15.2 Mechanism of Breathing
(Source: www.biologycorner.com )
Introduction to Respiratory System
Primary Function: obtaining _____________ and removing
_____________ _____________
Other functions: _____________ air, produce sounds, sense of smell,
_____________ of blood _____________
Respiration: the process of gas _____________ between the
_____________ and body _____________
Parts of Respiration:
1. Movement of air into the lungs – _____________
2. Gas exchange between _____________ and _____________
(_____________ respiration)
3. Gas _____________ in blood
4. Gas exchange between the _____________ and body
_____________ ( _____________ respiration)
Cellular Respiration – the process of _____________ use and CO2
_____________ at the _____________ level
RESPIRATORY AIR VOLUMES AND CAPACITIES
_______________________
– measures volumes of air moving in and out of the
lungs.
4 distinct respiratory _______________________
Respiratory cycle – 1 _______________________ + the following
_______________________
1. Resting _______________________l volume – amount of air that enters
the lungs during 1 cycle
2. Inspiratory and
_______________________ volume – after
_______________________ inhalation or exhalation
_______________________ Volume – air _______________________
lungs even after _______________________ exhalation
3. Expiratory
4.
in the
Combining two or more of the respiratory volumes = respiratory
_______________________.
1. _______________________ Reserve Volume + Expiratory
_______________________ Volume + Tidal _______________________ = Vital
_______________________ (maximum amount of air a person can
_______________________)
2. Tidal Volume + Inspiratory Reserve Volume = _______________________
Capacity (max amount that can be _______________________)
3. _______________________ Reserve Volume + Residual Volume =
Functional _______________________Capacity (volume that
_______________________ in the lungs, _______________________)
4. Vital _______________________ + Residual Volume =
_______________________ Lung Capacity (varies by sex, age, body size)
INSPIRATION AND EXPIRATION
Inspiration = _______________________
_______________________
= exhalation
Steps of Inspiration/Inhalation:
1. The _______________________ moves _______________________ and the
atmospheric pressure in the _______________________ falls, which forces
air into the airways
2. External _______________________ muscles contract,
______________________ ribs and sternum and _______________________
the cavity even more (Intercostal muscles are the muscles that cover
and are between your ribs.)
3. Pleural ___________________ held tightly together, move with the
____________________ of muscles
4. Surface ______________ in the alveoli (caused by water) makes it
difficult to _______________ them. ________________ reduces
tendency of alveoli to collapse. (Lack or surfactant in preemies can
cause respiratory distress)
5. A _______________ breath can be achieved through other muscles:
___________________ minor and sternocleidomastoid
6. The ____________ breath of a ________________ is the hardest
because all of the alveoli are only _____________ inflated.
*Since our breathing is based on _________________ pressure (and the
difference in the pressure in the lungs), if there is a hole in the pleural
cavity, the lung _________________ (deflates). This can happen if a
person is stabbed or a broken rib pierces the lung.
Steps of Expiration/Exhalation:
1. As diaphragm and other muscles ____________, elastic recoil from
surface _______________ forces air out
2. If a person needs to exhale more air, ________________ (expiratory)
intercostals muscles _________________. Abdominal ___________
muscles (internal and external ______________, rectus abdominus
and transverses _____________) can help squeeze out more air.
3. These contractions increase the air pressure within the
______________ cavity, forcing air _________
NON-RESPIRATORY MOVEMENTS
Used to clear air passageways (coughing, sneezing) or express emotion
(laughter, crying)
Result from reflexes –
A _____________ is a sudden _______________ due to a ________
of the _________________, air striking vocal __________ makes the
sound
A __________ may be caused by not enough __________ becoming
oxygenated, a yawn forces a __________ breath
Measuring Lung Capacity
(Source: http://www.biologycorner.com/worksheets/lungcapacity.html)
The amount of air that you move in and out of your lungs while breathing normally is called TIDAL VOLUME. This
amount of air provides enough oxygen for a person who is resting. It is possible to inhale and exhale more forcefully the maximum amount of air moved in and out of the lungs is called the VITAL CAPACITY. In this activity, you will be
measuring the vital capacity and the tidal volume of your own lungs, this actual number can then be compared with a
number derived from an equation that measures vital capacity. In effect, you are measuring an actual number, based
on laboratory measurements, to a theoretical number, based on an equation. If you have any breathing difficulties
(asthma or other condition), you should not participate in this activity, instead only take the data on your lab partner or
group.
