respiratory Flashcards
what are some of the non-respiratory functions that the respiratory system carries out?
- provides a route for water loss and heat elimination
- enhances venous return
- contributes to the maintenance of normal acid-base blood balance
- enables vocalization
- defends against inhaled foreign matter
- modifies, activates and inactivates materials passing through the circulatory system
what are the 4 properties of gasses?
daltons law
boyles law
gaseous movement law
mixed gases behaviour law
what is daltons law?
the total pressure of a mixture is the sum of each. each part is known as partial pressure
what is boyles law?
the volume of a gas is inversely proportional to the pressure exerted on the container.
P1V1=P2V2
- decreasing the volume of a container increases the number of particle collisions and thus increases the pressure
what is the movement of gases law?
gases move from high pressure areas to low pressure areas
what is the behaviour of mixed gases?
mixed gases behave like pure gases
78% of air is composed of _______
20.9% of air is composed of _____
1.1% of air is composed of _____
Nitrogen
oxygen
water, carbon dioxide and nobel gases
average total atomspheric pressure is usually around ____
760 mm Hg
if total atmospheric pressure was 760 mm Hg, what would the partial pressure of nitrogen and oxygen be?
nitrogen: 593 mm Hg
oxygen: 159 mm hg
as the temperature rises and the humidity increases, describe the change in partial pressures of oxygen and nitrogen;
the partial pressures would decrease because there is an addition of water vapour in the air. this does not change the total pressure, just the partial pressures.
atomspheric pressure describes the height of the air column between the ____ all the way to space
top of your head
as you increase in altitude, you shrink the space from the top of your head to space, what affect does this have on the partial pressure of oxygen?
the partial pressure of oxygen would decrease each time the altitude increases
what are the 2 types of respiration?
cellular respiration
external respiration
what is cellular respiration?
the breakdown of energy stores into CO2. it involves glycolysis, krebs and oxidative phosphorylation
what is external respiration?
the exchange of gases between the external environment and the cells of the body
_____ respiration SUPPORTS ___ respiration
external respiration suppors cellular respiration :)
describe the 4 steps of external respiration;
1: ventilation/gas exchange between atmosphere and air sacs (alveoli) in the lungs
2: exchange of CO2 and O2 between air in alveoli and blood
3: transport of O2 and CO2 between lungs and tissues
4: exchange of O2 and CO2 between blood and tissues
describe lung development:
the tissues surround the bud of a lung consist of the perimordial foregut, ectoderm and endoderm.
at 3 weeks gestation the lung bud begins to grow and form between the endoderm and the forgut.
after 3 weeks the body begins to produce, FGF-10, retionic acid, beta-catenin and shh which help to further grow the lung.
at 4 weeks gestation, the lung bud develops perimordial lung buds that push on the ectoderm.
at 6 months, the bronchiole tree is formed
what are the hormones involved in early development of the lungs? (3 weeks)
FGF-10, retinoic acid, beta-catenin and shh
what are the hormones involved in branching at 4 weeks?
FGF-10 and spry
what do spry and FGF-10 do?
spry inhibits growth but FGF-10 increases it. thus, this causes 2 tubes to be made. they continuously sprout like this approx 23 more times.
what hormone does alveolar development require?
FGF-3&4
what hormones help to develop the lung tissues (not just the bronchiole tree)
BMP-4, HOX, TGF-beta
how will an absence of shh(cre)-B-catenin(flox) affect the development of pulmonary vasculature?
the lung buds will not form but the bronchiole tree will develop.
this helps to show that pulmonary vasculature and bronchiole tree are not linked.
what is the pleural sac?
a double layered membrane that has been left over from the endoderm that is filled with fluid.
the embryonic lung produces most of the ____ mid-gestation with decreasing contribution as the kidneys mature
amniotic fluid
airway/lung development requires the lungs to be ____ with ____
inflated
with liquid
why are the lungs required to be inflated during gestation?
the fluid keeps tubes open so they do not close and seal by matrix proteins. the liquid is vital for internal pressurization
what must happen at the time of birth for babies to be able to breath?
the liquid that filled the airways must be rapidly absorbed
at what stage in gestation does the ability to reabsorb liquid develop?
