exam 2 Flashcards
Boyles law
in a closed container, pressure and volume are inversely proportional
describe volume and pressure changes during inspiration and how does the pressure affect the size of the lungs
inspiration: volume in the chest increases which results in a decrease in pressure, which creates a partial vacuum, pulling air into the lungs
describe volume and pressure changes during expiration and how does the pressure affect the size of the lungs
volume in the chest decreases, which results in an increase in pressure, pushing the air out of the lungs
what kind of pressure is found in the pleural cavity
since the chest wall and lungs are moving away from each other the volume in that space increases which causes a negative pressure in that space, negative pressure (vacuum) will cause the lungs to expand
what do the muscles of normal breathing contract and relax
the respiratory muscles contract during inspiration and relax during expiration
describes the effect of the DRG on the respiratory muscles
DRG causes inspiration so it would stimulate the respiratory muscles to contract
describes the effect of the VRG on the muscles
VRG causes forced expiration so it would prevent the contraction of the respiratory muscles and stimulate contraction of expiratory muscles
describes the effect of the apneustic center on the muscles
apneustic center increases inspiration so it would stimulate the contraction of respiratory muscles for a longer time
describes the effect of the pneumotactic center on the muscles
pneumotactic center limits inspiration so it would decrease the contraction of the respiratory muscles
what is the normal V/Q ratio
the normal ratio is 1
describe how the V/Q ratio differs for shunt vs during physiological dead space
- during a shunt, the V/Q ratio decreases
- during dead space, the V/Q ratio increases
describe the effect of the sympathetic nervous system not he bronchioles
sympathetic nervous system causes dilation of the bronchioles, increase ventilation and V/Q ratio
describe the effect of the parasympathetic on the bronchioles
parasympathetic nervous system causes constriction of the bronchioles, decreases ventilation and V/Q ratio
describe the effect of the sympathetic and parasympathetic nervous system activation on the likelihood of developing a shunt or dead space
- sympathetic nervous system = dead space
- parasympathetic nervous system = shunt
since the left lung is smaller than the right lung the volume of the space surrounding the left lung is larger than the volume of space surrounding the right lung. explain the difference in the pressure in the space surrounding the left lung vs the space surrounding the right lung and which would then be easier to inflate
- left lung is greater than the space surrounding the right lung the
- pressure in the space surrounding left lung is lower than the pressure surrounding the right lung
- left is easier to inflate
define restrictive lung disorder
problems with inspiration - breathing in
define obstructive lung disorder
problems with expiration - breathing out
give a function for DRG
pacemaker cell in the medulla that activates the normal respiratory muscles, causing inspiration
give a function for apneustic center
pacemaker cell in pons increases the activity of the DRG prolonging inspiration
give a function for pneumotactic center
pacemaker cell in pons decreases activity of the DRG limiting inspiration
give a function for VRG
pacemaker cell in medulla that only become active when air must be forced out of the lungs
describe how the activity of each of these respiratory pacemakers would different for a restrictive disorder vs obstructive disorder
- restrictive disorder: need to have increased DRG activity, caused by increased activity of the apneustic center and decreased activity of pneumotactic center
- obstructive disorder: would need to have decreased DRG activity which would be caused by decreased activity of the apneustic center and increased activity of the pneumotactic center; it would also require the VRG