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213 Cards in this Set
- Front
- Back
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What is the main function of the lungs?
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To get oxygen into the tissues and remove Carbon Dioxide from the body. It also helps to maintain acid/base balance.
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What is the endocrine function of the lungs?
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To convert angiotensin I to angiotensin II, which is done by ACE.
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What does the symbol P mean in respiratory physiology?
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Partial pressure
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What does the symbol V mean in respiratory physiology?
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Volume of gas
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What does the symbol Q mean in respiratory physiology?
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Blood Volume/blood flow
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What does the symbol C mean in respiratory physiology?
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Concentration
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What does the symbol F mean in respiratory physiology?
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Fractional concentration
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What does the symbol S mean in respiratory physiology?
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Saturation
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What is the fractional concentratino of oxygen in normal air?
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About 21%
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What does the symbol I mean in respiratory physiology?
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Inspired Air
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What does the symbol E mean in respiratory physiology?
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Expired air
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What does the symbol A mean in respiratory physiology?
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Alveolar gas
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What does teh symbol a mean in respiratory physiology?
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arterial blood
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What does teh symbol v mean in respiratory physiology?
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venous blood
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What does the symbol c mean in respiratory physiology?
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capillary blood
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What does the symbol T mean in respiratory physiology?
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Tidal gas
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What does the symbol D mean in respiratory physiology?
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Dead space
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What is used to measure diffusion pressure of the lungs?
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A single breath of carbon monoxide
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Explain Dalton's law of partial Pressure.
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Dalton's law of partial pressure states that the partial pressure exerted by each gas in a mixture of gases, like the atmosphere, is independent of the other gases present and is equal to the pressure that would exist if that gas alone occupied the whole volume.
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What is barometric oxygen pressure? (atmospheric pressure)
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760 mmHg at sea level
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What gas is most abundant in our atmosphere?
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Nitrogen (79%)
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What percentage of our atmosphere is made up of oxygen?
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About 21%
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According to Dalton's law, what is water vapor pressure in dry air?
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0 mmHg
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What is water vapor pressure in the humidified tracheal air?
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47 mmHg
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Why can't we have dry air moving in and out of our lungs?
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Because it causes damages to the tissue.
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What is the partial pressure of oxygen in inspired humidified air?
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(760-47)x0.21=150mmHg
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List the funcitonal anatomical parts of the conducting zone of the respiratory tree.
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Trachea, Bronchi, Bronchioles, Terminal bronchioles
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List the functional anatomical parts of the respiratory zone of the respiratory tree.
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Respiratory bronchioles, Alveolar ducts, alveolar sacs
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What happens in the conducting zone of the respiratory tree?
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This zone is anatomical dead space. These areas don't contribute at all to gas exchange.
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What happens in the respiratory zone of the respiratory tree?
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This is the area of the respiratory tree that contributes to gas exchange due to the little bumps that create surface area. Here, membrane exchange of different nutrients can occur.
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What gas is most abundant in our atmosphere?
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Nitrogen (79%)
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What percentage of our atmosphere is made up of oxygen?
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About 21%
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According to Dalton's law, what is water vapor pressure in dry air?
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0 mmHg
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What is water vapor pressure in the humidified tracheal air?
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47 mmHg
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Why can't we have dry air moving in and out of our lungs?
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Because it causes damages to the tissue.
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What is the partial pressure of oxygen in inspired humidified air?
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(760-47)x0.21=150mmHg
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List the funcitonal anatomical parts of the conducting zone of the respiratory tree.
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Trachea, Bronchi, Bronchioles, Terminal bronchioles
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List the functional anatomical parts of the respiratory zone of the respiratory tree.
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Respiratory bronchioles, Alveolar ducts, alveolar sacs
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What happens in the conducting zone of the respiratory tree?
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This zone is anatomical dead space. These areas don't contribute at all to gas exchange.
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What happens in the respiratory zone of the respiratory tree?
