Ventilation and the spirometer Flashcards
Describe quiet Inhalation
Diaphragm contracts and moves down
External intercostal muscles contract and ribcage raises
pressure is lower than atmospheric pressure in lungs
volume of chest cavity increases
air moves out
describe expiration
Diaphragm relaxed and moves down
External and internal intercostal muscles relax
ribcage falls
Volume in chest cavity decreases
pressure is higher than atmospheric pressure
air leaves
describe forced expiration
intercostal muscles contract
abdominal muscles contract
pressure has increased
volume has decreased
air leaves long quickly
what are the precautions of the spirometer
Make sure mouth piece is sterilised
subject must be healthy
water tank cant be overfilled
fresh soda lime
no air leaks in apparatus
what is a spirometer
a device which measures movement of air in and out of the lungs during breathing.
why must a subject wear a nose clip doing the spirometer test
stop inspiration or expiration through nasal cavity
what is the function of the soda lime in the spirometer
Absorbs carbon dioxide, allowing us to only measure oxygen consumption
describe the process of using a spirometer
Subject uses face mask to breathe in
air leaves chamber
lid then moves down as volume decrease.
the pen attached to the lid will move down and draw lower lines on the data logger.
The spirometer consists of a tank of water and a chamber on top, What is in this chamber
Medical- grade oxygen
how do you calculate the gradient of a line
Change in Y/ CHange in X
Spirometers can allow us to calculate lung volumes. How do you calculate the total capacity
Vital capacity + residual volume
what is vital capacity
max volume of air moved by lungs in a single breath
how do we measure vital capacity
take a deep breath and expell all air in lungs
What is residual volume
volume of air which remains in lungs after expiring all air possible
what is the tidal volume
volume of air moved in and out of lungs during normal breathing
