Respiratory Flashcards
Equation for ventilation (flow)
P(alv) - P(atm) / resistance
Equation for transpulmonary pressure
P(alv) - P(ip)
Shifts Hgb dissociation curve to the RIGHT
Increased CO2
Increased Hydrogen ions
Hyperthermia
Increased 2,3-DPG
Shifts Hgb dissociation curve to the LEFT
Decreased CO2 (Hgb wants to pick up O2)
Decreased Hydrogen ions
Hypothermia
Decreased 2,3-DPG
decreased shifts to left
What is the first airway that doesn’t contain cartilages?
broncioles
goblet cells
secrete mucus to maintain moisture and trap pathogens
basal cells
differentiate into other cell types to restore a healthy epithelial cell layer
cilia cells
move back and forth carrying mucus up and out of the respiratory tract
type II alveolar cell (pneumocyte)
large and round
secrete surfactant
pleural space
between the lung and chest wall
visceral pleura: inner layer against lung
parietal pleura: outer layer against chest wall
functions of the pleura
-mechanical support of the lung
-allows the lung to move relative to the chest wall
-an area for edema to escape the lung
Boyle’s Law
pressure increases when volume decreases
P1V1 = P2V2
transmural pressure
transpulmonary and chest wall pressures
transpulmonary pressure
net distending pressure applied to the lung by contraction of the inspiratory muscles or by positive-pressure ventilation
-holds lungs open
chest wall pressure
interpleural pressure minus atmosphere pressure
-holds chest wall in
inspiration
muscle: diaphragm & some accessory muscles
negative pressure
active process
expiration
muscle: abdominal muscles
positive pressure
passive process
compliance
stiffness of the lung and chest wall
= change in lung volume for a given change in transpulmonary pressure
normal: ~100 mL/cmH20
low compliance = increased stiffness
resistance
diameter of the airways
rate at which air flows through bronchial tree depends on size of airways
small change in radius = large change in resistance
surface tension of alveoli
water lining of the alveoli creates surface tension
requires a lot of pressure to overcome
surfactant
acts as a detergent and breaks the surface tension
prevents complete collapse of alveoli during exhalation
LaPlace’s Law
wall tension of a hollow sphere is proportional to both the pressure of its contents and its radius
asthma
chronic inflammation of airways that leads to hyperresponsiveness of the smooth muscle increasing airway resistance
-inflamed, narrowed airways
COPD
collapsed airways and damaged alveoli
-FEV1/FVC <70%
tidal volume
amount of air inhaled or exhaled in one breath
~500 mL
inspiratory reserve volume
the extra air we breathe in with max effort after a normal breath
~3L
expiratory reserve volume
the extra air we breathe out with max effort after a normal exhalation
~1.2L
residual volume
the air remaining in the lungs after forcing all the air out
~1.2L
vital capacity
the total volume of air we can breath in and out
inspiratory reserve volume + tidal volume + expiratory reserve volume
functional residual capacity
the amount of air in the lungs after a normal breath is exhaled
expiratory reserve volume + residual volume
inspiratory capacity
the largest amount of air we can inhale after normal exhalation
tidal volume + inspiratory reserve volume
total lung capacity
the max amount of air that can be in the lungs
all the volumes added together
dead space
volume of inspired air that does not take part in gas exchange
anatomical dead space
dead space associated with lung anatomy
~150 mL or 2 mL/kg
alveolar dead space
usually associated with lung disease
fresh inspired air not used for gas exchange despite reaching alveoli
alveolar ventilation
(tidal volume - anatomical dead space) / RR
Dalton’s Law of Partial Pressure
in a mixture of gases, the pressure exerted by each gas is the same as that which it would exert if it alone occupied the container
Henry’s Law
the amount of gas dissolved will be directly proportional to the partial pressure of the gas with which the liquid is in equilibrium
intrapulmonary shunt
blood passes through the lungs but fails to take part in gas exchange
oxygen transportation
-4 heme attached to 4 polypeptides make a Hgb
-each Heme contains 1 iron which binds to O2
oxygenation
how effectively oxygen enters the blood and saturates hemoglobin
ventilation
how effectively CO2 is eliminated from the blood
arteriole response to hypoxia
systemic: dilate
pulmonary: constrict
hypoxic pulmonary vasoconstriction
pulmonary blood flow is controlled in the fetus and by which local lung perfusion is matched to ventilation in the adult
type 1 respiratory failure
hypoxic
tachypnea, brady/tachycardia, HTN, confusion/delirium, anxiety/restlessness
CO2 transport
combines with water in the RBC to form H2CO3 and transformed in the lungs back to CO2
type 2 respiratory failure
hypercapnia
tachypnea, tachycardia, HTN, HA, altered mental status, papilledema
control of respiration
chemoreceptors in the brain: pH of CSF
chemoreceptors in the aortic/carotid bodies: CO2
oxygen receptor in the aortic/carotid bodies: O2
peripheral receptors: pH
acclimatization to hypoxia
hypoxic hypoxia
chronic exposure: higher thana normal hematocrit
