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127 Cards in this Set
- Front
- Back
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Air moves in and out of the lungs as a result of:
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changes in air pressure in the lungs
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Air in the lungs is termed:
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intra-alveolar or intrapulmonic air
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another word for inhale
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inspire
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you inhale when
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pressurein lungs is below atmosphereic pressure (negative)
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what pressure causes inhalation?
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-3mm pressure
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what causes you to exhale
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pressure in the lungs is above atmospheric pressure
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what pressure causes you to exhale?
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+3mm pressure
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what is another word for exhale?
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expire
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What does boyles law state?
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that the pressure of a gas in inversely proportional to its volume
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what happens during inhalation?
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an increasein lung volume causes a decrease in intrapulmonic pressure
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what happens during exhalation?
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a decrease in lung volume causes an increase in intrapulmonic pressure
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changes in lung volume result from
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preceding changes in thoracic volume and pressure
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compliance:
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the lungs are distensible, and can expand when stretched
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pulmonary fibrosis
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occurs when lung tissue is infiltrated by connective tissue. Lung compliance decreases
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emphysema
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occurs when lung tissue is destroyed by agents, such as cigarette smoke. lungs are more distensible and have a higher compliance.
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elasticity
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the lungs contain elactic proteins which allow them to recoil and force air out of the lungs during exhalation.
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Pneumothorax
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is a collapsed lung, occurs when intrapleural pressure rises to equal atmospheric pressure
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pneumothorax may result from:
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a puncture wound of the thoracic wall, rupture of the lung, or thoracic surgery.
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emphysema reduces what?
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the elasticity of the lung
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when elasticity is reduced it makes what difficult?
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exhalation
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surface tension in the lungs is due to?
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a thin layer of water which lines the alveoli
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surface tension is:
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a force which tends to collaps the lungs.
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water is necessary for what in the lungs?
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provide a moist membrane for gas exchange
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what is the surfactant?
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dipalmitoyl lecithin
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what is the surfactant necessary for?
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to reduce surface tension in the lungs to prevent them from collapsing.
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surfactant is secreted by:
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type 2 alveolar cells.
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when does surfactant begin secreting?
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the eighth month of fetal life.
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what is another name for respiratory distress syndrome?
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hyaline membrane disease
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who does respiratory distress syndrome occur in?
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premature babies.
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respiratory distress syndrome or hyaline membrane disease is due to?
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a lack of surfactant
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what happens when a babies lungs are collapsed?
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they are kept alive on a mechanical ventilator until surfactant is produced.
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what do they use now for babies with collapsed lungs?
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cow surfactant given by tracheal tube.
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whats another name for intraplural space?
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intrathoracic space.
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intrapleural (intrathoracic)space must always have:
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a negative pressure, even during exhalation
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the negative pressure in the intraplueral (intrathoracic) space is caused by:
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the elasticity of the lungs, and the surface tension in the alveoli which tend to pull the lungs away from the thoracic wall.
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5 steps of inhalation
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1. contraction of diaphragm and external intercoastal muscles.
2. increse in thoracic volume 3. decrease in thoracic pressure 4. increase in lung volume 5. air flow into lungs |
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contraction of the diaphragm and external intercostal muscles causes:
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increase in volume of thoracic cavity
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increase in thoracic volume causes:
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a decrease in thoracic pressure
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a decrease in thoracic pressure allows
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the lung to expand and increase it volume
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an increse in lung volume causes:
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a decrease in lung pressure (intrapulmonic) below atomospheric pressure (-3mm of Hg pressure)
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a forced inhalation uses:
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additional rib muslces and neck muscles to pull the rib cage up adn out more.
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exhalation is a ____________, resulting from ....
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passive process..... relaxation of the diaphragm and external intercostal muscles.
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relaxation of diaphragn and external intercostal muscles casues:
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a decrease in the volume of the itnrathoracic (intrapleural) space.
