respiratory iii

gases are exchanged by diffusion between

blood, lungs and tissue

the amount of air that moves in and out of the lungs depends on conditions breathing (inhalation/exhalation), we describe as

respiratory volumes

in spirometry test, if forced expiratory volume is less than 80% of forced vital capacity, then air trapping lung disease likely __ may be the issue

copd

in spirometry test. if forced vital capacity is less than normal but forced expiratory volume is 80% or more of their forced vital capacity, patient may have restrictive air disease like

asthma or pulmonary fibrosis

you can gain information about a person respiratory health by measuring specific combinations of respiratory volumes which is

respiratory capcities

What respiratory volume is this: amount of air inhaled or exhaled with each breath under normal conditions (quiet breathing)

Tidal volume

What respiratory volume is this: amount of air that can be forcefully inhaled beyond tidal volume inspiration (how much more can be inhaled)

Inspiratory reserve volume

both internal and external respiration rely on

partial pressure gradients

external respiration is

gases exchanged between lungs and blood

internal respiration is

gases exchanged between blood and tissues

what three layers makeup the respiratory membrane within the alveoli

alveolar epithelium, fused basement membranes of both of these epithelium and capillary endothelium

where does gas exchange occur

type i alveolar cell

if PO2 is 104mmHg in alveolus and 40mmHg in the capillary, where will oxygen go__ while Co2 will go in opposite direction

out of alveolus and into capillary

what is the minimum amount of time needed for pulmonary capillaries to become oxygenated and reach equilibrium at 104mmHg

0.25s

0.75s is given in case

pulmonary capillaries require more time to become oxygenated (buffer)

what are the two factors that affect gas exchange

partial pressure gradients and thickness and surface area of respiratory membrane

how can surface area of respiratory membrane be reduced (which ultimately decreases gas exchange)

due to emphysema that destroys the alveolar walls

will someone with emphysema require more or less time to become oxygenated

more than 0.25s

how does left sided CHF also decrease SA and in turn slow gas exchange

fluid in alveoli

how can we see increase in membrane thickness

inflammation from asthma, infections, pneumonia or tb

increase in membrane thickness = decreases diameter of bronchioles = __ = slower gas exchange

increases resistance

solutions to poor diffusion of gases may include increasing o2 diffusion gradient across membrane, what are ways in which that is achieved

constant low flow O2

with nasal cannula (constant o2 supplement) we see an increase in o2 supply in the alveoli (normal: 104mmHg vs. 250mmHg) what does this mean for gas exchange

greater o2 gradient = faster diffusion

what type of therapy is this: placing a patient in a sealed chamber and adding pure o2 to raise PO2s of 2000-3000mmHg

hyperbaric therapy

hyperbaric therapy is useful in which instances

carbon monoxide poisoning and treating hypoxic tissue (gangrene or diabetic ulcer)

why is hyperbaric therapy a temporary solution (both adults and infants)

free radicals (cancer), CNS disturbances (coma), optic nerve damage (blindness)

how does hyperbaric therapy help for diabetic foot ulcers

increase in o2 promotes epithelial tissue healing because of increasing phagocytosis

what are the two ways in which o2 is carried

bound to hemoglobin at heme group and dissolved in plasma

for each ¼ or 25% saturation, there is __ binding Hb

1 O2

what respiratory volume is this: amount of air that can be forcefully exhaled beyond tidal volume expiration

expiratory reserve volume

what is Bohr’s effect

shifts oxygen hemoglobin dissociation curve to right, making o2 delivery faster

at what saturation and PO2 (arterial pressure) does tissue hypoxia start occurring, due to inadequate o2 delivery

75%, 40mmHg

at what saturation and PO2 (arterial pressure) is hypoxic drive to increase RR triggered

90%; 60mmHg

when is saturation of 98% and PO2 of 75-80mmHg considered ok

high altitudes

what PO2 and saturation indicates freshly oxygenated blood

100mmHg; 98%

what type of hypoxia is caused by these factors: not enough Hb, too few RBCs or improperly made RBCs that leads to death

anemic hypoxia

what type of hypoxia can be caused by systemic blockage by MI or localized blockage (thrombus, embolus) that prevents o2 from getting through

ischemic hypoxia

what type of hypoxia is caused by arterial PO2 being low, probable diffusion problem in lungs

hypoxemic hypoxia

during exercise o2 saturation of blood leaving tissues in veins can

decrease to 25% (15mmHg)

how do we correct the decrease PO2 by exercise

Bohrs effect that increases CO2, temperature and decreases pH so cells can get more O2

what is the carbonic acid formula used for CO2 transport/exchange (change form of co2 to hco3-)

