tidal volume (TV)
the amount of air that moves into or out of the lungs in one inspiration or expiration
resting tidal volume
amount of air that moves into or out of the lungs at rest
inspiratory reserve volume (IRV)
the amount of air you inspired above tidal volume
expiratory reserve volume (ERV)
the amount of air you expired beyond tidal volume
residual volume (RV)
the amount of air left in your lungs after a maximal expiration
-residual volume cannot be voluntarily removed
inspiratory capacity (IC)
the sum of tidal volume and inspiratory reserve volume
IC=TV+IRV
functional residual capacity (FRC)
the sum of expiratory reserve volume and residual volume
FRC=ERV+RV
vital capacity (VC)
the sum of inspiratory reserve volume, tidal volume, expiratory reserve volume
VC=IRV+TV+ERV
total lung capacity TLC
the sum of all volumes
TLC= IRV + TV + ERV+ RV
Tidal volume increases during exercise. Why does it need to be larger?
a larger tidal volume means more oxygen can be supplied to the active skeletal muscles and the increased amount of carbon dioxide produced by these muscles can be eliminated
forced vital capacity FVC
measures both the amount of air moved and the rate at which the air is moved
why is forced vital capacity a measure rather than a capacity?
because many respiratory diseases do not necessarily change the amount of air moved, but do change the rate of air movement
forced expiratory volume FEV
how much of forced vital capacity is exhaled in a given point of time
- FEV 1 is the amount of FVC exhaled in the first second of expiration, FEV2 is the first two seconds etc.
- FEV gives an indication of expiratory power and the overall resistance to air movement
why are FEV values not meaningful information between individuals?
- FEV values of a large person will be greater than those of a smaller person
- percentages can be compared
- percentage found by dividing FEV1/FVC
FEV percentages equation
FEV1/FVC
Jims FEV1 is 4 liters, whild Sarah’s is 3 liters. Does Jim have healthier lungs than Sarah? Why?
no, jim could possible just have larger lungs than Sarah
minute ventilation
the volume of air moving into or out of the respiratory tract in one minute
VR x Tv= minute ventilation
Ventilation rate (VR)
the number of breaths per minute
anatomic dead space
- nonalveolar parts of the respiratory tract
- nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles
in an adult anatomic dead space has a volume of around __ mL?
150 mL or .15 L
alveolar ventilation
the amount of air reaching the alveoli in one minute
AV= (TV-dead space) x VR
is it more valuble to know alveolar ventilation or minute ventilation ?
alveolar ventilation
why is it more important to know alveolar ventilation rather than minute ventilation?
aveolar ventilation give how much air is getting into the alveoli
what is the alveolar ventilation of a person with a TV or .5 L and a VR or 12 breaths per minute?
4.2liters/min
respiratory system function
- maintain correct conc. of oxygen and carbon dioxide in ECF
- phonation (speech production)
- regulating extracellular fluid pH
hyperventilation increases the amound of carbon dioxide eliminated from the body, and thus would result in an _________ ph of extracellular fluid.
increased pH
the pleural fluid within a pleural cavity acts as both a ______ and a ______.
lubricant and an adhesive
why is the adhesive action of pleural fluid important?
important in ventilation and prevents the lungs from collapsing, despite their natural elasticity
what structure do the slides and the water represent?
slides= pleaura
water=pleural fluid
costal arch
rib together with its costal cartilage
the posterior end of a rib is _______ to its anterior end
superior
ventilation is brought about by ____.
changes in the dimensions of the thoracic cavity
phenolphthalein is a pH indicator that is ____ in a basic solution and _______ in an acidic solution.
pink in a basic solution
clear in an acidic solution
more carbon dioxide was present in exhaled air at rest or after exercise?
more carbon dioxide was present in exhaled air after exercise
threshold
where the respiratory centers in your brain override your voluntary decision not to breath, forcing you to resume breathing
under which condition was CO2 concentration in the subjects ECF the lowest when he/she began holding his/her breath?
after hyperventilation because less co2 is in the ECF than normal, so it takes longer for the CO2 concentrations to reach threshold and for breathing to begin again
under which condition was CO2 concentration in the subjects ecf the highest when he/she began holding his/her breath?>
after exercise because the CO2 built up and she had to breath almost immediately after trying to hold her breath