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This is the area of the respiratory tree that contributes to gas exchange due to the little bumps that create surface area. Here, membrane exchange of different nutrients can occur.
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How does the air move through the conducting zone of the respiratory tree?
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By bulk flow
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How does the air move through the respiratory zone of the respiratory tree?
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By diffusion
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Define Tidal Volume (Vt)
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Tidal volume is the air moving in and out of the lungs in one single breath at rest.
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Define Minute Ventilation (Ve)
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Minute ventilation is the volume of air moved into or out of the lungs per minute. Basically, the minute ventilation is calculated by taking the Tidal volume and multiplying it by the frequency of breaths per minute. This includes air moving through the anatomical dead space as well as teh respiratory areas.
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Define anatomical dead space.
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Anatomical dead space is the areas in the respiratory system that are not involved with gas exchange. This is normal in all individuals and is made up of the mouth, pharynx, larynx, trachea, and bronchi.
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What is fowler's method?
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Fowler's method uses a single breath of 100% oxygen to measure anatomical dead space.
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What is physiological dead space?
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Physiological dead space is when teh "funcitonal" areas of the lungs (respiratory zone) do not have adequate gas exchange. This doesn't exist in normal individuals and is usually an indication of respiratory problems.
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Which is lower, Arterial O2 or Alveolar O2, and why?
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Arterial O2 is less than Alveolar O2. This is because teh venous add mixture, that is dumping deoxygenated blood into the left ventricle.
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What is the relationship between Alveolar CO2 and Arterial CO2?
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They are identical. This is because absolute diffusion is happening here.
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How does oxygen get delivered to the tissues?
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There is high gradient for oxygen to move from the alveoli to the venous blood, so that the oxygen can then be pumped to the rest of the body through the arterial blood supply.
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How does carbon dioxide get expired from the body?
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There is a gradient for carbon dioxide to move from the venous blood to the alveolar, where it can then be expired.
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Define Alveolar Ventilation
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Alveolar ventilation is the air that moves in and out of teh respiratory zone. This is calculated as the minute ventilation minus the anatomical dead space ventilation.
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Does alveolar ventilation increase when tidal volume increases or when frequency of breaths increases?
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It increases when tidal volume increases. Just by increasing frequency and getting more shallow breaths, you are not moving air in and out of the respiratory zones, but by increasing tidal volume, you are.
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How do we estimate the anatomical dead space in an individual?
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For each pound of weight that a person has, we estimate about 1 mL of anatomical dead space.
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What is the respiratory Quotient (RQ)?
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It is the amount of carbon dioxide produced divided by the amount of oxygen consumed by cellular metabolism. VCO2/VO2
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What is the respiratory quotient for carbohydrates?
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1- we produce teh same amount of carbon dioxide as the oxygen that we consume.
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What is the respiratory quotient for fats?
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0.7-because we make other by products, other than Carbon dioxide for the oxygen that we consume.
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What is the respiratory quotient for protein?
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0.8
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What respiratory quotient do we use for a mixed diet?
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0.8
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Inspired air contains how much Carbon dioxide?
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Almost none.
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Increased cellular metabolism causes an increase or decrease in PCO2 in the alveoli?
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Increase.
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What are some causes of increased CO2 production?
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Exercise, fever, hyperthyroidism
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Increased alveolar ventilation (moving more fresh air in) will cause a decrease, or increase in alveolar PCO2?
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Decrease.
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What hormone is primary responsible for the level of metabolism in tissues?
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Thyroid Hormone
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When you blow off CO2, you are also blowing off what, and what occurs as a result of this?
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When you blow off CO2, you are also blowing off acid, and as a result, you make your body more basic.
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Inspired air contains approximately what percentage of oxgygen?
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21%
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At higher altitudes, is barometric pressure higher or lower?
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Lower
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If you increase metabolism, you need more oxygen. How is this accomadated for?
