Respiratory phys. Lung Vol and capacities 1 of 2 Flashcards
what are the four main funcitonso f the respiratory sytstem?
- exchange gases between the atmosphere and the blood
- homeostatic regulation of blood pH
- Protection from inhaled pathogens and irritating substances
- vocalization
differentiate between external and celluar respiration
- external
- movement of gases between the enviornment and the bodys cells
- cellular respiration
- intracellular reaction of O2 with organic molecules to prduce CO2, water andATP
what are the four phases of external respiration?
- exchange of air between the atmosphere and the lungs
-
ventilation/breathing
- inspire/exspire
-
ventilation/breathing
- exchange of O2 and CO2 between the lungs and the blood
- transport of O2 and CO2 by the blood
- exchange of gases between blood and the cells
what organizes the flow of air into and out of the lungs?
Conducting zone
what division is lined with alveoli and facilitates gas exchange?
respiratory zone
what temp and humidity does the conducting zone act on the inspired air?
warm: 37C
humidify: 100%
trachea and bronchi are lined by two major cell types
- function
- secretions of each
Epithelial cells/ goblet cells
- filtration and ciliated respritory epithelium
- goblet- secret mucus
- epithithelial- secrete dilute saline
- cilia move the mucus layer toward the phrynx, removing trapped pathogens and particulate matter
what does smoking do?
paralyzed cilia, increasing mucus-> smokers cough
explain the difference between cilliary dyskenesia and cystic fibrosis.
how can you test some one for cystic fibrosis?
- ciliary dyskenesia
- genetic disorder where person has malformed cillia and they do not funciton properly, males are sterile (sperm)
- Cystic fibrosis
- mustated CFTR: cyteic fibrosis transmembran conductance regulator
- water does not move into airways with osmosis
- lack of slaline layer make thick sticky mucuc
- mucus remains in the airway
- recurring lung infection
- test
- sweat test
- normal sweat ducts use the CFTR to reabsorb water as the isotonic solution travels down the duct. this generates a hypotonic
- Mutation in the CFTR leads to hypotonic - isotonic sweat.
- sweat test
what is the location of dead space?
150mL in the conducting zone - do not participate in gas exchange
What are the important layers on the respiratory epithelium
watery layer in contact with the cilia, mucos layer superficial to the watery layer.
This watery layer is important b/c the cilia cannot beat in the mucus layer.
patietns with cystic fibrosis have no watery layer and cannot remove the mucus, b/c the cilia cannot beat
______ leads to the Activation of what receptor leads to muscle relaxation and dilatino of the airway
sympathetic adrenergic neurons activate B2 receptors
- B2 adrenergic agonists
- epinephrine
- albuterol
_____ activates this receptor leading to contraction and constriction
parasympathetic cholinergic neurons activate muscarinic receptor
- muscle contraction and constriction of airways
what is included in the respiratory zone?
- respiratory bronchioles
- alveolar ducts
- alveolar sacs
- alveoli
how many alveoli are present in each lung?
300 million
Blood flow with respect to the lungs is
- highest in the
- lowerst in the
- hiest at the base (bottom)
- lowest at the apex(top)
laying down decreases this affect
how is blood flow regulated with respect to resistance?
pulmonary blood flow is regulated by alterin the resistance of the pulmonary arterioles
- O2 is the main factor
descrive the respriration
- O2 molecules react to produe CO2, water and ATP
cellular respiration: intracellular reaction of O2 with organic molecules to produce CO2, water and ATP
describe the type of respiration
- movement of gases from eviornment and the bodys cells
external respiration: movement of gases between the environment and the body’s cells
what two items make up a respiratory cycle?