2-3 weeks before birth
why do preemie babies struggle to breath on their own?
they haven’t developed the ability to remove the liquid and deal with air by the time of their early birth
what pieces of the bronchial tree compile the conducting system?
trachea
primary bronchi
smaller bronchi
what pieces of the bronchial tree compile the exchange surface?
bronchioles
alveoli
describe the anatomy of the LUNG from out to in;
throacic wall
parietal pleura
parietal cavity
pleural sac
visceral pleura
describe the what body parts compose the respiratory pathway;
nasal cavity and tongue
pharynx
vocal chords
larynx/esophagus
trachea
bronchus
lungs
diaphragm
give a small description of the nasal cavity;
has a special bone called the turbinate
it meshes with the mucus membrane
give a small description of the tongue;
buccal can allow larger quantity of air ro be moved
works with food and air
during swallowing, which part of the respiratory pathway works to close off the larynx?
the vocal chords
give a small description of the trechea;
cartilage holds it open so it doesn’t collapse
males have a thickening of the trechea known as the adams apple
what are the components of the upper respiratory system?
nasal cavity
tongue
oharynx
vocal chords
larynx
esophagus
what are the components of the lower respiratory system?
trachea
bronchus
lungs
diaphragm
describe the anatomy of the lung from top to bottom;
apex = top
superior lobe
inferior lobe
base
- the left lung contains the cardiac notch where the heart rests
the superior lobe can be called as something else, what is it?
pulmonary dead space
why is the superior lobe known as the pulmonary dead space?
the bottom 1/3 of the lungs profuses better with blood
the top 2/3 arent ventilated as well as the bottom
however, this dead space can be activated to generate more air
describe the layers of the inside of the nose;
mucus layer
saline layer
cilia
soblet cell
columnar epithelial cell
basement membrane
what is the role of the mucus layer in the nose?
traps inhaled particles such as dust
what is the role of the saline layer in the nose?
allows cilia to push mucus toward pharynx
what is the role of the gobelt cells in the nose?
secretes mucus
why cant CF patients remove mucus?
they only have a single chloride channel
do cilia move individually or synchronized?
synchronized
describe the structure of the lung lobule;
bronchiole and branch of pulmonary artery
smooth muscle
brachial artery, nerve and vein
elastic fibers
capillary beds
alveoli
lymphatic vessel
branch of pulmonary vein
each cluster of alveoli is surrounded by ____ and a network of _____
elastic fibers
capillaries
inside of the alveolar sac there are pores of ____
kohn
what is the name of the only vein that carries oxygenated blood?
pulmonary vein
what is the name of the only artery that carries deoxygenated blood?
pulmonary artery
describe the structure of the alveolus;
the reside in ISF
Type 1 alveolar cell (structure)
type 2 alveolar cell ( stem cell)
alveolar fluid lining with surfactant
alveolar macrophage
lungs are ___% efficient at capturing oxygen
80
what is the distance between blood and air?
0.5 micrometers
why are erythrocytes flat?
an RBC can only fit through one way to facilitate gas exchange
why is it bad that CF patients lack a chloride pump?
the chloride pump is used by lysosomes to create acidity to kill pathogens, therefore, CF patients can’t kill invading pathogens effeciently
what are the 2 muscles that are only engaged for large inhilations to activate the dead space?
sterno-cleido mastoids
scalenes
what are the muscles of inhalation?
external intercostals
diaphragm
what are the muscles of exhalation?
internal intercostals
abdominal muscles
what is the bucket handle breathing movement?
when you breath in, the ribs move upward, increasing the lateral dimension of the rib cage
what is the pump handle breathing movement?
when you breath in, the ribs move upward, which increases the front to back distance by pushing out the sternum at the same time the diaphragm is contracting
moving the ribs and moving the diaphragm also indirectly moves the lungs via ___
the connection with the fluid space
what is the purpose of the parietal cavity filled with intrapleural fluid?
allows membranes to slide past eachother but allows them to be linked so if you pull one you pull the other
describe the sequence of muscle movements during inhalation;
1: elevation of ribs causes sternum to move up and out which increases front-back dimensions of the thoracic cavity
2: contractions of external intercostal muscles causes elevation of ribs which causes side-side dimensions
3: lowering of diaphragm on contraction increases vertical dimensions
4: to further increase volume, accessory muscles lift collar bone, connected to sternum, increasing volume of thoracic cavity
this is why inhalation requires energy
the thoracic wall, pleural cavity and alveoli create a pressure gradient known as the _____
transmural pressure gradient
how is the transmural pressure gradient created?
by a closed system with 1 immovable/fixed object and 1 elastic energy
what are the relative numbers of the transmural pressure gradient?