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By increasing uptake, normally by increasing ventilation.
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What is the Alveolar Gas Equation?
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PAO2=PIO2 - PACO2/R
Alveolar Oxygen equals Partial pressure of inspired oxygen minus alveolar CO2 divided by teh respiratory quotient. Remember that alveolar CO2 is obtained from arterial CO2. |
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What is teh alveolar gas equation used to find?
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It is used to determine the alveolar-Arterial Oxygen difference. If there is a difference that is more than 12 mmHg, then there is most likely a problem that is affecting teh diffusion of oxygen from the alveolus into the arterial blood.
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What is the normal value for inspired PO2?
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150mmHg
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What is teh normal value for PaCO2? (Arterial CO2)
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40 mmHg
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What is the normal value for the respiratory quotient?
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0.8
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What effect does the sympathetic nervous system have on pulmonary ventilation and what receptors does it affect?
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It has a weak bronchodilation effect and acts on teh Beta 2 receptors. The beta 2 receptors cause smooth muscle to relax, causing bronchodilation.
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What effect does teh parasympathetic nervous system stimulation have on pulmonary ventilation?
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It causes bronchoconstriction and exacerbates asthma. It exacerbates asthma, because in asthma, the bronchos are already constricted and it causes them to constrict more.
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Define Eupnea
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Normal quiet breathing (appropriate ventilation)
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Define Hyperpnea
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Increased ventilation (rate and depth) that matches metabolic requirements. Occurs during exercise and fever.
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Define hyperventilation
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Excess ventilation that reduces alveolar PCO2 (and arterial PCO2)
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Define hypoventilation
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Deficient ventilation that increaes alveolar PCO2 (and arterial PCO2)
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What is happening when you exercise, hyperventilation or hyperpnea?
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Hyperpnea-all of the partial pressures are remaining normal, just the ventilation rate increases.
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Define Tachypnea
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Increased frequency of breathing. Minute ventilation may or may not change depending on what happens to tidal volume.
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Define Dyspnea
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subjective feeling of "shorthness of breath". May occur in the absence of hypoventilation.
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Define Kussmaul's respiration
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deep, rapid respiration most often associated with acidosis (air hunger). Often seen in diabetics
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Define Orthopnea
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dyspnea upon lying down, feeling of shortness of breath when one lays down. This occurs because blood pools in the lungs due to gravitation effects and is common in cardiac failure.
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Define Apnea
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Temporary cessation of breathing
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Pulmomary circulation is under higher or lower pressure compared to systemic circulation?
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Lower
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The apex of the lung is what part?
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The top
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The base of the lung is what part?
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The bottom
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Pulmonary circulation is what part of the heart, right or left?
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Right
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Why does the left side of the heart have a higher amount of pressure than the right heart?
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Because the left heart has to pump blood to the whole body (systemic circulation) and the right has to pump blood only to the lungs (pulmonary circulation).
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The pulmonary artery carries deoxygenated or oxygenated blood?
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Deoxygenated
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The pulmonary vein carries oxygenated or deoxygenated blood?
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Oxygenated
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Lung inflation upon inspiration tends to expand extra alveolar vessels (vessels outside of teh alveolar area) while collapsing alveolar blood vessels. What happens as a result of this?
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Temporary overload on the right ventricle. This is where you start to hear a physiological splitting of teh second heart sound.
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Decreased alveolar PO2 causes what?
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hypoxic vasoconstriction
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Recruitment and distension of vascular vessels causes an increase or decrease in resistance?
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Decrease, because you are opening more vessels with recruitment, and expanding them with distension.
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During inspiration, the alveolar vessels are collapsed or open?
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Collapsed, because the lungs are pushing down on the blood vessels. The extra alveolar vessels are vessels not exactly next to the alveolus, so these expand when lung volume is high, but the alveolar vessels directly below the alveolus collapse.
