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104 Cards in this Set
- Front
- Back
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_____ is where oral and nasal cavity meet. It functions in ______ breathing.
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pharynx
mouth breathing |
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pleurisy
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infection of pleural cavity. often sign of additional pathology.
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during normal breathing, inspiration is active or passive? how about expiration?
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inspiration: passive
expiration: passive you are not aware that you are breathing |
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what process maintains the negative pressure within the pleural cavity?
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draining of pleural fluid by the lymphatics
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Boyle's Law
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C = P * V
P = pressure V = volume C = constant mass @ constant pressure |
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Air entering lungs is explained by what law?
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Boyle's Law, air rushes in to equalize pressure
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muscles used during heavy breathing:
muscles of inspiration muscles of expiration |
muscles of inspiration: external intercostals, SCM, scalleni, anterior seratus
muscles of expiration: abdominal recti, internal intercostals |
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function of
1. external intercostal 2. scalleni 3. anterior seratus |
1. raise rib cage
2. lifts 1st 2 ribs 3. lifts other ribs |
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rib cage change during inspiration
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thoracic rib cage moves upward and outward
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at max lung vol, is pleural pressure highest or lowest?
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lowest
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At rest alveolar pressure =
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atmospheric pressure
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alveolar pressure is
+ or - during inspiration + or - during exhalation |
inspiration: negative during inspiration
exhalation: positive during exhalation |
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define transpulmonary pressure
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pleural pressure - alveolar pressure
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compliance of lungs is associated with 2 facors
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1. elastic forces of lung itself: collagen and elastin
2. surface tension |
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name for pulmonary surfactant
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DPPC - dipalmitoylphosphatidylcholine
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surfactant is secreted by and released in
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type II cells, released in lamellar body of the cells
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surfactant is first produced during what stage of development?
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3rd trimester, before birth
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define tidal vol, numerical value of tidal volume
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normal breathing
0.5L |
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inspiratory reserve volume (IRV). define and numerical value
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inspire with full force
3L |
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expiratory reserve volume (ERV). define and numerical value
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expire with full force
1.1L |
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inspirational capacity (IC) equals
represents? |
IC = V + IRV
max inspiration |
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functional residual capacity (FRC) equals and represents?
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FRC = ERV + RV
air in lungs after normal expiration |
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vital capacity (VC) equals and represents?
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VC = IRV + V + ERV
inhale max then exhale max |
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total lung capacity (TLC) equals (2 equations)
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TLC = VC + RV
TLC = IC + FRC |
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pulmonary volumes (V, IRV, ERV and RV) in women are lesser than men by what percentage?
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25%
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respiratory structures in the lungs iinclude
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terminal bronchioles, alveolar sacs, alveoli
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process of normal inspiration
process of normal expiration |
inspiration: diaphragm contracts -> lungs vol increase -> atmospheric pressure forces air into the increased space of the lungs.
expiration: elastic recoil of lungs and chest wall -> air leaves |
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function of surfactant
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detergent-like phospholipid that breaks up H-bonding, thus surface tension
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anatomical dead space. examples where it's located.
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anywhere that air enters passage but not available for gas exchange.
trachea and large bronchi |
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compliance work is required to
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to expand the chest against the lung and chest elastic forces
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compliance work, tissue resistance work and airway resistance work are greatest during?
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inspiration
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tissue resistance work is required to
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overcome viscosity of lung & chest wall structures
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under what condition is expiratory work greater than inspiratory work?
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during exercise and diseased condition
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what kind of breathing pattern is efficient and will create less dead space.
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deep breaths
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Is dead space expired first during expiration?
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yes.
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2 types of dead space
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anatomical dead space
alveolar dead space |
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define alveolar dead space
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air is in the alveolar, but not taken up during blood exchange.
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increased pulmonary vol create ____ pressure, which pulls air into alveoli
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negative
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blood pass thru pulmonary capillaries ____ sec normally, ____ sec with increased cardiac output
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0.8sec
0.3sec |
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physical properties of pulmonary arteries compared to systemic arteries
width? vessel wall thickness compliant? |
pulmonary arteries are wider, thinner walled and more compliant than systemic arteries
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systole: pulmonary artery pressure ___
R ventricular pressure diastole: pulmonary artery pressure ___ R ventricular pressure |
=
< |
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numerical measure of systolic and diastolic pulmonary pressure
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S: 25
D:8 |
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in pulmonary capillaries the pressure is ____ mmHg. This number is more or less than peripheral capillaries?
