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267 Cards in this Set

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What is the purpose of the nasal passages? Whose law applies to this
Filtration (primarily due to turbulence versus hairs actually filtering); humidification (to 100% relative humidity)
What is the partial pressure of water vapor in the nasal passages at STP?
47 torr
What is the effect of humidification by the nasal passages on O2 delivery? Whose law applies here?

Humidification decreases the driving pressure of O2 to the lungs- 100% FiO2 becomes diluted by the 47 torr of water vapor that is contributed by the nasal passages. Dalton's Law of Partial Pressures applies here
How many ribs are there? How many true, fused. amd floating?
12 ribs; 7 true, 3 fused at the sternum. 2 float
The sternal angle (angle of Louis) is the landmark for _____. What is the significance of this?

Landmark for 2nd rib (and 5th thoracic vertebrae)
landmark for carina;
decompress pneumothorax at 2nd intercostal space, midclavicular line (below second rib)
70% of the work of breathing is accomplished by the ___________.
Diaphragm
_______% of the work of breathing is contributed by the diaphragm
70%
What is the function of the external intercostal muscles?
Elevate the ribs and expand the AP diameter of the chest
Diaphragmatic contraction causes________.
Descent- moves down and increases the intrathoracic volume
Descent of the diaphragm causes_________
pressure in the chest to decrease, augments venous return
Spontaneous respiration _______ venous return
Increases/augments
Internal intercostal muscles are used during ______
expiration
The diaphragm separates the ________ from the ______

Thorax from the abdomen
The _______ intercostals are the muscles of inspiration
external
The__________ intercostals are the muscles of expiration
Internal
The diaphragm has ____ major openings. What passes through each of them?
Three openings: aortic, esophageal, and IVC foramen
Aortic: Aorta, thoracic duct, greater sphlanic nerves, and sometimes azygos vein
Esophageal: Esophagus and Vagus nerve
IVC foramen: Inferior Vena Cava, lymphatics, R. phrenic nerve
Movement of the ______ joint increases the AP diameter
Costovertebral joint
Movement of the costovertebral joint increases the ________
AP diameter
The upper ribs are elevated by the __________
Diaphragm
Elevation of the upper ribs causes ______ and _____ movement of the sternum
Elevation and forward movement of the sternum
The diaphragm is innervated by the _____ nerve, which is made up by CN_____
Phrenic nerve, C3, 4, 5
Each phrenic nerve controls _______
innervation to 1/2 of the diaphragm independently; paralysis of 1 phrenic nerve does not effect the other 1/2 of the diaphragm
The diaphragm is under _____ voluntary control
limited
When the diaphragm contracts, intrathoracic volume ______ and intrathoracic pressure ______, according to ______ law.
Volume increases, pressure decreases according to Boyle's Law
The lungs are attached to the _____ and the ______.
Heart and trachea
The lungs are attached to the heart and the trachea by the ______ and the ______.
Pulmonary root and pulmonary ligament
The right lung is _____, _____, and ______ than the left
right heavier, shorter, wider than left
The left upper and lower lobes are divided by the _______.
Oblique Fissure
The Right upper, middle, and lower lobes are divided by the _____ and _______.
Oblique and horizontal fissures
The pulmonary root is made up of _______.
Blood vessels
The pulmonary ligament is made up of ________
An outcropping of the pleura
What is the name of the "little tongue" on the LUL that would embryologically correllate the the middle lobe?
Lingula
What are the borders of the lungs/thoracic cavity at FRC at each of the following landmarks:
1. the midclavicular line
2. mid-axillary line
3. the spine
MCL: xiphoid to 6th rib
Mid-axillary: 8th rib
Spine: T10
During deep inspiration, the lower borders of the lungs descend ________
2 spaces
What is the name of the artery that comes off of the subclavian that is sometimes used in cardiac surgery?
Internal Mammary artery
The internal mammary artery comes off of the ______
Subclavian
The pulmonary ______ carries deoxygenated blood from the RV
Artery
The pulmonary artery carries ________ blood
Deoxygenated
The left PA is attached to the aorta by the _______
Ligamentum arteriosum
How many pulmonary veins are there? How many pulmonary veins enter the heart?