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During expiration, the alveolar capillaries are nice and wide or compressed?
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Nice and wide.
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What does hypoxia mean?
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A lack of oxygen
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If one alveolia is hypoxic, there is an oxygen deficit that causes vasoconstriction of that vessel. What happens as a result of this?
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Blood is shunted away from the hypoxic area, supplying more blood to other areas. This is the opposite of what you would see in systemic tissues.
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What is regional hypoxia?
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When one alveoli is hypoxic, the vessels to this alveoli are constricted and blood is shunted away from the hypoxic region as a protective measure and supplied to areas of the lung that are still funcitonal. This is often seen in a tumor in teh lung, because the tumor has a hypoxic effect and gas cannot be exchanged tehre, so the blood is shunted elsewhere where nutrients and oxygen can be absorbed through the alveoli.
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What is generalized hypoxia?
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When many alveoli are hypoxic. This occurs in high altitudes and causes an overload on the right ventricle due to pulmonary constriction.
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The partial pressure of oxygen increases or decreases from the air to tissues?
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Decreases, as a result of a slight diffusion problem.
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The biggest drop in PO2 from the air to tissues occurs in where?
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Between the arterioles and teh tissues.
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What do anatomical shunts do?
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They reduce arteriole oxygen and cause an increase in arteriole CO2. When large, these will cause hypoxia and hypercapnia (high CO2).
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Giving 100% oxygen to a person with an anatomical shunt will do what to arterial PO2?
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It will do nothing to correct arterial PO2. But if the person has a diffusion problem, it will make them better.
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According to Fick's law, net diffusion is proportional tot he area of the membrane divided by the thickness of the membrane. True or false?
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True
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In applying Fick's law to medicine, can the diffusivity of a certain gas change?
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Not in medicine. In medicine we keep the diffusivity constant.
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In applying Fick's law, how does teh area change?
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The area changes because alveolar walls can be broken down.
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In applying Fick's law, how can thickness change?
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Thickness can be affected by things such as pneumonia.
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In Fick's law, the diffusion coefficient, D, is primarily determined by what?
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The Solubility of the gas
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Define Alveolar Ventilation
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Alveolar Ventilation is teh volume per minute of fresh air moving into the alveoli for gas exchange. This is teh total ventilation minus the anatomical dead space.
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Define perfusion
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Perfusion is teh amount of blood per minute perfusing teh pulmonary capillaries.
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Where are ventilation and perfusion at their highest, at the apex of the lungs, or at the base of the lungs?
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They are highest at the base and lowest at the apex. This is due to gravity. Gravity affects both blood and air, but has a greater affect on blood.
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What is the V/Q ratio?
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The V/Q ratio is the ventilation to perfusion ratio.
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Where is the V/Q ratio the highest and what does this result in?
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It is highest at the apex of the lung and lowest at the base, resulting in Wasted ventilation at the apex, and wasted perfusion at the base.
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Ventilation and blood flow are highest at what part of the lung?
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At the base of the lung
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There is very little blood flow at the top of the lung, and a lot of wasted ventilation, true or false.
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True
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Where in the lung is blood flow equal to ventilation?
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In the midlung
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The V/Q ratio is highest where in the lung, and what does this mean?
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It is highest at the apex of the lung, and this means that the partial pressure of oxygen is higher at the apex and the CO2 is lower at the apex because of the excess ventilation occurring at the apex.
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Most oxygen is carried in the blood bound to what?
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Hemoglobin
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Most carbon dioxide is carried in what form?
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in the form of HCO3-
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Within tissue cells, oxygen is carried how?
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By myoglobin and dissolved
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Arteriole PO2 is referring only to the oxygen that is dissolved in the blood, not anything that is bound to hemoglobin, true or false?
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True
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Which do we have more of in our bodies, CO2 or O2?
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CO2
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PO2 is referring to what type of oxygen?
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The oxygen that is dissolved in the plasma.
