5.3 Flashcards
what is lung compliance
the ability for the lung to streatch, most important when inhaling
Lower lung compliance
the harder it is to expand the lngs (inhalation)
people with low lung compliance breath shallowly and rapidly
High ling compluance
indicates that the lung stretch easily and easier to breathe
What is lung elastance
degree and or speed of return to resting volume after lung is stretched
luw lung elastance
the lung does not return to resting volume passively
- expiration must be active not passive
What is airway resistance determined by
primiraly by airway diameter 8Ln/pi r^4
work neeed to overcome resistance to streatch and airway resistance what lower, but what factors can affect it
airway resistance work lower
mucus accumulation from allergies or infections can greatly increase resistance of the airway
what can affect bronchiole diameter
nervous system, hormones and paracrines
CO2 causes what to the bronchiles
bronchodilation (bigger)
what causes bronchoconstriction (small), difficulty breathing
histamine released in response to tissue damage or allergic reactions causes broncho constriction
and several allergic reactions
what does the nueral control of bronchioles (parasympathetic and sympathetic(
Prinarily by parasympathetic neurons that cause broncho constricriction
- reflex designed to protecct lower respirotory tract from inhaled irrants
No signifact sympathatic pathway
How is hormonal control of bronchiles done and what it do
done priarily via circulating epinephrine
- through B2 receptors in smooth muscle of bronchiles - relaxes muscle to dilute bronchioles
- used as a treatment for asthma
why is pulmonary function assesed
to determine the amount of air a person moves during quiet breathing and maximal breathing effort
what is used to measure pulmonary function and how does it work
spirometer- instrument that measures movement of air during breathing, and allows for diagnosis of many diseases
what are the 4 lung volumes
tidal volume, inspiratory reserve volume, expiration reserve volume, residual volume
tidal volume
amount of air moved in a single normal inspiration or expiration
inspiratory reserve volume
maximum amount of air that can be inspired above tidal volume
expiratory reserve volume
amount of air that can be exhaled after a normal expiration
residual volume
amount of air ledt in the lungs after maximal expiration
what is the sum of wo or more lung volumes and what does it reprecent
capacity
vital capacity
- the maximum amount of air that cen be voluntarily moved
vc = IRV + ERV + VT
total lung capacity - TLC
TLC = Vital capacity + Residual volume
what is minute volume and how to calculate it
estimate the effictiveness of breathing by measuring the total pulmonary ventilation
- MV = Vt (mL/breath) x respiratory rate (breaths/min)
wha are dead spaces located in the airays
no gas exchange, air in trachea, bronchi and bronchioles does not participate in gas exchange
alveolar volume = Vt - dead space
effectiveness of ventilation is determined by what and why
the rate and depth of breathing, bc of the dead space, increase in depth of breathing is most important
Alveolar ventilation what is it and what it do and eqn
the amount of air that reaches the alveoli each minute
a more accurate indicator of efficiency of venttilation
alveolar ventilation = ventilation rate x alveolar volume
what is ventilation matched to and why
matched to alvoelar blood flow - the body attempts to match air flow and blood floow to maximize gas exchange in the capillary beds that surround the alveoli
what does alterations inblood flow in the lungs depend on
primarily local control exerted by o2 levels in the interstitial fluid around the arteriale surrounding the alvoeli
what causes vasodilation in the arteriole
increases in tissue PO2
if ventilation of alveoli in an are of the lung decreaasses what will happen
the tissue O2 in that area also decreases
