Respiratory Physiology Part 1 Flashcards
lecture 2
function of respiratory
exchange of oxygen and carbon dioxide b/w the environment and the cells of the body
conducting zone
brings air into and out of the lungs
respiratory zone
lined with alveoli
gas exchange occurs
structures of conducting zone
nose, nasopharynx, larynx, trachea, bronchi, and bronchioles
effects of conducting zone on air
it warms, humidifies and filters air before it reaches gas exchange
Mucus and cilia in the conducting zone
remove inhaled particles
movement of cilia
upward rhythmic beating
what can paralyze cilia / mucus mechanism
inhalation of smoke
Sympathetic effects on conducting zone
Beta 2 = dilation of airway
Parasympathetic effects on conducting zone
muscarinic receptors = contraction
examples of Beta-2
epinephrine and albuterol
asthma treatment
structures that participate in respiratory zone
bronchioles
alveolar ducts
alveolar sacs
alveoli
bronchioles
cilia and smooth muscle
alveolar ducts
lined with alveoli
no cilia and very little smooth muscle
gas exchange occurs in
alveoli
each lung has 300 million alveoli
why does gas exchange happen rapidly and efficiently
alveolar walls are thin and have large surface area
surfactant
reduce surface tension of alveoli
what would happen if we didn’t have surfactant
the lungs would collapse
macrophages in respiratory zone
another line of defense
b/c there is no cilia , macrophages keep alveoli free from dust & debri
CO of lungs
receive 100% of CO from pulmonary artery (heart)
Gravitational effects on pulmonary blood flow
Standing –> blood flow is lowest at apex (top) and highest at base (bottom)
Supine–> gravitational effects disappear
lung volumes
tidal volume
inspiratory reserve volume (IRV)
Expiratory reserve volume (ERV)
Residual volume
tidal volume
volume of air that fills the alveoli + the volume of air that fills the airway
500 mL
Inspiratory reserve volume
IRV
additional volume that can be inspired above tidal volume
3000 mL
Expiratory reserve volume (ERV)
the additional volume that can be expired below tidal volume
1200 mL
Residual volume
volume of gas remaining in the lungs after maximal forced expiration
1200 mL
Lung capacities
Inspiratory capacity (IC)
Functional Residual Capacity (FRC)
Vital Capacity (VC)
Total Lung Capacity (TLC)
inspiratory capacity (IC)
Tidal volume + Inspiratory reserve volume (IRV)
3500 mL
Functional residual capacity (FRC)
expiratory reserve volume (ERV) + residual volume (RV)
2400 mL
remaining volume in the lungs after TV is expired
FRC can also be thought of as
equilibrium of the lungs
Vital Capacity (VC)
inspiratory capacity (IC) + expiratory reserve volume (ERV)
4700 mL
volume expired after maximal inspiration
vital capacity can increase with
body size
male gender
physical conditioning
total lung compacity (TLC)
all lung volume
vital capacity + residual volume
5900 mL
Dead Space
volume of the airways and lungs that does not participate in gas exchange
Anatomic Space
volume of conducting airways
-when tidal volume is inspired, the entire volume does not reach the alveoli for gas exchange
At the end of expiration conducting airways are filled with ___
alveolar air
-filled with air that has already been in the alveoli and gas exchange
After expiring air & the inspiration of the next tidal volume what happens to alveolar air ?
alveolar air is first to enter the alveoli
physiologic dead space
total volume of the lungs that does not participate in gas exchange
dead space of conducting airways + functional dead space of alveoli
ventilation rate
volume of air moved into and out of the air per unit of time
minute ventilation
total rate of air movement into & out of the lung
Tidal Volume x (breaths/min)
alveolar ventilation corrects for
physiologic dead space
alveolar ventilation
describes inverse relationship between alveolar ventilation and alveolar PCO2
(the lower the alveolar ventilation , the less CO2 is pulled out of blood & the higher the PaCO2)
Alveolar ventilation equation
(TV- Physiologic dead space) x breaths/min
Forced Vital Capacity
total volume of air that can be forcibly expired after max inspiration
forced vital capacity in healthy lungs
can get all air out in 3 seconds