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Saturation is referring to what type of oxygen?
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Oxygen bound to hemoglobin (saturation of hemoglobin with O2).
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The oxyhemoglobin dissociation curve is said to have two regions, what are these regions?
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A steep region and a plateau region.
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What is meant by P50 in the oxyhemoglobin curve?
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P50 is the partial pressure at which hemoglobin is 50% saturated. This is normally around 27 mmHg.
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When the hemoglobin curve shifts to the right, what happens to O2 affinity?
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O2 affinity is decreased. P50 is increased, meaning that you need to have more Oxygen around to have the hemoglobin saturated at 50%, so the affinity is less.
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What are some things that cause a shift in the hemoglobin curve to the right, favoring unloading of oxygen by decreasing hemoglobin's affinity for oxygen?
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Increased PCO2, increased H, increased Temperature, and increased BPG.
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What happens to O2 saturation during carbon monoxide poisoning?
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Saturation of Hemoglobin with O2 goes way down in carbon monoxide poisoning because the hemoglobin has a higher affinity of carbon monoxide. Carbon monoxide also shifts the dissociation curve to the left. Also, oxygen that does bind to hemoglobin, does not want to be released.
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What happens to O2 and the dissociation curve in anemia?
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During anemia, the oxygen dissociation curve is shifted to the right. Since there are fewer RBC, the content has gone way down. There is still 100% saturation of the hemoglobin, there are just fewer cells, so less oxygen can be bound.
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What happens in polycythemia?
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There is an inccrease in O2 content, but saturation won't necessarily increase, because only so much oxygen can bind to the hemoglobin.
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Describe the Bohr Effect
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CO2 and H+ reduce the affinity of hemoglobin for O2 and shift the P50 to the right. This helps in the unloading of O2 in the tissues.
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Describe the Haldane Effect
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The presence of higher PO2 in the blood helps for the unloading of CO2 at the lungs.
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CO2 is transported in three forms. What are these forms?
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Dissolved, Carbamino Hemoglobin, and Bicarbonate. Bicarbonate accounts for most of the CO2 transport.
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What is the Chloride shift that occurs in the RBC?
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The formation of HCO3- is in the RBC. This HCO3- is exchanged for a plasma Cl-.
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What is a carbamino hemoglobin?
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When Carbon Dioxide is bound to hemoglobin
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In what way is most of the carbon dioxide transported, and what is the least common way that carbon dioxide is transported?
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The most common way it is transported is as bicarbonate. The least common way is as dissolved CO2. In the middle is the carbamino hemoglobin.
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What are the two pontine CNS control centers of respiration?
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Pneumotaxic area and the apneustic Area.
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What happens when the apneustic area is stimulated?
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It causes apnea, or causes you to stop breathing.
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Stimulation of the pneumotaxic area results in what?
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It causes early termination of inspiration, resulting in increased respiration frequency and reduced tidal volume.
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What are the two medullary centers for controlling respiration?
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The Dorsal Respiratory Group (DRG) and the Ventral Respiratory Group (VRG)
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Where is the Dorsal Respiratory Group located?
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In the Nucleus Tractus Solitarius.
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Which play more of a role in respiration regulation, the pontine areas, or the medullary centers?
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The Medullary centers.
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Describe the DRG.
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The Dorsal respiratory group are the uppe rmotor neurons of inspiration. They stimulate the VRG. The DRG receives input from all peripheral respiratory afferents.
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Describe the VRG.
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The ventral respiratory group contains both inspiratory neurons that project to the inspiratory muscles and expiratory neurons that are quiescent at rest and stimulate the internal costals and abdominal muscles when activated (such as during exercise)
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Which neurons are responsible for deep breathing?
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The VRG
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What are the two types of chemoreceptors that aid in respiration regulation?
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Central and Peripheral
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Where are teh central cehmoreceptors located?
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In the anterior medulla
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What are central chemoreceptors most responsive to?
