Pulmonary Flashcards
how is pH regulated?
exhalation of CO2
what three things do the lungs do to prepare air for entrance into the body?
warm to body temp, add water vapor, filter foreign material
the CO2 we exhale is a byproduct of what?
fat or sugar breakdown
cells use oxygen to make what?
ATP
what are the two roles of pleural fluid?
lubrication, chest wall sticking to lungs
the chest wall wants to pull the lung ____
outwards
the lung tissue wants to pull the lung ____
inwards
___ ____ is related to the inward pull from the lung tissue
elastic recoil
the ___ ___ of the secondary bronchi allow for contraction and closing
smooth mucle
what is the major structure of the secondary bronchi?
cartilage plate
what is the innermost layer of the secondary bronchi?
mucosa
the fluid layer in the cilia (pericilliary fluid) helps cilia do what?
stand straight
what part of the lung makes it a hostile environment?
cilia
the ____ zone is from the trachea to the bronchioles
conducting
does gas exchange occur in the conducting zone?
no
the ____ zone is the respiratory bronchioles to the alveolar sacs
respiratory
what is the primary surface for gas exchange?
alveolar sacs
what cells synthesize surfactant?
type 2 alveolar
what type of cells facilitate gas exchange by creating a shorter distance for gases to travel?
type 1 alveolar
what is the immune cell of the lungs?
alveolar macrophage
what are the 3 adaptations for gas exchange?
large surface area, thin diffusion barrier, stable gradients
why is the concentration of CO2 low in the lungs?
to allow CO2 to flow from blood into the lungs so it can be exhaled out
if you increase surface area, you ____ diffusion rate
increase
surfactant _____ pressure in smaller alveoli
increases
surfactant _____ surface tension in smaller alveoli
lowers
surfactant ____ the formation of H bonds between water molecules in the alveoli
decreases
surfactant breaks some of the H bonds in the thin layer of fluid which makes the lungs easier to _____
inflate (more compliant)
pressure inside of a bubble formed by a fluid film is the function of what two factors?
surface tension, radius
air moves from ___ alveoli to ___ alveoli
small, large
what law relates radius and surface tension?
Law of LaPlace
according to the Law of LaPlace, if two bubbles have the same surface tension, the ____ bubble will have higher pressure
smaller
why don’t small alveoli collapse into the big alveoli?
surfactant decreases surface tension, pressure is equalized
___ and ____ in the lungs increase elastic recoil
elastin, collagen
emphysema is a disease of ____ compliance
high
fibrosis is a disease of ___ compliance
low
do changes in airway diameters affect compliance or elastic recoil?
no
____ is related to the lungs ability to inhale
compliance
___ ____ is related to the lungs ability to exhale
elastic recoil
_____ Law is related to airway resistance
Poiseulille’s
resistance to flow is proportional to what two things?
length, viscosity (these remain constant)
resistance to flow is inverse to what factor?
radius
___ is the biggest factor in determining resistance to flow
radius
parasympathetics neurons, histamine, and leukotrienes lead to ____
bronchoconstriction
carbon dioxide and epinephrine lead to _____
bronchodilation
___ ___ ___ occurs to maximize gas exchange
ventilation perfusion matching
if ventilation _____ in a group of alveoli, PCO2 increases and PO2 decreases
decreases
if ventilation decreases in a group of alveoli, what happens to the blood flowing past?
does not get oxygenated
what is hypoxic vasoconstriction?
if group of alveoli is underventilated, arterioles leading to it constrict and divert to alveoli that are better ventilated
afterload ____ if you have too much vasoconstriction
increases
what long-term consequence occurs if there is too much vasoconstriction for too long?
right-sided heart failure
atmospheric and alveolar pressure at rest
equal at 760 mmHg
at rest, what is the intrapleural pressure?
substmospheric (O2 wants to move into lungs)
what happens to the alveolar pressure during inhalation?
decreases (subatmospheric) to make pressure gradient
what happens to the alveolar pressure during exhalation?
increases to make pressure gradient to push CO2 out of the lungs
what happens to the alveolar pressure during inhalation?
decreases
what happens to the alveolar pressure during exhalation?
increases
describe the pressures and volumes of atmospheric and alveolar at rest?
