Lecture 11 Flashcards
Respiratory airflow is governed by the same principles of flow, pressure, and resistance as ________ flow
blood
The flow of a fluid is ___________ proportional to the pressure difference between two points (_______ law: I=V/R)
directly; Ohm’s
The flow of fluid is __________ proportional to the resistance
inversely
___________ pressure drives respiration
- the weight of the air above us
- ________ cm H2O at sea level, or ___ atm
- this number is ________ at higher elevations
Atmospheric
- 760; 1
- lower
____________ law: the pressure of a gas increases as its volume decreases, assuming constant mass and temperature
- as volume increases, pressure __________
- as volume decreases, pressure _________
Boyle’s
- decreases
- increases
______________ pressure is slightly _______ (relative to atmospheric and pulmonary P) that exists between the two _______ layers
- _______ cm H2O
this is because…..
- _______ causes lungs and chest wall to pull in _______ directions
- all at ________________
Intrapleural; negative; pleural
- (-5)
- recoil; opposite
- END of EXPIRATION
During Inspiration….
- intrapleural pressure becomes more __________ (______ cm H2O)
- pulmonary pressure goes from ____ mmHg to _____ cm H2O
- negative; (-8)
- 0; (-1)
_____________: volume of a gas is __________ proportional to its absolute temperature
- affects expansion of lungs
- on a cold day, 60 °F, air will ________ its temperature by 39 °F during inspiration
- inhaled air is warmed to 98.6 °F by the time it reaches the _________
- inhaled volume of 500 mL will EXPAND to _____ mL and this thermal expansion will contribute to the inflation of the lungs
Charles’s law; directly
- increase
- alveoli
- 536 mL
Inspiration….
- In quite breathing, the dimensions of the thoracic cage increase only a few millimeters in each direction
- enough to increase its total volume by ______ mL
- Thus, ____ mL of air flows into the respiratory tract
- When the lungs inflate, the volume of individual ______ increase–> this is where the air goes!
- 500
- 500
- alveoli
The Respiratory Cycle
1. At rest, atmospheric and intrapulmonary pressures are ______ (_______ cm H2O), and there is _____ air flow
2. In inspiration, the thoracic cavity _______ laterally, vertically, anteriorly (volume ________). Intrapulmonary pressure _________ ( ______ cm H2O) below atmospheric pressure, and air flows ____ to lungs
3. In expiration, the thoracic cavity _______ in all three direction (volume _________). Intrapulmonary pressure __________ (_____ cm H2O) above atmosphere pressure, and air flows ______ of the lungs
- equal; NO
- expand (increases); decreases (-1 mmHg); IN
- contracts (decreases); increases (1+ mmHg); OUT
Expiration:
Relaxed breathing
- _________ process achieved mainly by elastic ______ of thoracic cage
- Volume of thoracic cavity _________
- Intrapulmonary pressure ________ (_____ cm H2O)
- _______ than atmospheric pressure so air flows down the pressure gradient and out of the lungs
Forced breathing
- _________ muscles raise intrapulmonary pressure as high as ______ cm H2O; ______ pressure gradient= _________ flow of air out of the lungs
- passive; recoil
- decrease
- increase (+1)
- greater
- accessory; +40; steeper; increase
Resistance to Airflow
- flow of air is ___________ proportional to the resistance
- __________ resistance –> _________ airflow
- Two factors influence airway resistance
1.
2.