760 - thoracic wall
756 - pleaural cavity
760 - lungs
why is the pressure in the pleural cavity more negative?
the cavity created a greater negative pressure so the lungs pull harder to keep their position against thne ribs pulling
during inhalation, how much do the normal resting pressures change?
thoracic 760 – 759
pleural 756 – 754
lung 760 – 759
during exhalation, how much do normal resting pressures change?
thoracic 760 – 761
pleural 756 – 756
lungs 760 – 761
the first 150 mL of air you breath into your lungs is know as ___ air
stale
what is stale air?
air that is depleted in oxygen
air that is remaining from your previous breath
describe the process of air exchange;
1: at the end of inhalation, the dead space is filled with 150 mL of fresh air
2: as you exhale, you release 500 mL of air (tidal volume). this is not a full breath. 150 mL of this exhale remains in the dead space and 350 mL leaves the alveoli.
3: at the end of exhalation the dead space is filled with stale air
4: inhalation of a fresh 500 mL occurs, however the first 150 mL is the stale air from the dead space. only 350 mL is fresh air
what are the 4 lung volumes?
residual volume
expiratory reserve volume
tidal volume
inhalation residual volume
what is residual volume?
the volume of air remaining in the lungs after maximum forceful expiration
what is expiratory reserve volume?
The extra volume of air that can be expired with maximum effort beyond the level reached at the end of a normal, quiet expiration
what is tidal volume?
the amount of air that moves in or out of the lungs with each respiratory cycle
what is inhalation reserve volume?
the amount of air a person can inhale forcefully after normal tidal volume inspiration
what is inhalation capacity?
the maximum volume of air that can be inhaled following a resting state
what is vital capacity?
the maximum amount of air a person can expel from the lungs after a maximum inhalation.
what is functional residual capacity?
the volume of air present in the lungs at the end of passive expiration
why do men typically have larger pulmonary volumes?
because they have larger rib cages and thus a larger volume to fill
reserve volumes are only achieved when ____
needed/necessary
a pneumothorax or collapsed lung occurs when there is a leakage of air into the pleural space, what happens to the lungs normal abilities?
if the sealed pleural cavity is opened to the atmosphere, air will flow in causing the lung to collapse to its unstretched size. the ribcage expands due to the air inside the space but the long has lost its residual volume.
the pressure inside the lung would now be equivalent to the atmospheric pressure
if you puncture a lung, will both be affected?
no, both lungs are encased in their own pleural sacs so that if one is damaged the other can work overtime to help curve the effects
only ___ % of energy intake is used to breath
3
during ideopathic pulmonary fibrosis, the elastic fibers of the pulmonary system have been replaced with collagen. this increases the use of energy to ___% to breath.
30
FGF-3 and make ____________ which is built to allow easy movement
elastin fiber
if the lung is stretched it reboundss easily. This effect is known as ___-
elastic recoil
what is compliance?
the effort or work required to stretch or distend the lungs.
a normal elastin lung is _____ compliant
highly
pulmonary elastic behaviour depends on _____ and ______
elastic fibers
alveorlar surface tension
how is the alveolar surface tension determined?
by the thin liquid film that lines the outside of each alveolus
the surfactant lining the alveolus allows resistance to ____ and squeezes the ____ to produce recoil
expiration
alveolus
the surfactant on the outside is known as a tension balancer, why?
it prevents the alveoli from collapsing from the surface tension
what type of cells produce surfactant?
type 2
what is the composition of surfactant?
85% phospholipids
5% cholesterol
10% surfactant proteins
what are the names of the surfactant proteins?
A B C D
what do surfactant proteins A and D do?
funti9on with macrophages in pathogen clearance.
assist by opsonizing pathogens for phagocytosis
what do surfactant proteins B and C do?
interact with phospholipids to decrease the surface tension and spread liquid over the alveolar surface better.
describe the law of La Place;
- smaller alveoli are better at gas exchange, they generate greater tension.
- if the smaller alveoli were to collapse it would push all its air into the bigger alveoli
- not all alveoli are created equally in size
- a smaller alveoli would have a greater pressure than a bigger alveoli
- surfactant changes the surface tension so that the alveoli of varrying sizes would be equal in pressure.
why is surfactant needed for inhalation?
because otherwise the water pressure would be too hard to overcome
an obstructive lung would change what graphical values?
FEV1 - would be smaller
VC - would be smaller
for obstructive lungs it is harder to exhale air, but inhalation remains elatively normal
a restricture lung would change what graphical values?