inspiration + expiration
define the following terms
- Vt
- IRV
- ERV
- RV
- tidal volume
- the volume of air fluctuating the most of the time. during normal, quiet breathing
- 500ml
- inspiritory reserve volume
- the maximum amount of air that can be added to normal tidal volume
- 3000ml
- expiratory reserve volume
- amount of air that can be expired in addition to norma ltidal expiration, just following normal breathing
- 1200ml
- residual volume
- volume of air remaining in the lungs after a max forced expiration
- NOT MEASURABLE ON SPIROMETER
Define the inspiritory capacity
inspiratory capacity = Vt + IRV
define Vital Capacity
Vital capacity = Vt + IRV +ERV
- ~4700ml
- the maximum amount of air that can be moved through the lungs
- increases with body size, male gender and physical conditioning
define
total lung capacity
total lung capacity = Vt + IRV + ERV +RV
- TLC is the toal volume of air that the lungs can hold
- since RV cannot be measured by spirometry, TLC cannot be measured by spirometry
define the functional residual capacity
Functional residual capacity = ERV +RV
- this is the volume remaining in the lungs after a normal tidal volume is expired; it can be though of as the equilibrium volume of the lungs
- Since RV cannot be measured via spirometry, FRC cannot be measured by spirometry
Of the volumes used to describe the lungs which can and cannot be measured by spirometry.
- can be measured
- inspiratory capacity = Vt + IRV
- Vital capacity = VT +IRV + ERV
-
CANNOT BE MEASURED- b/c RV cannot be measured
- total lung capacity = Vt +IRV +ERV +RV
- Functional residual capacity = ERV + RV
volume of the airways and lungs that does not participate in gas exchange?
dead space = anatomic dead space is the volume of the conducting airways
- 150ml
- accounting for the space in the nose/mouth, trachea, bronchi, and bronchioles
for a typeical Vt of 500ml, how much actually meet the alveoli?
500ml
dead space = 150ml
500-150=350
350ml
this freshly inspired air is mixed with alveolar air from the precious breath
pulmonary embolism blocks the alveoli and is equivilent to generating more
dead space
normally ventilation and perfusion are well matched, but certain pathologies cause an increase in physiologic dead space.
how can you calculate the physiologic dead space?
- how much CO2 is estimated to be inspired
- location of CO2 from expired air
- Dead space contribution to CO2
- formula
- What is needed for the above formula?
- almost no CO2 in inspired air
- CO2 in expired air comes from exhange in functioning alveoli
- presence of dead space dilutes the CO2
- Dead space neither exchanges nor contributes CO2
- Volume of the physiologic dead space = Vt x ((PaCO2-PeCO2)/PaCO2)
- fraction represents the dilution of alveolar CO2 be dead space
- since alveolar air can’t be sampled directly, the CO2 in systemic arterial blood is used to estimate the CO2 in air
minute volume =
*
Total pulmonary ventilation = minute volume
- determines the efficiency of breathing
- volume of air moved into and out of the lungs/min
- TPV = ventilation rate x Vt
- Normal adult
- 12-20breaths/min
- ave Vt = 500 ml
- ~TPV = 12 breathes/min x 500mL/breaths
- = 6000mL/min->6L/min
- Normal adult
- But this is not the amount of fresh air reaching the alveoli b/c anatomic dead air space ~150mL, so subtract 150mL per breath?
compare TPV to AV
Total pulmonary ventilation- does not take into account of dead space
- 6000mL
Alveolar Ventilation - makes adjustment for the anatomic dead space
- 4200mL
- Va =(Vt-Vd) x breathes per minute
check values
Define FVC and FEV
- FVC= forced vital capacity
- this is the total volume of air that can be forcefully expired after a maximal inspration
- FEV = Forced expiratory volume
- is the volume expired in the first second
describe the following charts. Determine the ratios
- normal
- FEV/FVC
- 4/5=0.8
- 80%
- FEV/FVC
- obstructive disease
- asthma
- FEV/FVC
- 2/3 = 0.67
- below80%
- restrictive disease
- fibrosis
- FEV/FVC
- 4/4=0
- above 80%
interpret the following charts.
Normal/resting state
end of tidal volume
what is the volume of dead space?
150mL
what is the resting location of the lung?
FRC= where the lung collapse and chest wall are equal in pressure.