- inversely
- increased; decreased
1. Bronchiole diameter
2. Pulmonary compliance
Bronchodilation (_______ in diameter)
- __________ and __________ stimulation
- _________ resistance–> ___________ airflow
increase
- epinephrine; sympathetic
- decrease; increase
Bronchoconstriction (________ in diameter)
- _________, ____________ nerves, _____ air, and ____________
- _________ resistance–> _________ airflow
- suffocation can occur from EXTREME bronchoconstriction brought about by ___________ and ________
decrease
- histamine; parasympathetic; cold; chemical irritants
- increase; decrease
- anaphylactic shock; asthma
Pulmonary compliance: ease with which the lungs can _________
- Compliance is ______ by degenerative lung disease in which the lungs are stiffened by _____ _____= _________ resistance
- Compliance is _________ by the surface tension of the water film inside alveoli
-__________ secreted by great cells of alveoli disrupt ________ bonds between water molecules and thus reduces the surface tension= _________ compliance—> __________ resistance
- ______________________: premature babies lacking surfactant are treated with artificial surfactant until they can make their own
expand
- reduced; scar tissue; increase
- limited
-surfactant; hydrogen; increases; decreases
- Infant respiratory distress syndrome (IRDS)
Only air that enters alveoli, alveolar ducts, etc. is available for ___________
- not all inhaled air gets alveoli, some air occupies:
1. _______________
- _____ mL fills the conducting zone of airway were there is no __________
- can be altered somewhat by _________ dilation of ___________
-increases dead space but allows for ______ flow
- ______________
- in pulmonary disease, some alveoli ______ to exchange gases
- ____________ + _________________
- smoking, cancer, emphysema= _______ alveoli, ________ physiological dead space
gas exchange
- Anatomical dead space
- 150; gas exchange
- sympathetic; bronchioles
-greater - Physiologic (total) dead space
- unable
- anatomical dead space + pathological alveolar dead space
- decreases; increases
If a person inhales _____ mL of air, and _____ mL stays in anatomical dead space, than _______ mL reaches alveoli
- Alveolar ventilation rate (AVR):
____________ * ___________
(____ mL * ______ bpm)= __________ mL/min
- this measurement is crucially relevant to the body’s ability to get _______ to the tissues and dispose of _____________
500; 150; 350
- air that ventilates alveoli * respiratory rate
- (350 mL * 12 bpm)= 4,200 mL/min
- oxygen; carbon dioxide
____________ the measurement of pulmonary ventilation
spirometry
Respiratory Volumes and typical values
- ________________: the amount of air inhaled and exhaled in one cycle during quiet breathing (____ mL)
- ________________: amount of air in excess of tidal volume that can be inhaled with maximum effort (______ mL)
- __________________: amount of air in excess of tidal volume that can be exhaled with maximum effort (______ mL)
- __________________: amount of air remaining in the lungs after maximum expiration; never can be exhaled voluntarily (_______ mL)
- tidal volume (500 mL)
- inspiratory volume (3,000 mL)
- expiratory volume (1,200 mL)
- residual volume (1,300 mL)
Respiratory Capacities
- ___________: amount of air that can be inhaled & exhaled with maximum effort; the deepest possible
(______= ______ +______ + _______)
- ____________: maximum amount of air that can be inhaled after normal tidal expiration
(_____= _______ + ________) - _____________: amount of air remaining in the lungs after a normal tidal expiration
(______= _______ + _______) - _______________: maximum amount of air the lungs can contain
(___________= ______ + ______)
- vital capacity (VC= IRV+TV+ERV)
- inspiratory capacity (IC= TV+IRV)
- functional residual capacity (FRC= ERV+RV)
- total lung capacity (TLC= VC+RV)
_________________: % of vital capacity that can be exhaled in a given time interval
- healthy adult reading is ____% to ___% in 1 second
forced expiratory volume (FVE1.0)
- 75% to 85%
_________: maximum speed of expiration; blowing into a handheld meter
peak flow
_____________ (_______)
- amount of air inhaled per minute
- _____ * __________ (at rest _____ mL * _______ = _____ mL/min)
minute respiratory volume
- TV * respiratory rate (500mL * 12= 6,000 mL/min)
_____________ (_____)
- ______ during heavy exercise
- may be as high as _____ to ____L/min
maximum voluntary ventilation (MVV)
- MRV
- 125; 170 L/min
Spirometry aids in the diagnosis and assessment of _____________ and ___________ lung disorders
restrictive; obstructive
Obstructive disorders: (airway diameter _________ due to inflammation and smooth muscle contractions, or bronchiolar secretion)
- difficult to move air ____ or ____ rapidly. Any diseases that ________ air flow
- greatly _______ _______
Examples:
- __________
- __________
- __________
decreased
- in; out; reduces
- reduced FEV1.0
- bronchitis
- emphysema
- asthma
