Respiration - Weeks 1 to 4 Flashcards
What is the function of the respiratory system?
To ensure that tissues are supplied with adequate O2
To remove CO2 from the lungs produced in metabolism
It does this via gas exchange and blood transport
What is tidal volume?
The volume which is taken in in one breath at rest (quiet respiration)
Define ventilation
The mechanical system which allow to lunds to expand and supply air to the lungs
Define the inspiratory reserve volume
The extra air breathed in, when we breathe deeper at rest
The opposite of the expiratory reserve volume
What creates pressure exerted by gases?
Gas molecules move about and collide, the more frequent or harder the collision, the more pressure a gas can exert
What is partial pressure?
The pressure exerted by a single gas in a mixture. Usually is equal to its percentage in the mixture.
Gases diffuse down partial pressure gradients
Boyle’s Law?
States that pressure is inversely proportional to volume
If constant temperature and constant amount of gas
As more collisions if higher volume in same space
Is a measure for O2 availability
How does Boyle’s Law apply to respiration?
As in inspiration, we are making the lung volume bigger which decreases the pressure in the lungs, so air flows into the lungs (as lower pressure to outside air)
Also, at altitude, air is at a lower pressure so the molecules are further away, so the amount of O2 received in one breath is lower at higher altitude.
Charles’ Law?
States that gases have more energy at higher temperatures, which increases pressure, due to more collisions
Pressure is proportional to Temperature
How do gases interact with fluid?
Dynamic- water can evaporate and gases can dissolve
Water exerts vapour pressure (saturated vapour pressure) when at equilibrium and at a constant temperature
Why is saturated vapour pressure important in respiration?
As gases mix with water in the airways, so SVP contributes to the pressure in the lungs
What is tension?
Equal to the partial pressure, exerted by gases when dissolved in fluid
NOT equal to the amount dissolved, cause gas can react with components
How do you work out how much gas is in fluid?
Amount of gas dissolved in a fluid= tension x solubility
What are the branches after the terminal bronchioles?
The respiratory bronchioles
The alveolar ducts
Alveolar sacs (surrounded by pulmonary capillary network)
Give some features of the pulmonary circulation
Low resistance
Low pressure
Receives the whole cardiac output
Matched by ventilation via hypoxic vasoconstriction
