Pulm Flashcards
Conducting airway
Nose, pharynx, larynx (extra thoracic)
Trachea, bronchi, bronchioles (intrathoracic)
Respiratory zone
Terminal bronchi, alveoli, alveolar capillaries
Oxygenation
Factors that affect the muscles in the bronchi/bronchioles
-Transpulmonary pressure- keep smooth muscle areas open
-Smooth muscle- sympathetic (beta 2 receptors, relax smooth muscle and epi) and parasympathetic innerration, vagus nerve (acetylcholine causes contractions of bronchiolar smooth muscle and bronchoconstriction)
-Lung cells and endothelium=leukotrienes=constriction
-Histamine and substances from mast cells anaphylaxis and constriction
-Airway resistance-amp changes in diameters increase difficulty of breathing
Tidal volume TV
Volume of inspired and expired air with each normal breathe
Inspiratory reserve volume IRV
Max effort of air inspired after normal inspiration
Expiratory reserve volume ERV
Max effort of air expired after normal expiration
Residual volume
Air left in lungs at the end of expiratory reserve volume
Inspiratory capacity
Residual volume
Tidal vine plus Inspiratory reserve volume
75-120%
Functional residual capacity
Expiratory reserve volume plus residual volume
75-120%
Vital capacity
Inspiratory reserve volume plus tidal volume plus expiratory residual volume
(TV plus ERV is measurement)
Total lung capacity
Vital calcite plus residual volume
Max lung expansion.
80-120%
Forced expiratory volume
FEV and FEV1 (expired in one second)
80-120%
Normal PFT curve
Normal oval
Pressure necessary to get into lungs
Normal homeostasis
Increase in lung compliance in PFT
Wide oval curve
Increase pressure necessary for exhale
Obstructive disease-destruction of airway loss of elastin
COPD emphysema asthma
Decrease lung compliance curve in PFT
Compliance curve in side and narrow small curve
Increase pressure required to get air in and when air is in it’s usually less
Restrictive disease PNE, pulmonary edema, fibrosis
Intrathroacic pressure changes that result in air movement in and out of alveoli
-pleural pressure (between lining of pleura) negative -5 cm H20, inspiration (expansion) -7.5 cm H20 increase suction pulling lungs with ribs
-alveolar pressure- measure of respiratory tree, when glottis is open (atmospheric pressure is at 0) with chest expansion pressure decrease to 1cm H20 and air moves out, recoil-alveolar pressure increase to 1cm and air moves out
Transpulmonary- difference between pleural and alveolar pressure, elastic forces:PEEP, surfactant, and closed epiglottis
Pneumothorax
Breach of pleural spaces, atmospheric air enters and equalizes pressure to atmospheric at 0(-4 mm of Hg is lost) lungs cannot expand, air gets in but not out
S/s: SOB, tachypnea, deviated trachea, decreased breathe sounds on affected side, hyper resonance to percussion
Brain stem and breathing
Brain stem
Medulla-dorsal respiratory group (or neurons) for inspiration, ventral respiratory group (or neurons) for expiration
DRN-back and gloss pharyngeal nerve transmits signs from chemo baroreceptors which signals diaphragm and intercostal muscles
VRN basic autonomic rhythm of respiration, inactive during normal breathing, medullary rhythm of inspiration and expiration, fires during hypo ventilation and signals inspiration, which stimulates and muscle contraction for expiration
Pons
Pneumotaxic center responsible for respiratory rate and pattern
Pontine group modifies rhythm set by VRG
Chemoreceptors and breathing
-Center (near resp center)
Sense changes in pH of CSF, carbon dioxide crosses the BBB and H20, bicarbonate is formed, very sensitive to increase in CO2, and will change rate and depth of respiration, exceptions is in chronic conditions compensated acidosis by renal compensation
-Peripheral (aortic and carotid bodies)
Sense changes in O2 concentration decrease p02 and increase in RR
Lung intervention and breathing
-irritarion receptors (epithelium)
When lungs are irritated by inhalation of particulate matter-cough induced causes bronchospasms and increased RR
-stretch receptors
Smooth muscles stretch in bronchi, bronchioles, king parenchyma, signals DRN to switch off inspiration (prevents over inflation)
-pulmonary C fiber receptors (J receptors)
C fibers are sensitive to increases pulmonary capillary pressures (CHF) initiate shallow rapid breathing, laryngeal vasoconstriction, mucus secretion
Other mechanisms for breathing
Voluntary breathing with breathe techniques
CNS depression by brain injury or anesthesia