Ventilation Flashcards
How do mammals breath?
By ventilating their lungs.
What is Ventilation?
The movement of air into (inspiration) and out of (expiration) the lungs
What is ventilation controlled by?
The movements of the diaphragm, rib cage and intercostal muscles.
What are the 2 types of intercostal muscles?
Internal and External
What are the Internal Intercostal muscles?
-Underneath
-Involved in forces expiration
What are the External Intercostal muscles?
-On Top
-Involved in normal ventilation
What is the first step during inspiration?
The external intercostal muscles and diaphragm conrtact
What is the second step during inspiration?
The ribcage moves up and out so the volume of the thorax increases
What is the third step during inspiration?
The air pressure in the lungs reduces to less than atmospheric pressure.
What is the fourth step during inspiration?
Air flows into the lungs.
What is the first step during expiration?
The external intercostal muscles and diaphragm relax
What is the second step during expiration?
The ribcage moves down and in so the volume of the thorax decreases
What is the third step during expiration?
Air pressure in the lungs increases to above than atmospheric pressure
What is the fourth step during expiration?
Air flows out of the lungs
What happens during forces expiration?
External intercostal and diaphragm muscles relax the internal intercostal muscles and abs contract to pull the ribcage down/diaphragm up with more force.
-Requires energy
What is Tidal Volume?
The volume of air inhaled/exhaled per breath at rest.
What is Total Lung Capacity?
The maximum volume of air that lungs can hold.
What is Vital Capacity?
The maximum volume of air that can be expelled after forced inspiration.
What factors effect Vital Capacity?
-Height
-Age
-Gender
-Regular Exercise
What is Residual Volume?
Volume of air left in the lungs after forces expiration (usually 1L)
What is Breathing Rate?
The number of breaths taken per unit of time (usually 1 minute)
What is Oxygen Uptake?
The rate at which a person uses up oxygen.
What are Spirometers used for?
To analyse lung function by measuring ventilation.
What are the 4 precautions which should be taken when using a Spirometer?
-Subject should be free of asthma
-No air leaks in apparatus
-Sterilised mouthpiece
-Soda lime should be fresh and functioning.
