Lab 4 - Respiratory Flashcards
what is the purpose of cartilage rings
to maintain open airways, when there is a drastic pressure change
what does the C-shape of cartilage rings allow
food to move down the esophagus
what do C shaped rings change to when going down the tract
cartilage plates
what happens to the cartilage plates as you move down the tract
they disappear
what is different about bronchioles
no cartilage, smooth muscle instead
what is the site of gas exchange
alveoli
what do alveoli carry
residual air
what keeps alveoli and bronchioles open
the residual air - lung recoil
what is ventilation
bulk flow of air between atmosphere and the respiratory zone (alveoli)
what does an increased diameter result in
decreased resistance –> increased flow
what does a reduced diameter result in
increased resistance –> reduced flow
how does the body create low and high pressure in the thoracic cavity
Boyle’s gas law: P1V1 = P2 V2
inspiration
airflow into lungs due to low pressure in lungs
what is expiration
air flow out of lungs due to high pressure in lungs
what does inspiration require
expanding of thoracic cavity
what type of mechanism is inspiration
an active mechanism by contracting the inspiratory muscles
3 steps of inspiration
- volume increases
- pressure in lungs lowers below atmospheric pressure
- air flows into lungs until an equilibrium is reached
what does expiration require
shrinking of the thoracic cavity
what type of mechanism is expiration
passive - by relaxing the inspiratory muscles, allowing lungs to recoil due to elasticity
3 steps of expiration
- volume decreases
- compression of gas within the lungs to a pressure higher than the atmospheric pressure
- air flows out of lungs until an equilibrium is reached
when does resistance increase
narrowing of trachea –> resistance increases –> reduced airflow
(increased pressure)
what is vital capacity
max capacity of air that can be moved in and out of lungs
residual volume
residual volume of air that is always in the lungs
