Term
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Definition
| the volume inspired or expired with each normal breath. |
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Term
| Inspiratory reserve volume (IRV) |
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Definition
is the volume that can be inspired over and above the tidal volume.
is used during exercise. |
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Term
| Expiratory reserve volume (ERV) |
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Definition
| is the volume that can be expired after the expiration of a tidal volume. |
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Term
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Definition
is the volume that remains in the lungs after a maximal expiration.
cannot be measured by spirometry. |
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Term
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Definition
volume of conducting airways
normally ~150mL or patients wt in lbs |
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Term
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Definition
is a functional measurement
is the volume of the lungs that do not participate in gas exchange |
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Term
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Definition
V(dead) = V(total) * [ (PAco2 - PEco2)/(PAco2) ]
PAco2 is alveolar CO2 partial pressure
PEco2 is expired CO2 partial pressure |
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Term
| Inspiratory Capacity (IC) |
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Definition
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Term
| Functional Residual Capacity (FRC) |
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Definition
FRC = ERV + RV
cannot be measured by spirometry |
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Term
| Total Lung Capacity (TLC) |
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Definition
TLC = IRV + TV + ERV + RV
cannot be measured by spirometry |
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Term
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Definition
VC = IRV + TV + ERV
or
VC = IC + ERV |
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Term
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Definition
| Tidal Volume * Breaths/min |
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Term
| Alveolar Minute Ventilation |
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Definition
| (Tidal Volume - Dead Space) * Breaths/min |
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Term
|
Definition
C = V/P
Describes distensibility of lungs and chest wall
inversely related to stiffness/elastance (both of which depend on elastic tissues)
dV/dt |
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Term
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Definition
| Transmural Pressure = Palveolar - Pintrapleural |
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Term
| Intrapleural Pressure is (sign) |
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Definition
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|
Term
A patient with emphysema shows
A patient with fibrosis shows |
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Definition
increased lung compliance, which eventually results in a new, higher FRC - patients may exhibit a barrel-chest
decreased lung compliance, and eventually a new lower FRC |
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Term
|
Definition
P = 2T/r
P is collapsing pressure on alveolus
T is surface tension
r is the radius of the alveolus |
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Term
| Application of Law of Laplace to large and small alveoli |
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Definition
Large alveoli have low collapsing pressures and are easy to keep open
Small alveoli have high collapsing pressures and have a tendency to collapse (atelectasis) |
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Term
|
Definition
lines the surface of alveoli, reducing surface tension
is synthesized by type II alveolar cells and is primarily dipalmitoyl phosphatidylcholine (DPPC - a phospholipid) |
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Term
| Neonatal Respiratory Distress Syndrome |
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Definition
| prematurely born infants lack surfactant, which leads to lung collapse (atelectasis) as well as a difficulty in reinflating the lungs (decreased compliance) and hypoxemia (as a result of decreased V/Q) |
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Term
|
Definition
Q = dP/R
Q is airflow
dP is a pressure gradient
R is airway resistance |
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Term
| Poiseuille's law and airway resistance |
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Definition
R = [8(eta)L] / [(pi)r^4]
eta = viscosity of inspired gas
L = length of airway
r = Airway Resistance |
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Term
| Bronchial Smooth Muscle Contraction |
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Definition
| Parasympathetic Stimulation, Irritants, and asthma inducing substances constrict the airways, reduce radii, and increase resistance to flow |
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Term
| Bronchial Smooth Muscle Relaxation |
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Definition
| Sympathetic stimulation and Sympathetic agonists (isoproterenol) dialate airways via beta-2 receptors, increasing radii and decreasing airway resistance. |
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Term
| Lung Volumes and Airway Resistance |
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Definition
High LV leads to decreased airway resistance - used as a compensatory mechanism for patients with asthma
Low LV leads to increased airway resistance, and potentially even collapse |
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Term
| Inspired Gas Voscosity/Density |
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Definition
alters airflow
during deep-sea diving air density and resistance are increased
low-density gases reduce airflow resistance |
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Term
Graphs of Breath Volume (L), (Intrapleural Pressure (cm H20), and Alveolar pressure
Resemble what from inspiration to expiration? |
|
Definition
vol - cos^2(x) from -pi/2 to pi/2 (sharper slope during inspiration)
lowercase greek nu
sin(x) from -pi to pi |
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Term
| Chronic Obstructive Pulmonary Disease (COPD) |
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Definition
| Increased airway resistance leads patients to expire slowly with pursed lips |
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Term
|
Definition
obstructive disease which impares expiration
decreased FVC, decreased FEV1 and decreased FEV1/FVC
FRC is increased as a coping mechanism, but during distress, air which should leave may become trapped |
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Term
|
Definition
combination of chronic bronchitis and emphysema
obstructive disease with increased lung compliance and impaired expiration
decreased FVC, decreased FEV1, decreased FEV1/FVC
Air that should be expired is not. Increased FRC can result in barrel chest |
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Term
|
Definition
pink puffers - primarily emphysema - mild hypoxemia, normal levels of Pco2 (since alveolar ventilation is maintained
blue bloaters - primarily bronchitis - severe hypoxemia with cyanosis. alveolar ventilation is not maintained, therefore they exhibit hypercapnia (high alveolar Pco2) - right ventricle failure and systemic edema are common |
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Term
|
Definition
Restrictive disease, decreased lung compliance due to impaired inspiration.
decrease in ALL lung volumes.
FEV1 is decreased less than FVC therefore FEV1/FVC may be normal or increased |
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Term
|
Definition
| living at high altitude where external Po2 is decreased leads to increased synthesis of 2,3-DPG which binds hemoglobin and facilitates unloading of O2 in the tissues |
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Term
|
Definition
does not interact strongly with 2,3-DPG
therefore the curve has an increased o2 affinity, decreased p50 and is shifted left |
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Term
| Medullary respiratory center |
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Definition
| located in reticular formation |
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Term
|
Definition
responsible for inspiration and basic rhythm of breathing
inputs from vagas (relays mechano and chemo receptor of lung) and glossopharyngeal (relay chemo receptor outside lung)
output follows phrenic nerve |
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Term
| Ventral Respiratory Group |
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Definition
responsible for expiration
inactive during normal breathing
activated for exercise |
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Term
|
Definition
located in lower pons
stimulates inspiration as prolonged deep gasps |
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Term
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Definition
upper pons
inhibits inspiration - regulates inspiratory volume and respiratory rate |
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Term
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Definition
Breathing under voluntary control
Hypoventilation leads to increased Pco2 and decreased Po2. A previous period of hyperventilation extends the period of breath holding. |
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Term
| High Altitude Adaptations |
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Definition
| Hypoxemia -> hyperventilation, erythropoietin and 2,3-DPG production, and pulmonary vasoconstriction |
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