5 pulmonary veins; two joing before entering, so only 4 veins enter heart
The pulmonary veins carry ______ blood from the lungs to the ______
Oxygenated blood from lungs to LA
________ arteries nourish bronchi, bronchioles, connective tissue of the lung, and pleura
Bronchial arteries
Lung tissue is supplied with oxygen and nutrients by _______
the bronchial arteries
The bronchial arteries arise from the _____
Typically from the aorta
Blood from the bronchial arteries is returned via ______
Pulmonary vein
Blood returning from the bronchial arteries via the pulmonary vein contributes to _________
Venous admixture- the reason O2 saturation is never really 100%
How is an anatomic shunt different from a physiologic shunt?
Physiologic shunt is not pathalogic- created by venous admixture in a normal body
Some bronchial veins join with pulmonary arteries, contributing to:
Venous admixture
The respiratory passages begin at the level of the ______ cartilage
Cricoid
What level is the cricoid cartilage? (C_____)
C6
Smooth muscle and glandular innervation of the airways is primarily ______ from the ______ nerve
Parasympathetic; vagus nerve
Pain fibers in the respiratory tract can arise from ________ and are carried by the ________
mucous membranes, carried by vatus
The vagus nerve supplies _______ and ______ within the respiratory tract
Smooth muscle and glands
The trachea is made up of _______ cells to lend _________
Psuedostratified columnar epithelium; lends structure to airways
Chronic irritation of the airways, such as smoking leads to increased _______ cells and decreased _______ cells.
Increased goblet cells (mucous), decreased cilia (decreased ability to get rid of bacteria and debris)
Columnar cells give way to _______ cells at the level of the ________
Cuboidal epithelium at the level of the bronchi
Cuboidal cells are very thin to allow for _____ and ______
Diffusion and distensibility
At the level of the respiratory bronchioles, the cell type changes from ________ to __________.
Cuboidal to squamous cells
At what level do cuboidal cells give way to squamous cells within the respiratory tract?
The level of the respiratory bronchioles
Squamous cells are:
a single layer of very thin cells to allow for easy diffusion and gas exchange
What are the major differences between the right and left mainstem bronchi?
R: shorter (2.5 cm), wider, less acute angle
L: Longer (4.5 cm), narrower, more acute angle
Are the bronchi sensitive to pain?
Relatively insensitive to pain, but sensitive to irritation
Aspiration tends to go to the most ______ area. What is this when supine? When upright?
Most dependent area; when supine, will go to RUL (most dependent area d/t sructure of R. mainstem bronchus); when upright, will go to RLL
Each division of the trachea/bronchi is called a _________
generation
How many generations are there before the alveoli?
20-25
_______ within the airway starts to dissipate with successive generations
Cartilage
Succeeding generations increases the ________ and ________ of the airways
number and cross-sectional area
Flow velocity is _______ to area. Whose law?
inversely proportional; Pouseille's Law
Flow at the level of the respiratory bronchioles is almost exclusively by _______
Diffusion
Why does HFOV work?
Difusion
What is the relative velocity of flow at the level of the alveoli
Very slow, due to large cross sectional area
What are the three primary generations of bronchi?
Main, lobar, segmental
With succeeding generations, ______, ________, ________ all INCREASE
number, cross-sectional area, muscular layer
With successive generations, ______, _______, ___________, _______, ______ all DECREASE
Flow velocity, cartilage, mucous cells, ciliated cells, and goblet cells all decrease
Ciliated cells disappear by the _______ generation. What cell type appears here?
6-7th generation; cuboidal cells also appear here
The functional divisions of the airways are the _______, _______, and _______.
Conductive airways, transitional airways, and respiratory airways
What is the function of the conducting airways? What structures are involved?
Conduct pasage of air; from trachea to respiratory bronchioles
What is the function of the respiratory zone? What structures are involved? How many generations fall into this zone?