Restrictive disorders: _________ ability to move air rapidly in and out of lungs, _________ in gas exchange
- characterized by a __________ in pulmonary compliance
- spirometry measurement: usually _______ ______
Examples
- _______________
- ______________
normal; decreased
- reduction
- reduced TLC
- edema-pneumonia
- pulmonary edema
Composition of Air
- _____% nitrogen
- _____% oxygen
- ______% carbon dioxide
- ____- ____% water vapor, depending on temperature and humidity
- _____ gases argon, neon, helium, methane, and ozone
- 78.6%
- 20.9%
- 0.04 %
- 0%-4%
- minor
_______________: total atmospheric pressure is the sum of the contributions of the individual gases
Dalton’s law
____________: the separate contribution of each gas in a mixture
- At sea level, ____ atm of pressure= _______ mmHg
partial pressure
- 1; 760
Composition of inspired (atmospheric) air and alveolar air differs because of 3 influences
1. Air is _________ by contact with mucous membranes
- alveolar PH2O more than ____x higher than inhaled air
- Alveolar air ______ with _________ air
- oxygen gets diluted and air is enriched with CO2 - Alveolar air __________ O2 and CO2 with blood
- PO2 of alveolar air is about ____% that of inspired air
- PCO2 is more than ______ times higher
- humidified
- 10 - mixes; residual
- exchanges
- 65%
- 130
Alveolar Gas Exchange
- the “swapping” of O2 and CO2 across the _____________ ____________
- air in the alveolus is in contact with a film of _______ covering the alveolar epithelium
- for oxygen to get into the blood, it must ______ in this _____ and pass through the __________ _________ which separating the air from the bloodstream
- for carbon dioxide to leave the blood it must pass the other way and then diffuse out of the______ film into alveolar air
- respiratory membrane
- water
- dissolve; water; respiratory membrane
- water
_______________: at the air-water interface, for given temperature, the amount of gas that dissolves in the water is determined by its __________ in water and its _______ _______ in air
- The _________ the PO2 in the alveolar air, the ______ O2 the blood picks up
- Since blood arriving at an alveolus has ______ PCO2 than air, it _______ CO2 into the air (that is, into the _______)
Henry’s law; solubility; partial pressure
- greater; more
- higher; releases; alveoli
Alveolar Gas Exchange: Pressure Gradient of the Gases
- Normally:
- PO2= _____ mmHg in alveolar air versus _____ mmHg in blood
- PCO2= _____ mmHg in blood versus ______ Hg in alveolar air (gradient isn’t big but CO2 can ______ better in water)
- 104; 40
- 46; 40 (dissolve)
Oxygen Loading in Relation Partial Pressure Gradient
- At high altitudes, the partial pressures of all gases are __________
-_______ gradient, so ________ oxygen diffuses into the blood - Hyperbaric oxygen therapy
-treatment with oxygen at >1atm of pressure
-_________ gradient, so ________ oxygen diffuses into the blood
- lower
-less; less - steeper; more
Changes in PO2 and PCO2 vary along the Circulatory Route
- PO2= ______ mmHg in arriving blood versus ______ mmHg in tissue
- PCO2= _____ mmHg in tissue versus _____ mmHg in arriving blood
- 95; 40
- 46; 40
Solubility of the gases
- CO2 is ____ times as soluble as O2
-_____ amounts of O2 and CO2 are exchanged across the respiratory membrane because CO2 is much more _______ and ______ more rapidly
Membrane Surface Area
- ____ mL blood in alveolar capillaries, spread thinly over ___ m^2
- 20; equal
-equal; soluble; diffuses - 100; 70
Alveolar Gas Exchange: Other factors that affect efficiency
____________ ______________
- Normal: only ____ um thick and presents little obstacle to diffusion
- Pathological: when membrane is ______, gases have farther to travel between blood and air and cannot equilibrate fast enough to keep up with blood flow
-_________________ in _____________ failure causes edema and thickening of the respiratory membrane
-______________ causes thickening of respiratory membrane
Membrane thickness
- .5
- THICKER
-pulmonary edema; left ventricular
-pneumonia
_____________: perfusion adjusted to changes in ventilation
Ventilation-perfusion coupling
Response to reduced ventilation
- _________ air flow
- ___________ PO2 in blood vessels
- _______________ of pulmonary vessels
- _______________ blood flow
- result: ________ matches _________
Response to increased ventilation
- __________ air flow
- __________ PO2 in blood vessels
- ____________ of pulmonary vessels
- ____________ blood flow
- result: ________ matches ________
- decreased
- reduced
- vasoconstriction
- decreased
- blood flow; airflow
- increased
- elevated
- vasodilation
- increased
- blood flow; airflow
Response to reduced perfusion
- _________ blood flow
- _________ PCO2 in alveoli
- _________ of bronchioles
- __________ airflow
Response to increased perfusion
- __________ blood flow
- __________ PCO2 in alveoli
- ___________ of bronchioles
- ____________ airflow
RESULTS: airflow matches blood flow
- decreased
- reduced
- construction
- decreased
- increased
- elevated
- dilation
- increased