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7 mmHg
less |
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pulmonary vessel adjust to increasing pressure (think of more O2) by ____ and to decreasing pressure (think of less O2) by _____.
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enlarging
contracting |
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stretching of alveoli releases what gas? the function of the gas?
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NO
dilates pulmonary arteries |
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Below what percent of O2 level in alveoli will cause constriction of vessels. This phenomenon is called what?
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70% of normal O2 in alveoli
hypoxic lung vasoconstriction |
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in systemic vessel, low oxygen dilates or constrict vessels, in order to increase blood flow?
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dilates vessels
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standing upright will result in ________ in pulmonary arterial pressure. Meaning there will be more blood at the bottom of the lungs than top.
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gradient
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2 factors contribute to gradient in pulmonary arterial pressure in a vertical lung
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gravity and hydrostatic forces
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blood only flows when pulmonary capillary pressure is (>, =, <) than alveolar pressure
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>
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Palv, Pa, Pv
Zone 1 Zone 2 Zone 3 |
Zone 1: Palv > Pa > Pv
Zone 2: Pa > Palv > Pv Zone 3: Pa > Pv > Palv |
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Blood flow in
Zone 1 Zone 2 Zone 3 |
1: no blood flow
2: blood flows intermittent 3: blood flows continuously |
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Healthy people don't have what zone? but under what condition the zone is present.
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Zone 1
occurs if arterial pressure drops, ex: after blood loss |
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In Zone 2, alveolar pressure (>, =, <) than diastolic but (>, =, <) than systolic pulmonary blood pressure.
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alveolar pressure > diastolic pulmonary blood pressure
alveolar pressure < systolic pressure |
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blood flow to lungs increased how much with heavy exercise
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7x
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blood flow to lungs increases with heavy exercise because 2 reasons
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1) increasing # of open capillaries
2) increasing diameter to double rate of flow thru capillaries |
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during exercise, how much does pulmonary blood pressure goes up? why?
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slight increase in pulmonary blood pressure
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modest increase in pulmonary blood pressure during exercise is beneficial b/c 2 reasons.
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1. less strain on heart
2. prevents edema in lungs |
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If left atrium pressure need to increase above 30mmHg, what will happen to pulmonary capillary pressure, and change of pulmonary capillary pressure will lead to what?
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pulmonary capillary pressure increase will lead to pulmonary edema
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slight increase of pulmonary blood pressure during exercise will convert zone ___ to zone ___ in lungs.
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zone 2 to zone 3. systolic pulmonary blood pressure frequency increases, blood flow more frequently.
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pulmonary edema, how it occurs (2)
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1. increase in left atrial pressure
2. damage to capillary membranes (e.g. pneumonia, poison gas) leads to increased interstitial osmotic pressure |
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pulmonary arterial hypertension
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constriction of pulmonary blood vessel (less O2 circulation), to compensate, R heart works harder, eventually swells.
happens more often in women (rare disease) |
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treating pulmonary arterial hypertension with what drug?
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Viagra
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How does Viagra treat pulmonary arterial hypertension?
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it inhibits degradation of cGMP by PDE5 (phosphodiesterase 5). cGMP eventually leads to vascular smooth muscle relaxation and then pulmonary dilation.
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respiratory center located at
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medulla oblongata and pons
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dorsal respiratory group
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1. controls inspiration
2. controls endogenous beating rhythm, even the innervation of DRG is severed. the pacemaker activity drives tidal breathing. 3. tidal breathing (AP frequency) starts up slowly for about 2 sec, then diaphragm contraction stops for 3sec as lung tissue return to its original state 4. CI IX and X deliver inputs from peripheral chemoreceptors and baroreceptors to DRG. |
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ventral respiratory group
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1. control inspiration and expiration
2. inactive during quite breathing 3. when increased ventilation is signaled, VRG is activated to increase breathing. 4. mainly for expiration 5. used as overdrive (cruising) mechanism during exercise 6. located in nucleus ambiguus, nucleus retroambiguus |
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pneumotaxic center
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1. controls rate and depth of breathing by turning off inspiration ramps (inhibiting DRG reduce duration and depth of inspiration) and increasing shallow breaths frequencies
2. is located in nucleus parabranchialis, pons |
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apneustic center
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blocks the switching off of the dorsal respiratory group
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medulla oblongata and pons include these respiratory centers and groups
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dorsal respiratory group
ventral respiratory group pneumotaxic center apneustic center |
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mechanism of Hering-Breuer inflation reflex
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breathing activated the stretch receptors, which sends a inhibitory signal via vagus nerve to dorsal respiratory group (inspiration inhibition). DRG then sends signal to phrenic nerve, which decreases the diaphragm contraction.