Gas exchange; 8 generations; alveolar ducts, alveolar sacs, alveoli
Structures of the conducting zone are _______ lined, and ______ gas exchange occurs here
Mucosa lined; no gas exchange
Structures of the respiratory zone are lined with_________ to allow for ________.
Simple squamous epithelium; gas exchange occurs here
_________ allow for gas exchange from one alveoli to another
Pores of Kohn
What structure accounts for the efficacy of the inspiratory pause technique?
Pores of Kohn; allows time for gas to move through pores to re-inflate atelectatic areas
Alveolar Type 1 cell: what is it and what does it do?
Makes the structure of the alveolar wall; metabolically inactive, cannot replicate
What cell type makes up the alveolar walls?
Type 1 cells
Alveolar Type 2 cells: what are they and what do they do?
Make surfactant and continually secrete it by excocytosis; can turn into type 1 cells
Alveolar Type 3 cells: what are they and what do they do?
Macrophages
What is the total surface area for gas exchange?
70 m2
How many alveoli does the average person have? When does number peak?
300 million; peaks at age 9
The parietal pleura is a serous membrane that lines the ______, ______, and ________.
Mediastinum, diaphragm, and thoracic wall
The lungs extend to the level of C______, which is above the level of the ___________
C7, above the first rib
The superior margin on the lung extending above the level of the first rib is significant for:
Risk of pneumothorax with subclavian line placement or (infraclavicular) brachial plexus block
Inspiratory muslecs (external intercostals) increase the ________ dimension of the chest, while the diaphragm increases __________
External intercostals increase AP diameter, diaphragm increases vertical dimensions
Boyle's law states that:
Pressure and volume have an inverse relationship; if you increase the volume (space) within the thoracic cavity, you decrease the pressure
The intrapulmonary or alveolar pressure is:
about the same as atmospheric pressure
The intapleural pressure is ______ at FRC, because:
about -4 at FRC, because the lungs want to collapse and the ribs want to expand, creating a vacuum within the pleural space
The transpulmonary pressure equals:
Intrapulmonary pressure - intrapleural pressure
__________ results because of increased transpulmonary pressure
Negative pressure pulmonary edema
Intrapleural pressure is always ______
Always negative
Compliance is defined as:
Change in volume/ change in pressure
What is the formula for static effective compliance?
(TV)/(PP-PEEP)
Normal adult lung compliance is about:
200 mm Hg
Lung compliance changes due to what three broad categories:
Disease processes/pathology, lung volumes, and surface tension within the alveoli
Emphysema causes _______ lung compliance; and is reflected by a _______ shift on the compliance curve
Increased compliance: large floppy airways with poor recoil and poor gas exchange (upshift on compliance curve)
Fibrosis causes _______ compliance, and is reflected by a _______ shift on the compliance curve
Decreased compliance (not much volume change despite high pressures); downward shift on compliance curve
Lungs have decreased compliance at ________ and _______ lung volumes
Very low and very high
Surfactant is produced by:
Type II pneumocytes
According to the law of laplace, the pressure required to keep alveoli open is directly proportional to__________, and inversely proportional to ________.
Directly proportional to surface tension, inversely proportional to radius (size)
Whose law describes the idea that if you have higher surface tension within the alveoli, more pressure will be required to keep them inflated?
LaPlace
Airflow resistance is _______ proportional to airway radius, according to ________Law
resistance inversely proportional to radius; Pouseille's Law
According to Pouseille's Law, airway resistance is inversely proportional to ________
the radius to the 4th power
Ohm's Law states that airway resistance =
(Atmospheric pressure- alveolar pressure)/velocity
The primary factor affecting whether flow is laminar or not is:_______
Viscosity
Reynold's number is directly proportional to _______, _______, ________ and inversely proportional to _________
directly proportional to: Velocity, diameter, density; inversely proportional to viscosity
A Reynold's number over _______ indicates turbulent flow
4000; <2000=laminar flow
________ promotes laminar flow, while ________, ________, ________ promote turbulent flow
Viscosity promotes laminar flow, while velocity, increased diameter, and density promote turbulent flow
Heliox is used in cases of increased airway resistance because
It has a lower molecular weight (density) than oxygen and promotes laminar flow
Resistance has a directly proprtional relationship with ______, _______, and _______
length of tube, viscosity, and velocity all increase resistance
Maximal voluntary ventilation is:
The maximal amount of air that can be breathed in a given time (like maximal minute ventilation)
The maximal amount of air that can be breathed in a given time :
Maximal voluntary ventilation
FVC:
Maximal amount of air that can be exhaled following full inhalation
Maximal amount of air that can be exhaled following full inhalation
FVC
FEV1
Maximal amount of air that can be exhaled in the first second (Forced Expiratory Voume 1 second)
If FEV1 and FVC are BOTH low, it is indicitive of:
Restrictive disease
If FEV1/FVC is low, and FVC is normal, it is indicitive of:
Obstructive disease
What is the advantage of the forced mid-expiratory flow rate?