equal
what are the four characteristics that contribute to ease of inflation?
airway resistance (i.e. mouth vs nose breathing), surface tension, compliance, elastance
inadequate ____ decreases compliance
surfactant
what are the mechanical events of breathing?
contraction (inhalation) and relaxation (exhalation) of diaphragm and intercostal muscles
what event is caused by the mechanical event of breathing?
volume event (increase or decrease alveolar volume)
what is caused by the volume event of breathing?
pressure event (increase or decrease in alveolar pressure)
what is caused by the pressure event of breating?
development of a pressure gradient
air will move until it reaches what?
equilibrium
Boyle’s law relates what factors?
volume and pressure
breathing steps of a lung at rest
-no mechanical
-no volume change
-no pressure change
-no gradient formation
-no net air movement
breathing steps of inspiration
-diaphragm contracts
-increased volume
-decreased pressure
-gradient moves air into the lungs
-net movement of air into the lungs
breathing steps of exhalation
-diaphragm relaxes
-decreased volume
-increased pressure
-gradient moves air out of the lungs
-net movement of air out of the lungs
what is measured by spirometry?
air moving in and out of lungs
what is not measured by spirometry?
residual volume
___ ____ is the amount of air that you take in during a normal breath
tidal volume
___ ____ is the total amount of air moving in and out of the lungs per minute
minute ventilation
how is minute ventilation calculated?
tidal volume*respiratory rate
___ ____ is the amount of air that is available for gas exchange
alveolar ventilation
how is alveolar ventilation calculated?
(tidal volume-deadspace) * respiratory rate
what is respiratory rate?
breaths per minute
what is tidal volume?
mL/breath
volume versus capacity
volume is one, capacity is many
how do positive pressure ventilators work?
increase atmospheric pressure to create pressure gradient between lungs and air, air moves into lungs, then decrease atmospheric pressure to expel air from lungs
how many oxygen binding sites are on a hemoglobin?
4
what are the two means that O2 travels in the blood?
dissolved, bound to hemoglobin
what is the way that most of the O2 travels through blood?
bounds to hemoglobin in the RBC
___ _____ is the percentage of available binding spots on a hemoglobin occupied by O2
hemoglobin saturation
what is alveoli PO2 on the oxygen-hemoglobin binding curve?
100
what is the PO2 of a resting cell on the oxygen-hemoglobin binding curve?
40
what is happening to the bond of oxygen and hemoglobin in a leftward shift on the oxygen-hemoglobin binding curve?
increased bonding
what is happening to the bond of oxygen and hemoglobin in a rightward shift on the oxygen-hemoglobin binding curve?
release of bonds
what is more common, left or right shift on the oxygen-hemoglobin binding curve?
right (release)
direction of shift on oxygen-hemoglobin curve: high blood pH
left
direction of shift on oxygen-hemoglobin curve: low blood pH
right
direction of shift on oxygen-hemoglobin curve: low blood PCO2
left
direction of shift on oxygen-hemoglobin curve: high blood PCO2
right
direction of shift on oxygen-hemoglobin curve: low temperature
left
direction of shift on oxygen-hemoglobin curve: high temperature
right
direction of shift on oxygen-hemoglobin curve: no BPG
left
direction of shift on oxygen-hemoglobin curve: high BPG
right
BPG is a byproduct of what?
metabolism
what happens to O2 and CO2 during hypoventilation?
O2 falls, CO2 rises
what happens to O2 and CO2 during hyperventilation?
O2 rises, CO2 falls
what is the rate of normal ventilation?
4.2 L/min
what are the pressures of the alveoli and plasma prior to blood oxygenation?
