- volume of air inhaled &/or exhaled at rest
- "normal breathing pattern"
VC = vital capacity
- MAXIMAL volume of air a person can expire after a maximal inspiration
- "after a normal exhalation, breathe IN as deeply as possible and then exhale as much as possible"
vital capacity is an indicator of??
- RESTRICTIVE LUNG DISEASE
- ex: pulmonary fibrosis where VC is reduced
FVC = forced vital capacity
- maximal volume of air a person can expire FORCEFULLY after a MAXIMAL inspiration
- "after a normal exhalation, breathe IN as deeply as possible & then exhale FORCEFULLY as much as possible"
FVC can be an indicator of ???
- RESTRICTIVE LUNG DISEASE
FEV1 = forced expiratory volume
- the volume of air that a person can forcibly EXPIRE in ONE second
FEV1 is an indicator of??
- obstructive lung disease
- ex: asthma where passageways are blocked/reduced in diameter
- normal respiration
- cessation of breathing
- abnormal increase in depth & rate of breathing
- difficult or labored breathing
- increased respiratory rate
- excessively rapid respiratory rate
- total lack of oxygen
- excess CO2 in the blood
- lack of oxygen resulting in death
- collapse of the alveoli
- respiratory passages where gas exchange does NOT occur
application question: describe how the diaphragm contributes to lung ventilation.
- when diaphragm contracts (dome descends), volume of thoracic cavity INCREASES
- pleura follows as well as lung tissue
- INCREASES volume of alveoli & REDUCES pressure
- pressure gradient set up from OUTSIDE to INSIDE
application question: identify several muscles used in FORCED inhalation.
application question: define the term dead space with respect to the respiratory system.
- includes those portions of the respiratory system that do NOT exchange gases with the blood
- i.e. trachea & major bronchi
application question: why were your respiratory volume measurements corrected with the BTPS factor?
- BTPS (body temperature, atmospheric pressure, saturated w/ water vapor) factor used b/c volumes measured are in the spirometer (at room temperature) & air is DRY
- in lungs the air is at body temperature & IS saturated with water, thus INCREASING the volume of the air
application question: distinguish between obstructive & restrictive pulmonary diseases. how does spirometry aid in their diagnosis?
- obstructive lung disease = result from blockage or narrowing of air passageways (values such as FEV1 allow clinicians to determine whether or not air flow is NORMAL)
- restrictive lung disease = result in a reduction in functional lung tissue (values such as VITAL CAPACITY & FORCED VITAL CAPACITY) help to determine if an individual has the normal amount of functional lung tissue
application question: why does the rate of oxygen consumption increase DURING exercise?
- demands of increased metabolism in tissues, such as muscle, DICTATE
application question: why does the rate of oxygen consumption remain elevated AFTER exercise?
- substances such as lactic acid MUST be metabolized & also the INCREASED heat generated by exercise drives up metabolic reactions
application question: how might HYPERventilation & HYPOventilation affect the pH of the blood?
- HYPER = drives off CO2 & REDUCE [H+] in the blood ; increases pH
- HYPO = INCREASES CO2 & drives up [H+] in the blood ; reduces pH