Lung Volumes Flashcards
What is the term for the amount of air moved in or out each breath and how much is it usually?
Tidal volume (500mL/half a liter)
What is the term for the maximum volume one can inspire above normal inspiration and how much is it usually?
Inspiratory Reserve Volume (3000mL)
What is the term for the maximum volume one can expire below normal expiration and how much is it usually?
Expiratory Reserve Volume (1100mL)
What is the term for the volume of air left in the lungs after maximum expiratory effort and how much is it usually?
Residual Volume (1200mL)
Which volumes of the lung are able to be measured by spirometer?
Tidal volume Inspiratory Reserve Volume Expiratory Reserve Volume Inspiratory Capacity Vital Capacity
What volumes of the lung cannot be measured by spirometer?
Total Lung Capacity
Functional Residual Capacity
Residual Volume
What is the term for the volume of air left in the lungs after a normal expiration?
Functional residual capacity
What lung volume is the balance point of lung recoil and chest wall forces?
Functional residual capacity
What is the term for the maximum volume one can inspire during an inspiratory effort?
Inspiratory capacity
What is the term for the maximum volume one can exchange in a respiratory cycle?
Vital capacity
What is the term for the volume of the air in the lungs at full inflation?
Total lung capacity
What encompasses the FRC?
RV+ERV
What encompasses the IC?
TV+IRV
What encompasses the VC?
IRV+TV+ERV
What encompasses the TLC?
IRV+TV+ERV+RV
What method is used to measure RV, FRC, and TLC instead of a spirometer?
Helium dilution method
Which is easiest to measure: RV, FRC, or TLC?
FRC
Once FRC has been determined, how could you find RV?
RV = FRC-ERV
Once FRC has been determined, how could you find TLC?
RV+VC
Which lung volumes are decreased with restrictive lung conditions?
VC, IRV, IC (issues with inspiration)
What is the difference between how obstructive lung conditions and restrictive lung conditions affect the lungs?
Obstructive - decreased flow rate
Restrictive - decreased expansion
Which lung volume exhibits the most dramatic change in volume with restrictive lung conditions?
VC (decreases)
Why is maximum ventilatory volume tested for only 12 seconds?
Avoid problems that can arise from hyperventilation
How do we find minute respiratory volume?
Respiratory rate X tidal volume
What is the problem that results from both restrictive and obstructive lung conditions?
Combined pulmonary disease
Ankylosing spondylosis presents what type of lung condition: restrictive or obstructive?
Restrictive
Which is a result of decreased forced expiratory volume (FEV): restrictive or obstructive lung conditions?
Obstructive
Which is a result of decreased VC: restrictive or obstructive lung conditions?
Restrictive
Compare the surface areas of the trachea and alveoli?
Trachea - 2 square centimeters
Alveoli - 50-100 square meters
What is the branching pattern in the respiratory system?
Trachea –> bronchi –> bronchioles –> respiratory bronchioles –> alveolar ducts to sacs –> alveoli
How many total generations of branching are there?
20: 11 in bronchi, 5 in bronchioles, 4 in respiratory bronchioles
Where can cartilage be found in the respiratory airways?
Trachea
Where is cartilage absent in the respiratory airways?
Bronchioles
About how many alveoli are there?
300 million
Compare the surface area of the skin to the alveoli?
Skin- 2 square meters
Alveoli - 50-100 square meters
What is dead space?
Area where gas exchange cannot occur
Where can we find dead space?
Most of the airway volume
About how much anatomical dead space do we see in the airways?
150 mL
What makes up the physiological dead space?
Anatomical dead space + nonfunctional alveoli
How is dead space calculated?
Using a pure oxygen inspiratior and measuring nitrogen in expired air
What is alveolar volume?
FRC-dead space
About how much is alveolar volume?
2150 mL (FRC is 2300 mL minus dead space which is 150 mL)
At the end of normal expiration, where is most of the FRC located?
