2 / PaCO2Physiological Dead Space
Is the total volume of air moving in / out of respiratory system per minuteMinute Ventilation (MV)
Tidal volume x breaths per minuteMinute Ventilation (MV)
Volume of air delivered to respiratory zone (alveoli) per minuteAlveolar Ventilation ( AV)
(TIDAL VOLUME – DEAD SPACE ) X Breaths/minAlveolar Ventilation
VCO2 x K / VAPACO2
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Mechanics of Breathing

Question Answer
Active part of breathingInspiration
Passive part of breathingExpiration
Diaphram, External intercostals, Scalenes, Sternocheidomastiods musclesInspiration Muscles
Internal intercostals, Abdominal musclesExpiration Muscles
This ends when Palv=PatmInspiration
The pressure exerted by the air surrounding the bodyAtmospheric Pressure (Patm)
The pressure within the alveoli of the lungsIntrapulmonary Pressure / Intra-Alveolar Pressure (Palv)
The pressure within the pleural cavityIntrapleural Pressure (Pip)
The index of intrapleural pressureEsophageal Pressure
The difference between the alveolar pressure (inside the lungs) and the intra-pleural pressure (outside the lungs)Transmural Pressure
If the transmural pressure is positive, the lung isOpen and Expanded
If the transmural pressure is negative, the lung isClosed and Collapsed
A negative intrapleural pressure indicatesExpansion
A positive Intrapleural pressure indicatesCollapse
Atmospheric pressure = 0. Intrapleural pressure is -8 cm of H2O. Lung recoil force = -5. Alveolar pressure = less than atmospheric pressureInspiration
Atmospheric pressure = 0. Intrapleural pressure is -8 cm of H2O. Lung recoil force = -8. Alveolar pressure = 0End of Inspiration
Atmospheric pressure = 0. Intrapleural pressure is -5 cm of H2O. Lung recoil force = -8. Alveolar pressure = greater than atmospheric pressureExpiration
Atmospheric pressure = 0. Intrapleural pressure is -5 cm of H2O. Lung recoil force = -5. Alveolar pressure = 0. Lung volume is at FRCEnd of Expiration / At Rest
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Lung Compliance

Question Answer
ΔV / ΔPCompliance
Normal value is 0.2L/cm H2ONormal Compliance
More air will flow for a given change in pressureIncrease Compliance
Less air will flow for a given change in pressureDecrease Compliance
Inversely related to ElastanceCompliance
At this point the collapsing force and the expanding point are equal and opposite resulting in no change in the volume of the lungFRC (Equilibrium Point)
The lipid component of surfactantDipalmitoyl Phosphatidyl Choline
The tendency of the lung is toCollapse
The tendency of the chest wall is toExpand
In Fibrosis, this happens to the lung compliance because elastic tissue in lungs is replaced by fibrous tissue which is stifferDecreased Lung Compliance
In Emphysema, this happens to the lung compliance because of the destruction of alveolar walls with loss of elastic recoil of the lungsIncrease Lung Compliance
Lack of surfactant in infants leads to life threatening disorderNeonatal Respiratory Distress Syndrome
Treatment of Neonatal Respiratory Distress Syndrome is administration of this to the mother before the birthGlucocorticoids (Prednisone)
Treatment of Neonatal Respiratory Distress Syndrome is administration of this to the baby after the birthSurfactant
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Determinants of Airway Resistance

