Respiratory system:
• Nose
• Pharynx - throat region
• Larynx - voice box
• Trachea - wind pipe. Has cartilage rings so it doesn’t collapse as air enters.
• Bronchi (right and left main bronchus) — right is slightly more vertical since
if food is aspirated, food will go down right (preferred). Thus pneumonia in
right lung is more common since food will be aspirated there more
commonly.
• Bronchioles — end of conducting portion (air conduction(
• Alveoli — where gas exchange occurs (respiratory portion). Not all air that is
inhaled is available for gas exchange — just air that enters alveoli!
Respiratory cycle — one complete cycle of inspiration (inhalation) +
expiration
Respiration has 3 meanings — 1) process of breathing (inhale and exhale), 2)
internal respiration (gas exchange), 3) cellular metabolism (ATP generation)
• Inhalation — air flow into the lungs. Active process (uses ATP) since makes
muscle contracts, increase thoracic cavity.
• Anatomical dead space — Not all air that is inhaled is available for gas
exchange — just air that enters alveoli! So the air that remains in the
conducting portion (anatomical dead space) is “dead air. “So if inhale 500
mL of air, only 350 mL will enter alveoli, 150mL is dead.
• Alveolar Ventilation Rate (AVR) = air entering alveoli x RR
(respiratory rate = 12 breaths per minute). Example 350 mL x 12 = 4200
mL per minute. Importance — gives us most relevant measurement of
how body takes oxygen from air and supplies tissues with that oxygen.
Tells us body’s ability to remove Co2 as well.
• Exhalation — passive process (no ATP). Lungs recoil, diaphragm recoils,
thoracic cavity decreases, air flow out. (Forced exhalation is active though,
I.e. when exercising)
• Residual volume — not all air in alveoli is expelled (usually 1300 mL
of air). During inhalation, dead air (remaining air from previous cycle) is
flushed out and refreshed/replaced.
, Pulmonary values
Importance (why) — helps assess pulmonary function, assess severity of
pulmonary disease, can monitor improvement and deterioration in patient
• Spirometer — device recaptures expired air. Tells us rate and depth of
breathing, speed of expiration, rate of oxygen consumption.
• Spirometry — measurement of pulmonary function. Aids diagnosing lung
disorders that are restrictive vs. obstructive disorders.
Restrictive disorder — any disorder where lungs are limited in amount of air
that can be inflated (inability to inflate and bring air in)
Pulmonary Fibrosis — scarring of lungs. Tuberculosis, black lung.
Can’t inflate and bring in as much air as usual.
Obstructive disorder — interfere air flow by restricting or blocking airway so
limits amount of air that can inhaled or exhaled.
Example — asthma, chronic bronchitis
Emphysema — both restrictive and obstructive.
Pulmonary measurements
Proportional to body size, so values generally higher in males than females.
Volumes
• Tidal Volume — amount of air inhaled or exhaled in one breath during
quiet breathing. About 500 mL.
• Inspiratory Reserve Volume (IRV) = VC - (TV + ERV). 3000 mL
in males.
• Nose
• Pharynx - throat region
• Larynx - voice box
• Trachea - wind pipe. Has cartilage rings so it doesn’t collapse as air enters.
• Bronchi (right and left main bronchus) — right is slightly more vertical since
if food is aspirated, food will go down right (preferred). Thus pneumonia in
right lung is more common since food will be aspirated there more
commonly.
• Bronchioles — end of conducting portion (air conduction(
• Alveoli — where gas exchange occurs (respiratory portion). Not all air that is
inhaled is available for gas exchange — just air that enters alveoli!
Respiratory cycle — one complete cycle of inspiration (inhalation) +
expiration
Respiration has 3 meanings — 1) process of breathing (inhale and exhale), 2)
internal respiration (gas exchange), 3) cellular metabolism (ATP generation)
• Inhalation — air flow into the lungs. Active process (uses ATP) since makes
muscle contracts, increase thoracic cavity.
• Anatomical dead space — Not all air that is inhaled is available for gas
exchange — just air that enters alveoli! So the air that remains in the
conducting portion (anatomical dead space) is “dead air. “So if inhale 500
mL of air, only 350 mL will enter alveoli, 150mL is dead.
• Alveolar Ventilation Rate (AVR) = air entering alveoli x RR
(respiratory rate = 12 breaths per minute). Example 350 mL x 12 = 4200
mL per minute. Importance — gives us most relevant measurement of
how body takes oxygen from air and supplies tissues with that oxygen.
Tells us body’s ability to remove Co2 as well.
• Exhalation — passive process (no ATP). Lungs recoil, diaphragm recoils,
thoracic cavity decreases, air flow out. (Forced exhalation is active though,
I.e. when exercising)
• Residual volume — not all air in alveoli is expelled (usually 1300 mL
of air). During inhalation, dead air (remaining air from previous cycle) is
flushed out and refreshed/replaced.
, Pulmonary values
Importance (why) — helps assess pulmonary function, assess severity of
pulmonary disease, can monitor improvement and deterioration in patient
• Spirometer — device recaptures expired air. Tells us rate and depth of
breathing, speed of expiration, rate of oxygen consumption.
• Spirometry — measurement of pulmonary function. Aids diagnosing lung
disorders that are restrictive vs. obstructive disorders.
Restrictive disorder — any disorder where lungs are limited in amount of air
that can be inflated (inability to inflate and bring air in)
Pulmonary Fibrosis — scarring of lungs. Tuberculosis, black lung.
Can’t inflate and bring in as much air as usual.
Obstructive disorder — interfere air flow by restricting or blocking airway so
limits amount of air that can inhaled or exhaled.
Example — asthma, chronic bronchitis
Emphysema — both restrictive and obstructive.
Pulmonary measurements
Proportional to body size, so values generally higher in males than females.
Volumes
• Tidal Volume — amount of air inhaled or exhaled in one breath during
quiet breathing. About 500 mL.
• Inspiratory Reserve Volume (IRV) = VC - (TV + ERV). 3000 mL
in males.