FEV and VC would significantly decrease
inhalation would be significantly decreased
for restrictive lungs there is a decrease in the total volume of air that the lungs are able to hold
resistance in the lungs is proportional to:
viscosity x length / r^4
what is the equation to calculate flow rate in the repsiratory system?
change in pressure / resistance
because the difference between atmospheric and intra-alveolar pressures is greater, the air flow is ____
greater
increasing the resistance to airflow decrease the air flow as a function of the raidus would mean a 2 fold decrease in radius causes _____
a 16 fold increase in the resistance
what is the major determinant of resistance?
the ANS
the ANS controls;
contractioon of the smooth muscle in the walls of the bronchioles changing the radii
sympathetic stimulation releases ____ which causes _____
epinepherine
bronchodialation
parasympathetic stimulation releases ____ which causes ____
histamine
vasoconstriction
what is emphysema?
desctruction of alveoli reduces surface area for gas exchange.
alveolar sacs become 1 with low partial pressure of oxygen in the blood
what is fibrotic lung disease?
thickened alveolar membrane slows gas exchange. loss of lung compliance may decrease alveolar ventilation.
causes low partial pressure of oxygen in te blood
what is pulmonary edema?
fluid in the interstitial space increases the diffusion distance. arterial partial pressure of carbon dioxide may be normal due to higher solubility in water.
there is a normal exchange surface ( alveolar membrane is normal)
the partial pressure of oxygen is low in the blood
what is asthma?
increased airway resistance decreases airway ventilation
the bronchioles leading to the alveoli are constricted
causes low partial pressure of oxygen in both the blood and alveoli
a tissue cell has ___ Oxygen and ____ carbon dioxide
low oxygen
high carbon dioxide
the alveoli has ___ oxygen and ____ carbon dioxide
high oxygen
low carbon dioxide
what is ratio of oxygen to carbon dioxide in the alveoli?
100 O: 40 C
what is the ratio of oxygen to carbon dioxide in inhalation (pulmonary – systemic)?
100 O: 40 C
what is the ratio of oxygen to carbon dioxide in a tissue cell?
40 O: 46 C
what is the ratio of oxygen to carbon dioxide in exhalation (systemic – pulmonary)?
40 O: 46 C
what is the O2 partial pressure gradient from alveoli to blood?
60 mmHg (100-40)
what is the CO2 partial pressure gradient from blood to alveoli?
6 mmHg (46-40)
what is the O2 partial pressure gradient from tissue cell to blood?
6 mmHg (46-40)
what is the CO2 partial pressure gradient from tissue cell to blood?
6 mmHg (46-40)
what is the normal oxygen diffusion rate?
21 mL/min/mmHg
what is a rate of oxygen diffusion characteristic of exercise?
65 mL/min/mmHg
what is the effect of pH on normal oxygen exchange?
a lower pH (more acidic) causes a rightward shift
BOHR effect
what is the effect of temperature on normal exygen exchange?
higher temperatures cause a rightward shift
what is the effcet of CO2 on normal oxygen exchange?
higher CO2 concentration shifts rightward
HALDANE effect
what is the effect of DPG on normal oxygen exchange?
adding more DPG causes a rightward shift
what is the difference between fetal and maternal hemoglobin?
fetal hemoglobin has a higher concentration of CO2
what is hypoxic hypoxia and what are typical causes?
low arterial oxygen
typically caused by high altitude, alveolar hypoventilation, decreased lung capacity, abnormal ventilation-perfusion ratio
what is anemic hypoxia and what are typical causes?
decreased total amount of O2 bound to hemoglobin
typically caused by blood loss, anemia, CO poisoning (hemoglobin loves CO)
what is ischemic hypoxia and what are typical causes?
reduced blood flow
typically caused by heart failure, shock, thrombosis
what is histotoxic hypoxia and what are typical causes?
failure of cells to use O2 because cells have been poisoned
typically caused by cyanide or other metabolic poisons
tottal arterial O2 content can go to two different places, what are they?
dissolved in plasma
bound to hemoglobin
oxygen dissolved in plasma helps to determine the _______ of hemoglobin
% saturati9on
the amount of oxygen dissolved in plasma is determined by;
- composition of inhaled air
- alveolar ventilation (rate and depth of breathing, airway resistance, lung compliance)
- oxygen diffusion between alveoli and blood (SA and diffusion distance – thickness and ISF concentration)
- adequate perfusion of alveoli
the amount of oxygen bound to hemoglobin is determined by;
the % saturation x the total number of binding sites
the % saturation of hemoglobin is determined by;
Pco2
pH
temperature
DPG
the total number of binding sites for hemoglobin is determined by;
Hemoglobin content per red blood cell
number of red blood cells
a low pH can cause
acidosis
a high pH can cause
alkalosis
what is a normal range of pH for venous and arterial blood?