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a decrease in volume in the intrathroacic spaces causes
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an increase in intrathoracic pressure
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increase pressure on the lungs and elatic recoil of the lungs reduces
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lung pressure
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a decrease in lug volume causes
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an incrase in lung presure (intrapulmonary) above atmospheric pressure (+3mm pressure)
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contraction of abdominal muscles and internal intercostal muscles casues
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a forced exhalation
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5 steps of exhalation
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1. relaxation of diaphragm and external intercostal muscles
2. decrease in volume in the intrthoracic space 3. increased pressure on the lungs and elastic recoil of lungs 4. decrese in lung volume 5. air flows out. |
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what is atmospheric pressure
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presure exerted by gasses in atmosphereic air.
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at sea level, atmospheric pressure equals:
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760mm of Hg pressure or 760 torr.
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Daltons law states:
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the total pressure of a gas mixture is equal to the sum of the partial pressure of its constituent gases.
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what percent of atmospheric air is oxygen?
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21
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oxygen exerts a partial pressure of ____ at sea level?
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159.6mm of Hg pressure
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Blood flowing through the lungs equilibrates with ......
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alveolar air
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alveolar air has a pp of ?
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105
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at a pp of 105, there is a ______ of disolved oxygen per _______
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.3mls, dl
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at a pp of 105, there is a _____ of oxygen combined with _________ per ____ of blood
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19.7mls, hemoglobin, dl
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Venous blood is low in ... and high in...
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low in oxygen and high in carbon dioxide
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arterial blood is high in ... and low in..
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high in oxygen and low in carbon dioxide
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alveolar air has a pp of _____ and a pC02 of _______
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105, 40
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venous blood has a pp of ____, and a PCO2 of ______
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40, and 46
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as venous blood flows through alveolus....
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oxygen diffuses into the blood and CO2 diffuses into the alveolus
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when venous blood becomes arterial blood.....
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02 is raised from a PO2 of 40 to 100,a CO2 is lowered from 46 to 40
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When venous blood becomes arterial blood, arterial blood then has a Pp of ____ and a PC02 of ______
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100, 40
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body tissues have a PC02of ____ and a PO2 that may vary b/w ___ and ___.
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46; 20 and 40.
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as arterial blood flow through body tissues:
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C02 diffuses into the blood and oxygen diffuses into the body tissues
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when arterial blood becomes venous blood:
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02 is lowered from 100 to 40 and CO2 is rised from 40 to 46
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the rhythimicity center is located:
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in the medulla
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the ____________ fires the stimulate the muscls of the inhalation
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I neurons
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the _________ inhibits the __________ during inhalation
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I neurons; E neurons
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the _____________ fires to inhibit the ____________ and bring on exhalation
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E neurons; I neurons
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the apneustic center is located:
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in the pons region of the brain.
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the apneustic center enhances:
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inhalations by stimulating the I neurons
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the pneumotaxic center is located
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in the pons
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the pneumotaxic center enhances
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exhalations and makes breathing movements regular and smooth
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chemoreceptors, in the ___________, do what?
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in the medulla, respond directly to the CO2 levels in the blood.
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CO2 affects ___ content of _________. Which affects the ___________.
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H+ content of cerebrospinal fluid. Which affects the medulla
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H+ cannot:
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cross the blood brain barrier.
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High levels of CO2 do what:
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lower pH.
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low levels of CO2 do what
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raise pH
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what are carotid and aortic bodies?
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chemoreceptors which monitor the levels of CO2 and H+ in the blood
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Changes in CO2 and pH are the most:
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potent regulators of the rate and depth of breathing.
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A maximum increase in CO2 will:
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increase the breathing rate ten fold
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a maximum decrease in pH (to 7.1) will:
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increase breathing rate 5 fold
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decreased CO2 and elevated pH does wht
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decreases ventilation
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the carotid body:
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moniters the oxygen level of the blood
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oxygen levels have only a minor effect on ______________.
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ventilation
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even though oxygen levels have a minor effect on ventilation, it can be important...
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under severe oxygen deprivation.