Effort independent
Supine position _______
Reduces FRC
Induction of anesthesia reduces FRC by
an additional 15-20%
What is the effect of muscle relaxants on FRC?
Decreases
Approximately what % of TV is found within the conducting and transitional respiratory zones?
about 33%
How is alveolar ventilation calculated?
Minute ventilation (TV x RR) - dead space ventilation
Are the terms minute ventilation and alveolar ventilation interchangeable?
No; alveolar ventilation accounts for dead space ventilation
Neck extension ________ (increases or decreases) dead space ventilation
Increases (lenghthens conducting zone)
An artificial airway (ETT) ________ (increases or decreases) dead space ventilation
Decreases (due to smaller diameter, so smaller conducting zone)
Positive pressure ventilation ________ (increases or decreases) dead space ventilation
Increases; due to decreased VQ matching
Hypotension ________ (increases or decreases) dead space ventilation
Increases: areas are ventilated but not perfused
Pulmonary embolism increases _________
Increases dead space ventilation; areas are ventilated but not perfused
Dead space (definition)
ventilation which does not contribute to gas exchange (due to lack of perfusion)
ventilation which does not contribute to gas exchange
Dead space
Average Dead space ______ ml/kg or _______ ml
2ml/kg or 150 ml
Anatomic dead space occurs because of the ________ zone
Conducting zone
Alveoloar dead space:
Occurs because alveoli are ventilated but not perfused
Physiologic dead space:
Alveolar + anatomic dead space
VA =
VT-VD
Shunt:
Perfusion but no ventilation (ex. atelectasis)
Peripheral chemoreceptors sense:
Decreased O2, increased CO2, decreased pH
Central Chemoreceptors sense:
Decreased pH, increased CO2
What is the Hering-Breuer Reflex?
Stretch receptors in lungs send signals to brainstem to decrease respiration
The primary respiratory center is located in the:
Medulla
What does the Dorsal Respiratory Group do?
Contains inspiratory neurons that signal the lungs to breathe in (exhalation is passive); modulates the ventral respiratory group
What does the Ventral respiratory Group do?
It is controlled by:
Contains Inspiratory and expiratory neurons which are quiet during normal respiration; active during forced expiration and exercise; controlled by the Dorsal Respiratory Center
The Dorsal respiratory group contans:
Tractus solitarius- CN IX and X
The apneustic center in the _______ signals a characteristic breathing pattern that looks like:
Pons; apneustic breathing = APRV type ventilation; large breathes with intermittent short exhalations (pontine breathing)
What does the pneumotaxic center in the ______ do?
In Pons, Antagoizes the apneustic center, inhibits respiration
J receptors: what are they and what do they do?
Juxtocapillary receptors within the lung respond to noxious stimuli (pulmonary edema, congestion, volatile anesthetics) and trigger an increased respiratory rate (rapid, shallow breathing)
Volatile anesthetics produce the characteristic respiratory pattern by triggering _________ within the ______.
Rapid, shallow breathing by triggering J-receptors within the alveolar interstitium
J- receptors can be _______ or _______ receptors
Stretch or chemoreceptors
What is the afferent nerve that carries signals from the J-receptors in the alveolar interstitium?