CO2 + H20 (using CA) H2CO3 - HCO3- + H+

what is CA in the carbonic acid formula; and what does it do

carbonic anhydrase; converts Co2 into carbonic acid (located in RBC)

what is the carbonic acid in the formula

h2co3

anytime CO2 increases, we see an increase in __ and decrease in __

H+; pH

how much Co2 is transported by plasma, bound to globin chain on Hb and as HCO3-

10%, 20%, 70%

what is PCO2 in tissues vs capillary

less than 45mmHg; 40mmHg

do we see chloride shift (to maintain membrane potential when removing a negative) in RBC of systemic capillary or pulmonary

systemic

from tissue cells to RBC in systemic capillary we see arrows to right or left

right

in RBC located in pulmonary, Cl- is kicked out and switched back with HCO3-, during transport to alveolar sacs are the arrows to right or left

left

what is PCO2 in capillary vs alveolar sacs

45mmHg vs 40mmHg

respiratory centers in brain stem control breathing with input from

chemoreceptors and higher brain centers

where are the peripheral chemoreceptors (the ones that control breathing) located

aorta and carotid sinuses

what do the peripheral chemoreceptors do

check to see if PO2 is 100mmHg and PCO2 is 40mmHg and H+ is 7.4

normal respiration rates (12-16bpm) are set by the medulla oblongata that sends messages down phrenic and intercostal nerves at cervical region, what happens if neck is broken

stop breathing

is o2 or co2 a major regulator of breathing

co2

fill this in: if PCO2 increases, PO2 __ and H+ __ (stimulus to increase respiration rate and depth)

decreases; increases

fill this in: if PCO2 decreases, PO2 __ and H+ __ (stimulus to decrease respiration rate and depth)

increases; decreases

as any respiratory function (ventilation, external respiration, transport, internal respiration) decreases what increases

co2

when respiratory function decreases and co2 increases, what may result from high CO2

hypercapnia

5mmHg increase in PCO2 levels will cause 100% increase in __ while PO2 would need to drop less than __mmHg for urgency to breathe (hypoxic drive)

breathing rate; 60

what is apnea

absence of breathing

with apnea we see decrease in O2 levels which increases __ and forces heart to work harder (will eventually see heart failure)

EPO = RBC and thicker blood

what is hyperventilation

breathing more out than in

hyperventilation can lead to __ because of low CO2 levels (associated with dizziness and fainting)

hypocapnia

what is hyperpnea

increase in respirations (both in and out) during exercise or fever

what type of respiratory disease is long term irreversible destructive lung disease with increasing inability to force air out of the lungs; disease of trapped “old'“ air

chronic obstructive pulmonary disease

what leads to COPD

tobacco smoke and air pollution

what are the two main causes/routes for copd

chronic bronchial irritation and inflammation that causes chronic bronchitis and breakdown of elastin in connective tissue of lungs that causes emphysema

both chronic bronchitis and emphysema for copd result in

airway obstruction or air trapping (hypercapnia, acidosis and hypoxemia), dyspnea, hypoventilation, and frequent infections

how is asthma different from copd

effects are reversible; can range from acute to symptom free

what type of respiratory disease is this: temporary bronchospasm obstructs already inflamed respiratory bronchioles

asthma

because airways are hypersensitive due to always being inflamed (with asthma), this makes

bronchospasms worse and causes exudate in airway

pulmonary tb is caused by mycobacterium tuberculosis and is spread by coughing, sneezing (any respiratory droplets), enters via inhaled air and can spread via lymphatics what is the order from primary to active

primary - latent (immune system creates tubercles of bacteria)- active

lung cancer is primarily from smoking meaning it is or is not preventable

preventable

what are the three types of lung cancer

small cell carcinoma, adenocarcinoma, squamous cell carcinoma

what respiratory volume is this: amount of air remaining in lungs after a forced expiration

residual volume

what respiratory capacity is this: maximum amount of air that can be inspired after a normal tidal volume expiration

inspiratory capacity

what respiratory capacity is this: maximum amount of air that can expired after a maximum inspiratory effect (everything you can move)

vital capacity

what respiratory capacity is this: maximum amount of air contained in lungs after a maximum inspiratory effect (everything including residual volume)

total lung capacity

what is formula to calculate inspiratory capacity (IC)

tidal volume + inspiratory reserve volume

what is formula to calculate vital capacity (VC)

tidal volume + inspiratory reserve volume + expiratory reserve volume

how to calculate total lung capacity (TLC)

tidal volume + inspiratory reserve volume + expiratory reserve volume + residual volume