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High oxygen levels will reduce:
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ventilation
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low oxgyen levels can only :
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increase ventilation 1.6 fold
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Sids is also known as:
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sleep apnea or crib death
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sids is due to
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cessation of breathing during sleep
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what is the recent evidence of sids:
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that a defct in the respiratory center or the carotid bodies maybe be responsible for some sids deaths.
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irritation reflex causes:
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constriction of bronchioles in response to smoke, smog or other noxious chemicals.
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irritation reflex may also inhibit:
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inhalation to prevent taking moke smog or other noxious chemicals into the lungs.
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hering-breuer reflex is very important in:
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the newborn, but is nto activei nt he adult until the lungs are greatly expanded (exersise)
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hering breurer reflex is initiated by:
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stretch receptors in the lungs
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hering breuer reflex prevents:
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over inflation of the lungs and brings on exhalation.
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carboxyhemoglobin is :
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hemoglobin combined with carbon monoxide.
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Hemoglobin combines with CO ____ times more readily than it does with _______.
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210; oxygen
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____________ percent of CO in air causes dizziness and disorientation.
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one tenth
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at one tenth percent of CO in air, _____ % of Hb is conbined with CO.
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50%
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__________ percent of CO in air is lethal.
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two tenths.
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In hemoglobin loading and unloading of oxygen, the oxygen combing with the hemoglobin is the ______________.
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loading reaction
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in hemoglobin loading and unloading of oxygen, the oxygen dissacociating from hemoglobin is the _______________.
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unloading reaction
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Loading and unloading of oxygen are mainly determined by:
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the P02 of the environment to which hemoglobin is exposed.
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high PO2 in the lungs causes:
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loading
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Low po2 in the body tissues causes:
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unloading
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at pp of 100 in arterial blood, ______ percent of hemoglobin molecules are ......
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97; saturated with oxygen
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at rest, body tissues have a po2 of about
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40mm of Hg pressure.
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at a pp of 40, Hb unloads about ___ percent of its _______________.
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22; oxygen to body tissues.
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during strenuous exercise, body tissues...
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use oxygen rapidly
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during strenuous exercise, body tissues have pp of bout
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20mm hg pressure.
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at a po2 of 20, hemoglobin unloads about ___ percent of __________....
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70% of oxygen in to body tissues.
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the oxyhemoglobin dissocociation curve is a ...
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graphic representation of the pecent satureation of hemoglobin at different PO2 values.
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the oxyhemoglobin diss curve is ______ shaped or ____________.
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S-shaped or sigmoid
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at PO2 b/w 40 and 100, little ...
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oxgyen is unloaded.
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at pp below 40, ...
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oxygen is unloaded rapidly
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Ten percent of CO2 is transported by ....
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being dissolved in plamsa
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twenty percent of CO2 is tranported bye
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attaching to amino groups of Hb molecules.
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carbaminohemoglobin:
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when co2 is transported it attaches to amino groups of hemoglobin that are termed this.
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seventy percent of CO2 is transported
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as bicarbonate in plasma
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carbonic anhydrase:
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enzyme that catalyzes reaction in the RBC, where co2 (high) + H2o will yield H2CO3. This occurs as RBC passes throuch body tissues.
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What happens as RBC passes through body tissues:
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1. Co2 plus h2o yeild h2co3 catalyzed by carbonic anhydrase
2. h2co3 dissociates to for h+ adn hco3-. hco3 diffuses into plasma 3. h+ is buffered by combining with deoxyhomoglobin 4. bicarbonate moves into plasma, chloride ions move into rbc to balance charge. (chloride shift mechanism) |
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What is chloride shift mechanism?
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as bicarbonate moves into plasma, chloride ions move into the rbc to balance the charges.
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The following reactions occur as an RBC passes through the lungs.
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1. h+ + hco3- will form h2co3 in the rbc
2. h2co3 will dissociate to form h20 and c02(low). catalyzed by carbonic anhydrase. 3. as bicarbonate moves into the rbc, chloride comes out of the rbc. (reverse chloride shift mechanism.) |
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what isthe reverse chloride shift mechanism?
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as bicarbonate moves int othe rbc, chloride comes out of the rbc.
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