Question Answer
Airway which offer maximum resistance to airflowMedium Bronchi
Parasympathetic (+) , Irritants (cigarette smoking), Asthma, Histamine injection causeBronchoconstriction
Sympathetic (+) & Sympathetic agonists (β adrenergic agonistic drugs – Albuterol, TerbutilineBronchodilatation
Ach binds with this receptor on the smooth muscle of the bronchiolesM3
NE binds with this receptor on the smooth muscle of the bronchiolesβ2
Percentage of the FVC in the 1st second (FEV1)80%
Percentage of the FVC in 2nd second (FEV2)95%
Percentage of the FVC in 3rd second (FEV3)97%
Defined as the amount of the air expelled in the 1st secondForced Expelled Volume (FEV1)
The normal FEV1/ FVC ratio is80%
Point at which the different between the alveoli pressure and intrapleural pressureEqual Pressure Point
If equal pressure point occurs in tissues with cartilage rings, this will occur to the airwayRemain Open
If equal pressure point occurs in tissues without cartilage rings, this will occur to the airwayCollapse
Defined as persistent cough with sputum production for at least 3 months in at least 2 consecutive years (3/2 rule)Chronic Bronchitis
Hyperplasia of goblet cells secretions that fill the bronchi & bronchioles, also resulting in thickening of bronchial walls is seen inChronic Bronchitis
An abnormal, permanent enlargement of air spaces distal to terminal bronchioles with destruction of their wallsEmphysema
Bronchial asthma inflammation is caused by release of this by macrophages and leukocytesLeukotrienes
The air sacs, as well as the lung tissue between and surrounding the air sacs, and the lung capillaries, are destroyed by the formation of scar tissuePulmonary Fibrosis
Decreased FVC, increased FRC, increased TLC, increase RV, decreased FEV1Obstructive Lung Disease
Decreased FVC. decreased FRC, decreased, TLC, decreased RV, decreased FEV1Restrictive Lung Disease
In a flow volume loop graph, the graph has shifted to the rightRestrictive Lung Disease
In a flow volume loop graph, the graph has shifted to the leftObstructive Lung Disease
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Alveolar Blood Gas Exchange

Question Answer
The partial pressure of dry air oxygen160 mm Hg
The partial pressure of water vapor in the airway passages47 mm Hg
Total pressure of gas X percentage of gas in atmospherePartial Pressure of Oxygen Formula
PIO2 - PACO2 / RPartial Pressure of Oxygen in Alveoli Formula
PO2 in inspired air - Alveolar PCO2 / Respiratory Exchange Ratio (0.8)Partial Pressure of Oxygen in Alveoli Formula
( Atmospheric pressure - Partial pressure of water vapor ) X Percentage of atmospheric oxygenPO2 in Inspired Air
Amount of blood that enters the left atrium without undergoing oxygenationPhysiological Shunt
Pgas X Solubility of gas in bloodAmount of Dissolved Gas Formula
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Gas Transport

Question Answer
1.5% of oxygen in bloodDissolved
98.5% of oxygen in bloodBound
Oxygen that is responsible for PO2 & diffuses to tissuesDissolved Oxygen
Hb containing O2Oxyhemoglobin
Hb without O2Deoxyhemoglobin
15 g/100ml (dL)Normal Hb Concentration
1 gm of Hb can bind this much oxygen1.34ml of O2
During exercise, as Pco2, Plasma [H+] and temperature increases, the affinity Hb has for O2 will decreaseRight Shift
A decrease in core body temperature will cause an increase in the affinity of Hb for O2Left Shift
Increase in 2,3 DPG level shifts the curveRight Shift
Decrease in 2,3 DPG level shifts the curveLeft Shift
Hb % - X; Sat % - X ; P50 - XPolycythemia
Hb % - X; Sat % - X ; P50 - XAnemia
Hb % - X; Sat % - X ; P50 - XCarbon Monoxide Poisoning
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Pulmonary Circulation

Question Answer
Shunt that does not lead to hypoxemiaLeft to Right Shunt
Shunt that can lead to hypoxemia without pulmonary involvementRight to Left Shunt
Shunt that can lead to hypoxemia due to pulmonary involvementPathological Pulmonary Shunt
Hypoxia, Pulmonary vascular resistance & Gravity are factors affecting thisPulmonary Blood Flow
Reduced ventilation of the apex of the lung is due to increased of this at the apexIntrapleural Pressure
Place in the lung in which the alveoli are already partially expanded due to increased intrapleural pressureApex
If V/Q < 0.8, ↑PaCO2, ↓PaO2, ↓pHHypoventilation
If V/Q > 0.8, ↓PaCO2, ↑PaO2, ↑pHHyperventilation
Ventilation is Zero. Perfusion is normal, V/Q = ZeroAirway Obstruction
Blood flow to the lungs is completely blocked. Blood flow to lungs is Zero. Ventilation is normal. V/Q is InfinitePulmonary Embolism
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