biol 66 lab 11

lung volume, terms to know, etc.

V(t) = tidal volume

- 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

eupnea

- normal respiration

apnea

- cessation of breathing

hyperpnea

- abnormal increase in depth & rate of breathing

dyspnea

- difficult or labored breathing

polypnea

- increased respiratory rate

tachypnea

- excessively rapid respiratory rate

anoxia

- total lack of oxygen

hypercapnia

- excess CO2 in the blood

asphyxia

- lack of oxygen resulting in death

atelectasis

- collapse of the alveoli

dead space

- 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.

- abdominal muscles
- neck muscles (scalenes & sternocleidomastoid)

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