Level of alveoli
About how many breaths does it take for a full turnover of alveolar air?
6-7 breaths(slow)
Which has a stronger effect on the airways: direct or indirect sympathetic stimulation?
Indirect
Why is direct effect of sympathetic stimulation on the airways weak?
Sparse innervation
What makes up the indirect sympathetic stimulatory effect on the airways?
Circulating epinephrine
What effect does the sympathetic nervous system have on the airways?
Dilation
Which receptors are responsible for the dilatory effect of the sympathetic nervous system on the airways?
Beta receptors
What is the parasympathetic effect on the airways?
Constriction
Which receptors are responsible for the constricting effect of the parasympathetic nervous system on the airways?
Muscarinic receptors
What effect do both VIP and NO have on the airways?
Bronchodilitation
What are the NANC nerves?
Non-adrenergic, non-cholinergic
What is the function of the NANC nerves?
Inhibitory function by release of VIP and NO
Stimulatory function leading to mucus secretion, vascular hyperpermeability, cough, neurogenic inlammation
What kind of receptors are involved with the reflex control of breathing and the cough reflex?
Stretch receptors which are slow adapting receptors
Slow adapting receptors are associated with what part of the proximal airways?
Smooth muscle (afferent nerves)
Rapidly adapting receptors of afferent nerves are sensitive to what substances?
Mechanical stimulation, protons, low Cl- solutions, histamine, cigarette smoke, ozone, serotonin, PGF-2alpha
Which high-density fibers are involved in the autonomic control of airways?
C-fibers
What neuropeptides are contained in C-fibers?
Substance P, neurokinin A, calcitonin gene-related peptide
What substance can selectively stimulate the C-fibers in the airways?
Capsaicin (found in peppers)
What else can activate the C-fibers in the airways?
Bradykinin, protons, hyperosmole solutions, and cigarette smoke
What is the result from histamine binding to H1 receptors?
Constriction
What is the result from histamine binding to H2 receptors?
Dilation
What is the result from prostaglandins E series?
Dilation
What is the result from prostaglandins F series?
Constriction
Elicit constriction of the airways due to environmental pollution is mediated by what?
Parasympathetic reflex and local constrictor responses
What kinds of things constitute as environmental pollution?
Smoke, dust, sulfur dioxide
What organ regulates HCO3-?
Kidneys
What organ regulates CO2?
Lungs
What is the effect of metabolic acidosis on ventilation?
Increased (HCO3- less than 24)
What is the effect of metabolic alkalosis on ventilation?
Decreased (HCO3- >24)
What is the normal level of HCO3-?
24mEq/L
What is the normal level of CO2?
40 mmHg
What is the effect of respiratory acidosis on ventilation?
Increased (CO2 > 40)
What is the effect of respiratory alkalosis on ventilation?
Decreased (CO2 less than 40)
Which is thicker: pulmonary artery wall or aorta?
Aorta (pulmonary artery wall is 1/3 as thick)
Which is thicker: right ventricle of left ventricle?
Left ventricle (right ventricle is 1/3 as thick)
Why do pulmonary arterties have larger lumens?
To be more compliant
To operate under a lower pressure
To accommodate 2/3 of SV from right ventricle
Compare pulmonary veins to systemic veins.
Pulmonary veins = shorter but have similar compliance
What is the total pulmonic blood volume?
450 mL (9% of total blood volume)
How can mitral stenosis affect pulmonary volume?
Increased by 100%
Are shifts in total pulmonic blood volume more effective on pulmonary or systemic circulation?
Pulmonary
What arteries branch off of the thoracic aorta to supply oxygenated blood to the supporting tissue and airways of the lung?
Systemic bronchial arteries
What is the venous drainage of the lungs?
Half into the azygous vein, half into pulmonary veins
What is seen when drainage occurs into pulmonary veins?
LV output is slightly greater than RV output (1%) and some deoxygenated blood is dumped into oxygenated pulmonary venous blood