Vagus (CNX)
Respiration is triggered by ______ and ______ levels
CO2 and H+ ion levels
Stretch receptors in the lungs carry signals via the ______ nerve to start/stop each respiratory cycle
Vagus
Central chemoreceptors regulate ______ of the response to changes in CO2
80%
________ chemoreceptors regulate 80% of response to changes in CO2
Central
________ chemoreceptors respond to changes in CO2 more rapidly but have less of an overall effect than _________ chemoreceptors which respond more slowly but produce a more significant overall effect
Peripheral chemoreceptors faster, but only account for 20% of response, whereas central chemoreceptors are slower but produce 80% of the effect
Central chemoreceptors are located in the ________
Medulla
Central Chemoreceptors are triggered by ________ (but not _______ and _______)
Central chemoreceptors are only triggered by increased CO2 because it rapidly crosses the BBB whereas H+ and HCO3- are charged and cannot diffuse into the CSF to trigger these receptors
Where are peripheral chemoreceptors located?
Aortic arch and carotid bodies
Baroreceptors are located in the carotid and aortic _______ and chemoreceptors are located in the carotid and aortic_______
Baroreceptors = sinuses
Chemoreceptors = bodies
_______ chemoreceptors are the bodies main response center for hypoxemia
Peripheral
Which chemoreceptors are more sensitive: carotid or aortic?
Carotid
Peripheral chemoreceptors respond to changes in:
CO2, pH, H+, O2
Plasma PO2 less than ______ triggers peripheral chemoreceptors
<60
The threshold CO2 that limits voluntary breath holding is:
CO2 50-70
Capillary beds become very dense distal to ________ in the region of the ___________
pulmonary arterioles in the region of the respiratory bronchioles
Pulmonary ___________ blood flow follows the divisions of the bronchi fairly closely whereas ________ blood flow does not
arterial blood flow follows bronchial divisons, venous return does not
Bronchial arteries branch from the ________
Aorta
Bronchial arteries meet the metabolic needs of:
the airways and pulmonary parenchyma
The bronchial arterteries empty ________ blood into the pulmonary _______ for transport back to the heart
deoxygenated blood into pulmonary veins for return to LA
Average blood volume in the lungs: (ml)
450 ml
Large increases in the pulmonary blood volume (are/are not) well tolerated because of _______
Well tolerated because of compliance of pulmonary arterial system
Pulmonary blood volume increases up to _________ are generally well tolerated
1L
Total blood volume within the lungs generally equals about what % of CO?
9-10%
Pulmonary vasculature generally has (larger or smaller) diameters than corresponding systemic vasculature?
Larger diameters, shorter branches, thinner membranes (Pouseille's law, Fick's Law)
Pulmonary vasculature has less _____ and _____ than systemic arteries
Less smooth muscle and elastin
The biggest regulating factor on pulmonary blood flow:
Local factors (hypoxia)
Which has more control over pulmonary blood flow: local factors or autonomics?
Local factors
Hypoxia within the lungs causes _______ and systemically causes _____.
Pulmonary: hypoxic pulmonary vasoconstriction
Systemic: vasodilation
Hypercapnia and acidosis within the lungs causes _______ and systemically causes ________.
Pulmonary: mild vasoconstriction
Systemic: vasodilation
Hypercapnia causes the bronchioles to:
dilate
Slight changes in pulmonary vascular resistance have _______ effects because
large effects because it is such a low pressure system
Parasympathetic stimulation causes pulmonary vasculature to _______
Vasodilate
Sympathetic alpha stimulation causes pulmonary vasculature to _______
Vasoconstrict
Sympathetic beta stimulation stimulation causes pulmonary vasculature to _______ and causes bronchioles to ________
vasodilate and dilates bronchioles
Which type of receptors are more prevalent within the lungs: alpha or beta?
Alpha
Sympathetic stimulation causes (vasodilation or vasoconstriction) because:
Relatively more vasoconstriction because alpha receptors are more numerous than beta receptors
Name 5 factors that cause vasoconstriction within the lung
1. Catecholamines
2. Angiotensin II
3. Histamine
4. PGF 2a
5. Endothelins
Name 3 pulmonary vasodilators:
1. NO
2. PGE2 (prostaglandin)
3.PGI2 (prostacyclin)
PGF2a = ?