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They are most responsive to PaCO2 by way of increasing H+ in teh CSF.
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What actually stimulates the central chemoreceptors?
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The Hydrogen ion (which is effected by arteriol PCO2)
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What is driving respiration at rest?
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The central chemoreceptors
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PaCO2 acts indirectly or directly on the central chemoreceptors?
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Indirectly, through the Hydrogen Ion
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How does PaCO2 stimulate the central chemoreceptors? Remember, it is done indirectly.
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It does this indirectly by crossing the blood brain barrier and reacting with water to yeild a hydrogen ion. It is this hydrogen ion that then stimulates the chemoreceptor.
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In what two locations are the peripheral chemoreceptors located?
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In the carotid bodies and in the aortic bodies (mainly in the aortic arch).
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What are peripheral chemoreceptors most responsibe to?
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PaO2
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Which are more reactive, carotid body receptors or aortic bodies?
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Carotid body receptors
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What is the big difference between peripheral and central chemoreceptors?
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Central chemoreceptors are stimulated by PaCO2 and peripheral are most responsive to PaO2.
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Peripheral chemoreceptors take over respiration during what types of states?
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Hypoxic states (such as at high altitudes)
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How do peripheral chemoreceptors work?
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When you get a drop in PO2, you get a lot more stimulation from carotid body nerve fibers, which increases ventilation.
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HCO3- is transported into or out of the CSF in exchange for what to buffer CSF changes in H+?
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Cl-
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During Hypercapnea, does HCO3- leave the CSF or enter the CSF?
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It enters the CSF.When there is a lot of CO2, there is a lot of Hydrogen present in the CSF, so bicarbonate moves into the CSF to neutralize the acidic conditions.
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As you increase the intensity of exercise, what do you do to total ventilation and why?
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You increase the total ventilation, to keep up with the needs of the tissues for oxygen.
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In a steady state of exercise, what should happen to blood gas levels such as O2 and CO2?
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They should remain normal, as should pH.
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Define the Hering-Breuer Reflex.
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This is a set of slowly adapting stretch receptors in airway smooth muscle that during inspiration can protect the lung from prolonged over inflation; they shorten (shut off) inspiration and prolong expiration.
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Why is the Hering-Breuer reflex important in infants?
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Because when infants are born, they are going from liquid breathing to air breathing. This reflex protects them from taking in too much air in their first few breaths and damaging their neonate lungs.
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What are irritant receptors?
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A set of rapidly adapting receptors between airway epithelial cells that detect inhaled noxious compounds such as dust, certain gases and cold air. Stimulation of these produces bronchoconstriction, tachypnea, cough, and tachycardia. It is significant in the pathogenesis of asthma.
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Where are J receptors located?
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They are next to the juxta capillaries.
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What stimulates the J receptors and what happens as a result of stimulation of these receptors?
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Stimulation of the J receptors is done by interstitial edema, such as pneumonia. If you activate these receptors, you get laryngeal closure, apnea, shallow breathing and sometimes embolism.
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What are peripheral receptors and what does stimulation of these cause?
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Peripheral receptors are located in the joints and skeletal muscles. When you start to exercise, these will be stimulated and cause an increase in ventilation.
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What is cortical override?
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Coritical override is when you can voluntarily override some reflexes on a short term basis.
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What is surfactant?
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Surfactant is a detergent that lowers your surface pressure in the lungs.
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What individuals tend to lack surfactant?
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Premature babies.
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What is lung hysteresis
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It refers to the difference of inspiration and expiration.
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Define Air inflation and what is happening during inspiration.
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During inspiration, you are not getting much of a change in pressure for a change in volume at the befinning but later on you do. Expiration is more of a hyperbolic change in pressure and surfactant plays a role on this.
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What cells secrete lung surfactant?
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Type II alveolar cells
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What happens to surface tension as alveoli inflate?