100 mmHg in alveoli, 40 mmHg in plasma (resting cell)
what is bound content?
number of hemoglobin molecules * percent saturation
what is total content?
dissolved content + bound content (aka total amount of oxygen you have in blood)
respiratory control system is ____ feedback
negative
respiratory control system: controlled variable
PaO2, PaCO2
respiratory control system: sensor
chemoreceptors
respiratory control system: input
afferent nerves
respiratory control system: control center
respiratory control center (medulla, pons)
respiratory control system: output
somatic motor nerves
respiratory control system: effectors
intercostal muscles, diaphragm
respiratory control system: response
increased muscle contraction
respiratory control system: result of the negative feedback
increased PaO2 to normal
what do central chemoreceptors respond to?
changes in CO2 only
what do peripheral chemoreceptors respond to?
changes in CO2, O2, pH
where are the medulla and pons located?
brainstem
which intercostals are related to inspiration?
external
what intercostals are related to expiration?
internal
the ___ fine tunes control of breathing
pons
the ___ is the major control center for breathing
medulla
part of the medulla responsible for inspiratory (quiet) respiration
dorsal respiratory group (DRG)
part of the medulla responsible for expiratory (forceful) ventilation
ventral respiratory group (VRG)
part of the medulla responsible for pacemaking via spontaneous depolarization
pre-botzinger complex
what is the pre-botzinger complex a part of?
the ventral respiratory group (VRG)
the amount of oxygen that can bind to hemoglobin is determined by what?
the amount of oxygen in the dissolved
what two factors influence the total number of binding sites for oxygen on hemoglobin?
hemoglobin content per RBC, number of RBCs (i.e. anemic, bleeding)
what is the determining factor of percent saturation of hemoglobin?
how much/quality of air to the alveolous
_____ content is determined by how and what you breath
dissolved
____ content is dissolved plus bound
total
____ content is determined by the number of RBCs and number of binding sites
bound
what determines saturation?
percent of binding sites occupied
does saturation depend on amount of hemoglobin/RBCs?
no
flow of CO2 out of the body:
cells, blood, heart, lungs
7% of CO2 is where?
dissolved in plasma
23% of CO2 is where?
bound to hemoglobin
70% of CO2 undergoes what?
conversion into bicarbonate and then dissolved into the plasma
why is 70% of CO2 converted into bicarbonate (HCO3-)?
bicarbonate is more soluble
what is the weak acid made when CO2 and H2O come together?
H2CO3 (carbonic acid)
what is the biproduct of H2CO3 (weak, carbonic acid) breaking down?
H+, HCO3- (bicarbonate)
what is the resting cell CO2 level?
46 mmHg
where does bicarbonate go once it enters the dissolved/plasma?
lungs
why is bicarbonate transported to the lungs after diffusing into the plasma/dissolved?
maintain neutrality
what is the unique ability of carbonic anhydrase?
catalyzes reaction in both directions
what are the two locations of baroreceptors?
carotid, aortic arch
____ _____ ______ is the air that can be forcefully inhaled after a normal breath
inspiratory reserve volume
____ _____ ____ is the air that can be forcefully exhaled after a normal breath
expiratory reserve volume
__ ____ is the maximum air remaining in the lungs after maximal exhalation
residual volume
__ ___ ____ is the expiratory reserve volume and the residual volume, i.e. what is left in the lungs after a normal exhale
functional residual capacity
what makes up the vital capacity?
IRV, TV, ERV
what makes up the inspiratory capacity?
IRV, TV
what makes up the total lung capacity?
everything combined: IRV, TV, ERV, RV
how do you calculate residual volume?
total lung capacity (TLC) - vital capacity (VC)
is ATP consumed during inhalation or exhalation?
inhalation
central chemoreceptors sense changes to CO2 in the ____ component
dissolved
what activates the central chemoreceptor with CO2 is high?
release of H+ ions
why can’t H+ ions from the cerebral capillary enter the CSF?
is charged so needs a channel
what are the two locations of peripheral chemoreceptors?
aortic arch, carotid body
steps of peripheral chemoreceptor reaction to low PO2
-K channels close
-cell depolarizes
-voltage-gated Ca channels open
-neurotransmitter released
what stimulates increased ventilation?
decreased O2, increased CO2, increased pH due to the increased CO2
what is normal plasma PO2?
100 mmHg
at what pressure of O2 does increased ventilation occur?
around 60
CO2 is ___ to pressure changes:
sensitive
what are the 3 ways to blood dope?
-injections of EPO
-injections of synthetic oxygen carriers
-transfusions with whole blood
what is the goal of blood doping?
increase RBC to increase bound
why is CO the silent killer?
body has no receptors for CO, does not know there is an issue
why does CO decrease oxygen levels?
outcompetes oxygen for binding spots on hemoglobin