Who should never receive this drug?
Hemabate; never give an asthmatic hemabate because it causes pulmonary vasoconstriction
Endothelins cause _______ and ________.
Pulmonary vasoconstriction and platelet inhibition
What is the most important influence on pulmonary vasomotor tone?
Hypoxia
Acute and chronic hypoxia increases _______
Pulmonary vascular resistance
What is the benefit/intended effect of hypoxic pulmonary vasoconstriction?
VQ matching
What are normal pulmonary SBP, DBP, and MAP?
25/8, mean 15
PAP = _______
RV pressure, but diastolic is higher d/t pulmonic valve
Pulmonary capillary pressure:
7 torr
Pulmonary capillary wedge pressure estimates _________, but overestimates it by _________.
PCWP = LVDP but overestimates by 2-3 torr
Pulmonary lymphatics begin in connective tissue surrounding ________
Terminal bronchioles
Lymphatics course to the _______ and then primarily empty into ________
Course to the hilum and primarily drain into the right lymphatic duct
Lymphatics remove _______ and _____ that enter the alveoli
Particulate matter and protein
What effect does chronic congestion/pulmonary edema have on lymphatics?
Increase capacity
Residual volume: definition and average volume
Air remaining in lungs following maximal exhalation; cannot be voluntarily removed from lungs; 1200ml
Expiratory reserve volume: definition and volume
Maximal amount of air that can be expired from normal end expiration; 1100 ml
Average TV
500 ml
Inspiratory reserve volume: definition and volume
Maximal amount of air that can be inhaled following normal inhalation; 3000 ml
Inspiratory capacity =
IC = TV + IRV; 3500 ml
Maximal inhalation from normal expiratory level
Vital capacity =
VC = IRV + VT + ERV; 4500 ml
Maximal amount of air expired from maximal inhalation
FRC =
Volume of air remaining in lungs at end expiration; FRC= RV + ERV; 2300 ml
TLC =
5800 ml; volume of air in lungs at maximal inhalation; RV + ERV + TV +IRV
Name 5 conditions/factors that increase the closing volume:
Pregnancy, obesity, COPD, CHF, aging, supine positioning
Increased closing volume leads to pulmonary _______
shunting
Respiratory quotient:
0.8; ratio of CO2 produced to O2 consumed
Pulmonary vascular resistance = (1/?) of systemic
1/8
Ventilation and perfusion are greatest in zone ____
3
Zone 1: relationship between Pa, PA, and PV
PA>Pa>Pv
Zone 2: relationship between Pa, PA, and PV
Pa>pA>Pv
Zone 3: relationship between Pa, PA, and PV
Pa>Pv>PA
Where should the tip of a PA catheter lie?
Dependent portion of the lung (zone 3) where both arterial and venous pressure are greater than alveolar pressure and there is continuous blood flow leading to the left heart
What factors tend to hold fluid in the pulmonary capillaries? Which factors encourage movement into the interstitium?
Plasma colloid oncotic pressure holds fluid within the capillaries; interstitial colloid osmotic pressure, capillary hydrostatic pressure, and negative interstitial fluid pressure encourage fluid movement into interstitium
Under normal circumstances, the net of forces favors movement of fluid:
into the interstitium
Which does pulmonary edema affect more: O2 or CO2?
O2; CO2 is 20 times more diffusible
Pulmonary edema can be caused by any factor that:
Any factor that increases pulmonary interstital pressure into positive range
Pulmonary edema will not occur until pulmonary interstital pressure exceeds
Plasma colloid oncotic pressure (28 torr)
______ % of blood flow goes to R. lung and ______% to L. lung
55% Right, 45% left
Dependent alveoli are the _______ compliant and receive the ________ blood flow
Most compliant and best perfused
zone 1: _______like
Dead space like
Zone where capillary flow is variable with respiration
Zone 2
Zone where capillary flow is continuous
Zone 3
Zone 3: ______ like
Shunt like- continuous blood flow, but could have decreased ventilation
Why is lateral position worse than supine from a pulmonary standpoint?