7.35-7.45
what is the ratio of CO2 to HCO3?
1:20
which ratio has a greater response ability to adapt;
1:20
2:40?
2:40
in the venous blood, ___% of CO2 is dissolved, ___% is bound to hemoglobin and ____% is converted to HCO3 inside an RBC and transported to plasma
7
23
70
what is hyperoxia?
an above normal arterial partial pressure of oxygen
what is hypercapnia?
an excess of CO2 in the blood caused by hypoventilation (respiratory acidosis)
what is hypocapnia?
below normal arterial level of CO2 in the blood due to hyperventilation (respiratory alkalosis)
what is hypernea?
an increased need for oxygen delivery and CO2 elimination (i.e. during exercise)
what is the haldane effect?
deoxygenated hemoglobin has an increased affinity to CO2.
conversely in a high CO2 environment (lungs), hemoglobin has a reduced affinity for CO2
what is the bohr effect?
acidic environments (tissues) reduces the affinity of hemoglobin for oxygen
what are the control mechanisms of respiration?
local controls (bronchioles and alveolar blood flow)
CNS (respiratory control centers)
peripheral chemoreceptors
CNS chemoreceptors
how do local control mechanisms work to control respiration?
if ventilation decreases in a group of alveoli, Pco2 increases while Po2 decreases. blood flowing past these alveoli will not be oxygenated.
decreased tissue Po2 around underventilated alveoli constricts their arterioles, diverting blood to better ventilated alveoli
how do the bronchioles react to the following conditions?
Pco2 increase
Pco2 decrease
Po2 increase
Po2 decrease
dialate
constrct
constrict
dialate
how do the pulmonary arterioles react to the following conditions?
Pco2 increase
Pco2 decrease
Po2 increase
Po2 decrease
constrct
dialate
dialate
constrict
how do the systemic arterioles react to the following conditions?
Pco2 increase
Pco2 decrease
Po2 increase
Po2 decrease
dialate
constrict
constrict
dialate
where are the respiratory control centers located in the brain?
the pons and medulla
what control centers are located in the pons?
pneumotaxic center
apneustic center
what does the pneumotaxic respiratory center do?
sends inhibitory impulses to the inspiratory center, terminating inspiration, and thereby regulating inspiratory volume and respiratory rate.
feeds into DRG to inhibit respiratory neurons
what does the apneustic respiratory center do?
controls the intensity of breathing, giving positive impulses to the neurons involved with inhalation. gives a smooth breath
The apneustic center is inhibited by pulmonary stretch receptors and also by the pneumotaxic center.
It also discharges an inhibitory impulse to the pneumotaxic center.
what does damage to the apneustic center cause?
gasping breaths
what is the pre-botzinger complex thought to do?
thought to initiate the breathing instinct.
what control centers are located in the medulla?
dorsal respiratory group
ventral respiratory group
what does the dorsal respiratory group do?
primarily timing of the respiratory cycle. The DRG is composed of mostly inspiratory, primary neurons and quiet in exhalati9on.
responsible for normal tidal volume
These neurons initiate activity in the phrenic nerves, which innervate the diaphragm.
what does the ventral respiratory group do?
contain the essential circuitry generating the basic respiratory rhythm as well as the varying augmenting and decrementing patterns of respiratory motor output evident on cranial and spinal nerves
responsible for inhalation and exhalati9on
quiet in passive breaths
accessory for max breathing
what does the phrenic nerve do?
controls your diaphragm
usually from signals from the DRG
what is the herring-breurer reflex?
uses bronchiole stretch receptors in smooth muscle. blocks the over inflation of the lungs by inhibiting DRG excitation of the phrenic nerve
what is the voluntary control of respiration?
irritation of the nasal passages (coughing/sneezing), pharynx, larynx or trachea causing cough
fright causes rapid inhalation and vocalization
what is the carotid sinus and where is it located?
a bulb in the carotid artery near the top
controls BP
what are carotid bodies and where are they located?
a sensory organ of the PNS
located above the carotid sinus
what are aortic bodies and where are they located?
collections of chemoreceptors
located on the aortic notch
describe how a carotid body can increase oxygen in the blood;
1: low oxygen is sensed
2: closure of K channels occurs
3: the cell depolarizes
4: voltage gated Ca channels open
5: Ca enters the cell
6: exocytosis of dopamine containing vesicles occurs
7: an action potential is initiated by binding of dopamine to dopamine receptors
8: the action potential signals medullary centers to increase ventilation
