Respiratory Flashcards
where does gas exchange occur?
- air to alveoli to blood
- blood to tissues
if a child inhales a small object where will it most likely end up?
Left lung (longer and more upright)
where does gas exchange in the lungs take place?
alveoli
if someone has pulmonary edema, where does the fluid collect
initially in interstitial space (not a lot of space here)
then moves into alveoli
T/F: air can move from one alveolus to a neighboring alveolus?
TRUE, through pores
where is the parietal pleura?
lining the thoracic cavity wall, mediastinum, and diaphragm
inhaling _______ the thoracic wall which _______ the lungs to ________ pressure in the lungs
- expands
- expands
- decreases
where is the visceral pleura?
adhering to the lungs
What is in the space between the parietal and visceral pleura?
fluid, which allows for movement to be smooth with reduced friction
what is pleurisy?
a condition when the pleural cavity becomes infected, causing the layers to move over each other more roughly and making breathing more difficult
How do we create a pressure gradient to move gases into and out our lungs?
by changing the volume of the thoracic cavities and pleural cavities we can alter the pressure in those spaces
define tidal volume
amt of air moving into and out of the lungs; quiet breathing
define respiratory rate (RR)
number of breaths taken in one minute
define inspiratory reserve volume (IRV)
amt of air that can be forcibly inhaled AFTER a TV
define expiratory reserve volume (ERV)
amt of air that can be forciby exhaled AFTER a TV
Define forced vital capacity (FVC)
amt of air that can be forcibly exhaled after a max inhalation
also called vital capacity (VC).
define residual volume
what remains in the lungs after a max expiration is done
define total lung capacity (TLC)
amt of gas in the lungs following a max inspiration
what happens if a patient has decrease lung compliance?
it decreases their IRV b/c their lungs can’t expand as well as a normal person
what is compliance?
refers to the stretchability or elasticity of the lungs
why doesn’t the surface tension of the water in the alveoli dramatically reduce compliance normally?
cells secrete surfactant which helps reduce surface tension and allow the lungs to be more compliant and prevent complete collapse of the lungs when we exhale
T/F: the partial pressure of atmospheric oxgyen remains the same regardless of altitude
FALSE, the fraction of oxygen remains the same, but the partial pressure changes
How is gas transported in the blood?
- dissolved in blood
- attached to hemglobin
- carried in the form of bicarbonate ion
how are harmful particles filtered out in the respiratory system?
- large particles are filtered out in the nose
- smaller particles are trapped in the mucus of the upper airways
- macrophages (immune cells) are in the endothelium of the alveoli
what primarily controls ventilation?
the level of PCO2 in blood
increased CO2 in the blood will result in _______ H+
increased
increased H+ results in _______
acidosis
is too much CO2 is blown off, H+ ion concentration will _________ resulting in ________
decrease
alkalosis
if a pt. is hyperventilatin they will go into ______
respiratory alkalosis and can pass out
is a patient has emphysema they are __________
retaining too much CO2 and the blood becomes acidic
what measures H+ and CO2 in the blood?
peripheral chemoreceptors
central chemoreceptors
where are peripheral chemoreceptors?
aortic bodies
carotid bodies
where are central chemoreceptors?
medulla of the brain stem
how is oxygen transported in the blood?
- dissolved in blood
- most is bound to hemoglobin
how does high/low PO2 impact loading of O2 onto/from hemoglobin?
- High PO2 = more loading O2 onto hemoglobin
- Low PO2 = more unloading of O2 from hemoglobin
hemoglobin’s afinity for O2 ________ as successive O2 molecules bind
increases
hemoglobin wants to bind more O2
what is the hypopharynx?
connects the larynx to the esophagus
T/F: people can live their whole life with only 1 lung?
TRUE, they will have a reduced exercise capacity though
what is the pleural pressure?
the pressure in the pleural space (betwen the parietal and visceral pleura)
What is the transpulmonary pressure?
the difference between the alveolar pressure and the pleural pressure
T/F: inhalation is a passive process
FALSE, it requires a lot of energy throughout the whole process
why do the lungs expand when the chest expands?
due to the adhesive force of the pleural fluid in between the pariteal and visceral pleura, the expansion of the thoracic cavity forces the lungs to stretch and expand as well
T/F: expiration is an energy expensive process?
FALSE, it is fairly passive
what is inward elastic recoil at the lungs?
the rebound of the lungs after having been stretched by inhalation
what contributes to the inward elastic recoil of the lungs?
- surface tension of water in the alveoli
- elastin in the connective tissues of the lung
why don’t lungs the lung collapse between breaths?
the opposing recoil forces (inward and outward elastic recoil) are equalized at the end of exhalation
What is outward elastic recoil?
a property of the chest wall
causes an upward movement of the thoracic wall
what factors decrease lung compliance?
- fibrosis (scarring) = reduces elasticity
- increased surface tension of the water layer on the alveolar surface
what portion of the gas being transported in blood contributes to the partial pressure?
the dissolved portion
name one benefit to a low pressure system within pulmonary circulation?
lower risk of pulmonary edema
when the partial pressure of O2 is low within an alveoli, how do the pulmonary arterioles react?
they constrict to shunt blood elsewhere to alveoli that have a higher partial pressure
describe the relationship of blood flow to alevolar partial pressure of O2
blood flow to the alveoli increases when they are well ventilated (increased PO2)
and decreases when they are not
why is there a unique ventilation/perfusion blood flow pattern in the lungs?
ensures that there is a better matching of ventilation (air flow) to perfusion (blood flow) insuring maximal transfer of available oxygen
why is there less blood flow to the apex of the lung compared to the base?
- effect of gravity pulling the blood down
- low pressure system of lungs reduces ability of blood to move “uphill”
T/F: upright positioning will improve V/Q ratio?
TRUE
In most circumstances ______ is a signal for ventilation
CO2
In patients with cervical spine trauma and emphysema, how would you expect their blood pH to look?
more acidic –> trouble exhaling = increased CO2
chemoreceptors in the medulla are sensitive to ______
H+ ions, but they can’t cross the BBB
how can the medulla respond to H+ ions if they can’t cross the BBB?
CO2 can cross over
once it does it is converted to carbonic acid
this then becomes bicarbonate and a H+ which the medulla then responds too
T/F: carotid and aortic bodies are stimulated by decreases in blood pH independent of Pa CO2 status?
TRUE