Abdominal contents compress the dependent lung which would otherwise have the best VQ characteristics
What effect does PEEP have on pulmonary dynamics?
Expands zone 1 (increases alveolar size such that PA may be >Pa)
VQ matching is 1:1 at about the level of __________
the third rib
Treatment for negative pressure pulmonary edema
Correct underlying cause, administer O2/CPAP, intubation/ventilation w/PEEP as necessary to support oxygenation; consider steroids to stabilize pulmonary capillary membranes; support hemodynamics (morphine/nitroglycerin to decrease preload and inotropes to promote forward flow)
_________ and ________ are a cause of normal physiologic shunting and venous admixture
Bronchopulmonary anastomoses and thebesian veins
General anesthesia results in a ________% shunt, due to:
10% shunt d/t supine positioning, positive pressure ventilation (more even distribution of flow/decreased VQ matching), decreased CO (especially with PEEP), and atelectasis
________ decrease hypoxic pulmonary vasoconstriction and _______ do not
volatile anesthetics decrease effectiveness of Hypoxic pulmonary vasoconstriction; IV anesthetics do not
Although general anesthetics _______ chest wall compliance, they ________ FRC which leads to an overall _________ in compliance
Increase chest wall compliance, but decrease FRC which leads to an overall decrease in compliance under GA
Volatile anesthetics decrease the ventilatory response to _______, _______. and _______
CO2, acidosis, and hypoxia
Blood spends approximately _______ seconds in the pulmonary system, with _______ in the pulmonary capillaries, but it only needs approx ________ seconds for gas exhchange
spends 4-5 seconds in system, 0.75 in capillaries, but only needs 0.25 seconds for gas exchange under normal conditions
CO2 is _______x more diffusible than O22
20x
One lung ventilation causes _______ through non-dependent lung
Shunt through non-dependent lung
The solubility coefficient for O2 in plasma:
CO2:
O2 0.003 ml/dl
CO2: 0.06 ml/dl
How much O2 is bound to each Hgb molecule?
1.36ml/ g Hgb/100ml
What layers must O2 diffuse through to get out of alveolus and into blood?
1.Alveolar fluid layer (with surfactant)
2. Simple squamous epithelium
3. Epithelial basement membrane
4. Interstitial space
5. capillary basement membrane
6. capillary endothelial membrane
The total surface area of the respiratory membrane is:
50-100m2
Total volume of blood in pulmonary capillaries is:
60-140 ml
Dalton's Law:
Law of partial pressures; each gas in a mixture exerts its own pressure proportional to it concentration in the mixture
Pressure of gas in a solution is determined by its _________. The less dissolved, the _________
Solubility coefficient; less soluble = less dissolved in solution = higher pressure
Solubility of gas in a liquid is described by ________ Law.
Henry's Law
An example of Henry's Law:
Bubbles in a soda can
Concentration of a dissolved gas in solution = ________ x _________
Pressure x solubility coefficient
Fick's Law:
Diffusion is proportional to pressure gradient across membrane/ concentration gradient, surface area of the membrane, and diffusion coefficient (calculation includes molecular weight), and inversely proportional to membrane thickness
Diffusion capacity:
Volume of gas that diffuses through membrane each minute per each pressure difference of 1mm Hg
Normal diffusion capacity for O2:
231 ml/minute
How can the body increase diffusion capacity?
1. Opens dormant pulmonary capillaries (increases surface area)
2. Better VQ matching
How does negative pressure pulmonary edema happen?
Laryngospasm or occluded ETT + large inhalation generates extremely negative intratoracic pressure which pulls fluid from the pulmonary capillaries
The dorsal and ventral respiratory groups, along with projections of CN _____ and _______ are located within the
Tractus solitarius
Pulmonary embolism causes ________ breathing, wherease pulmonary vascular congestion causes _________
PE: Rapid, shallow breathing
Pulmonary vascular congestion = hyperpnea
The trachea extends from C_______ to T_______
C6-T4/5
Average adult minute ventilation:
5L