lecture 32 Flashcards
developmental process of respiration
- alveoli will increase from about 25 million at birth to more than 300 million. by 8 years of age
- conducting airways will grow steadily in diameter and length
adults breathe
12-18 cycles per minute
newborns
average 40-70 cycles per minute
5 year old
25 cycles per minute
respiratory flow
rate of flow of air in / out
volume
measured in liters, milileters, cubic cm
measuring respiration
respiratory flow, volume, capacity
quiet respiration
- 12-18 cycles of respiration per minute
- one cycle is 1/2 liter of air
- we process approximately 6-8 liters of air every minute
types of volume
- tidal volume
- inspiratory reserve volume
- expiratory reserve volume
- residual volume
- dead air
capacities
combination of volumes that express a physiological limit
types of capacities
vital capacity
functional residual capacity
inspiratory capacity
total lung capacity
what is tidal volume
volume of air we breathe in during a respiratory cycle (500 ml)
tidal volume varies as what
as a function of physical exertion, body size, and age
quiet tidal volume has an average for
adult males 600 cc
adult females 450 cc
fill up three 2 liter bottles in one minute
inspiratory reserve volume
- volume that can be inhaled after a tidal inspiration
- when breathing in and out, stop breathing at end of one of inspirations and instead of exhaling, breathe in as deeply as you can
- amount you inspired after you stopped is IRV - average is 2.475 liters
- 3100 ml
expiratory reserve volume
- amount of air that can be expired following passive, tidal expiration
- stop breathing right after you exhale, then expire as completely as you can
- ERV - average is 1 liter
- also referred to as resting lung volume - volume present in resting lungs after a passive exhalation
- 1200 ml
residual volume
- volume remaining in lungs after a maximum exhalation
- no matter how much you exhale, there ois a volume of air that cannot be eliminated - approx 1.1 liters
- does not exist in newborn
- 1200 ml
dead space air
- air in conducting passageways
- air that cannot undergo gas exchange
- adult has approx 1/10 of a liter
- associated w residual volume because it is air that cannot be expelled
vital capacity
- capacity available for speech
- combo of IRV, ERV. and TV
- represents total volume of air that can be inspired after a maximal expiration
- approx 4 liters in average adult
- 4800 ml
functional residual capacity
- volume of air remaining in body after passive exhalation
- ERV + RV
- approx 2.1 liter
- 2400 ml
total lung capacity
- sum of all of volumes
- approx 5.1 liters
- different from vital capacity because it includes RV which serves as a buffer in respiration in providing constant oxygenation when needed
- 6000 ml
inspiratory capacity
- maximum inspiratory volume possible after tidal expiration
- capacity of lungs for inspiration (TV + IRV)
- approx 3 liters for adults
- 3600 ml
what happens to vital capacity w age
as age increases, vital capacity decreases by about 0.1 liter per year in adulthood
vital capacity steadily increases w what
w body growth up to about age 20, stays stagnant through about 25 and then begins steady decline