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when is Hering-Breuer inflation reflex activated?
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activated if tidal volume is 3x normal one
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Increased CO2, via H+ trigger ______ to increase respiration
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central chemosensitive area in ventral medulla
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steps that increased blood [CO2] trigger central chemosensitive area
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1. CO2 cross the BBB
2. converted to carbonic anhydride by carbonic acid 3. carbonic acid dissociate to H+ and HCO3- 4. H+ binds to receptors in chemosensitive area 5. send signals to DRG to increase ventilation rate |
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decreased O2 activates ________ to increase respiration
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peripheral chemoreceptors in carotid bodies
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How does O2 signal peripheral chemoreceptors
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If O2 pressure drops below 60mmHg, stimulation of O2 sensors sends signals via CN IX to DRG. O2 sensors are less sensitive than CO2 sensor, it serves as a second level of control.
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affect of anesthesia on respiratory center. examples of anesthetics are ...
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reduce ventilation
morphine, sodium pentobarbitol |
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what provides energy for movement during diffusion of gases
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kinetic motion of molecules
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Dalton's Law of partial pressure
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Pt = Pa + Pb + Pc .... Pn
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Pressure is equal to
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P = F/A
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in a mixture of gases, each gases tends to diffuse independently of all the other gases
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T
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gas diffuse at a rate proportional to its
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partial pressure gradient
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Henry's Law
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Partial pressure = concentration of dissolved gas / solubility coefficient
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CO2 is ____ times more soluble than O2, since it's stable in H2O
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20x
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For CO2 diffusion, solubility coefficient is much larger than differences of partial pressure
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Diffuse quickly
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Henry's Law states that concentration of gas in fluid is proportional to amount of gas in air above fluid
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T
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normal healthy individual: V./Q =
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1
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ventilation-perfusion:
Air no blood is called; V/Q = Blood no air is called; V/Q = |
profusion is blocked: dead space; V/Q approaches infinity (V/Q > 1)
ventilation is blocked: shunt; V/Q approaches 0 (V/Q < 1) |
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At apex of the lungs, is it physiological dead space or shunt. How about at the base of the lungs.
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apex: dead space, since blood pressure < alveolar pressure (no blood flow)
base: shunting, since blood pressure > alveolar pressure (blood flow continuously) |
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blood that supply bronchial vessels are physiological shunt or dead space? Explain.
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small proportional blood that supplies bronchial tissue but are not involved in gas exchange. So there's blood flow but no air flow; hence shunting.
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how many breaths does it take to totally replace all gases in the alveolar space? why so slow?
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16 breaths
alveolar air replaced slowly to stabilized blood gases. buffering capacity prevents large fluctuation in the blood gas concentration. |
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surface tension equation
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Pressure = 2 * surface tension/ radius of alveolus
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cooperative binding of O2 with hemoglobin have what shape of curve?
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sigmoidal curve
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partial pressure of O2:
104mmHg -> 95mmHg -> 40mmHg |
T
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mean tissue O2 partial pressure is
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23 mmHg
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what factors shifts the hemoglobin dissociation curve to the right? (4)
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1) increased H+
2) increased CO2 - Bohr effect 3) increased temperature 4) increased BPG |
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function of BPG
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enhance O2 release from hemoglobin
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Bohr Effect:
In lung, pH rises because CO2 ([H+] decreases) leaves blood In tissue increased CO2 ([H+] increases) leads to decrease in pH |
O2 binds to hemoglobin in lungs
O2 released from hemoglobin in tissue |
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Hb saturation
in lungs in tissues |
lungs: 97%
75% |
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3 ways CO2 are transported in blood
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1) 7% remains as gas in blood
2) 23% transported as carbaminohemoglobin 3) 70% transported as bicarbonate (HCO3-) dissolved in blood |
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acetazolaminde
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inhibitor of carbonic anhydrase, raises tissue CO2 pressure by 80%
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Explain chloride shift in CO2 transport
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increase in HCO3= raises cellular pH
cellular pH is maintained by transporting HCO3- to outside in exchange for extracellular Cl- |
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mean RBC [Cl-] is higher or lower in venous blood than arterial blood?
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higher
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Haldane effect
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in lungs, O2 replaces CO2 on Hb
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