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It increases
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What is the major role of surfactant?
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To increase alveolar compliance.
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Define Tidal volume
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The volume of air moved in and out with each breath during quiet respiration
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Define Inspiratory Reserve Volume (IRV)
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The volume of air one can inspire at the end of a normal quiet inspiration (peak of Vt)
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Define Expiratory Reserve Volume (ERV)
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The volume of air one can expire at the end of a normal quiet expiration
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Define Residual volume
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The volume of air left in the lungs after a maximal expiration. This is not measurable by standard spirometry.
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Define Total Lung Capacity (TLC)
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The total amount of air in the lungs at teh end of a maximal inspiration
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Define Vital Capacity (VC or FVC)
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The total amount of air that be expired (down to RV) after a maximal inspiration (from TLC)
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How is Inspiratory Reserve Capacity (IRC) Calculated?
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IRC=IRV+Tidal Volume
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How is Functional Residual Capacity calculated?
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FRC=ERV+RV
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As we normally are sitting here quietly, what do our chest walls have a tendency to do?
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Spring outward.
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The chest wall is like a spring that can be what?
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Compressed or distended.
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The lungs are like a spring that can be what?
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Only extended
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The lungs always have a tendency to what, collapse or expand?
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Collapse
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Intrapleural pressure is always negative and becomes what with inspiration?
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More negative
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When the lungs collapse, they still have some air in them. About how much of the TLC is left in the lungs even after they collapse?
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Approximately 10%
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What holds the chest wall in even though it wants to pop outwards and the lungs out even though they want to go inward?
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The small amount of liquid in the interpleural space. This liquid causes teh pleura to slide very easily, but holds the chest in and th elungs out because they cannot be pulled apart.
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At Functional Residual Capactiy, respiratory system pressure is at zero. What does this mean?
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That the tendency for the chest wall to spring out at this volume is balanced by the lungs to recoid inward. (Equal and opposite)
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What measure is the measure that is really used to assess a patient?
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Vital Capacity
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To measure vital capacity, what has to be done?
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The patient has to have their nose plugged and breathe into a one way valve. They should be in a standing position so that when they blow out, they can lean forward and use their abdominal muscles to breathe more air out of their lungs.
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To be considered abnormal, measured values should be greater than what percentage different than predicted values?
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Greater than 20%
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Define Forced Vital Capacity, or FVC
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The maximum volume of air that can be forcefully exhaled following an inhalation to total lung capacity
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What is FEV1?
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The volume of air exhaled in the first second of an FVC maneuver
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What is a normal FEV1/FVC ratio?
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Approximately 80%
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Define an obstructive lung disease.
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Can't get air out of the lungs. Air is getting trapped in the lugs due to increased lung compliance.
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What is a restrictive lung disease?
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A disease in which respiration is restricted and individuals can't get air into the lungs. The lungs are resisting inspiration.
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Patients suffering from what disease tend to become barrel chested?
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COPD (chronic obstructive pulmondary disorder)
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What is the equal pressure point (or closing volume)?
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Is where the airways begin to collapse as extrabronchiolar pressure exceeds intra-airway pressure (Pressure outside the airways is greater than inside)
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In an individual suffering from COPD, what happens to the equal pressure point?
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The equal pressure point occurs much further down the airways (trapping a lot more air in the lungs than normal).
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In an obstructive lung disease, what happens to lung volume?
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It is much higher than normal
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In a restrictive lung disease, what happens to lung volume?
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It decreases
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What happens to tidal volume in obstructive and restrictive lung diseases?
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It remains about normal
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What happens to residual volume in individuals with COPD?
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It increaes from normal
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What happens to residual volume in individuals with restrictive lung disease?
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It decreases from normal
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What happens to FVC in an obstructive lung disease?
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It is greatly reduced
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What happens to FVC in a restrictive lung disease?
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It remains normal, because these individuals don't have trouble getting air out, just getting air in.
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