Materials - Balloons, metric ruler, meter stick, bathroom
scale (optional)
How to Take Measurements with a Balloon
1. Measuring Tidal Volume -- Stretch a round balloon several
times to stretch it out. Inhale normally and then exhale
normally into the balloon. Do not force your breathing. Pinch
the end of the balloon and measure its diameter. Repeat this
so that you have 3 total measurements and can take the
average and record in the data table.
2. Measuring Vital Capacity - Repeat the procedure, only this
time inhale as much air as you can and exhale forcefully.
Record three measurements in the data table.
3. Convert the diameters to a volume using the graph and
record this in your table.
4. Estimated Vital Capacity
Research has shown that the
capacity of a person's lungs is
proportional to the surface area
of his or her body. To find the
surface area, you will need to
know your height and weight. There are a couple of different ways to calculate your body surface area
mathematically. Either use the equation below or go to a website that has an automatic calculator. (A google search
on "body surface area calculator will yield many pages that have these calculators)
Once you have calculated your surface area, a second equation will calculate your estimated vital capacity.
Males: SA x 2500
Females SA x 2000
DATA TABLE
Tidal Volume
Balloon
Diameter
Trial
1
2
3
Volume
(from graph)
Vital Capacity
Balloon
Diameter
Estimated Vital Capacity
Volume
(from graph)
Height (cm)
Mass (kg)
Surface Area
Vital Capacity
Average
ANALYSIS
1. Why is it important to measure tidal volume and vital capacity three times and then get an average?
2. Compare your data to other members of the class. How can you account for differences?
3. How does your measured vital capacity compare to the vital capacity you estimated using the formula? Which do
you think is more accurate and why?
4. How might an athlete's vital capacity compare to a non-athlete? Explain your reasoning.
APPLICATION
1. Examine the data table of a person who entered into a training program. This person's vital capacity was measured
over a 60 day period. Use the data to construct a graph
DATA
GRAPH
Day of Training
Vital Capacity
0
4800
10
4840
20
4890
30
4930
40
4980
50
5180
60
5260
2. What happened to the person's vital capacity over the course of the training period?
3. What probably caused the change?
4. How might vital capacity be important to a musician?
15.2 Mechanism of Breathing
Introduction to Respiratory System
Primary Function: obtaining oxygen and removing carbon dioxide
Other functions: Filter air, produce sounds, sense of smell, regulation of blood pH
Respiration: the process of gas exchange between the atmosphere and body cells
1.
2.
3.
4.
Movement of air into the lungs – Ventilation
Gas exchange between blood and air (external respiration)
Gas transport in blood
Gas exchange between the blood and body cells (internal respiration)
Cellular Respiration – the process of oxygen use and CO2 production at the cellular
level
RESPIRATORY AIR VOLUMES AND CAPACITIES
Spirometry – measures volumes of air moving in and out of the lungs. 4 distinct
respiratory volumes
Respiratory cycle – 1 inspiration + the following expiration
1. Resting Tidal volume – amount of air that enters the lungs during 1 cycle
2. Inspiratory and 3. Expiratory reserve volume – after forced inhalation or exhalation
4. Residual Volume – air remaining in the lungs even after forceful exhalation
*** Combining two or more of the respiratory volumes = respiratory capacities.
Inspiratory Reserve Volume + Expiratory Reserve Volume + Tidal Volume = Vital
Capacity (maximum amount of air a person can exhale)
Tidal Volume + Inspiratory Reserve Volume = Inspiratory Capacity (max amount that
can be inhaled)
Expiratory Reserve Volume + Residual Volume = Functional Residual Capacity (volume
that remains in the lungs, resting)
Vital Capacity + Residual Volume = Total Lung Capacity (varies by sex, age, body size)
INSPIRATION AND EXPIRATION
Inspiration = inhalation | Expiration = exhalation
1. The diaphragm moves downward and the atmospheric pressure in the alveoli falls,
which forces air into the airways
2. External intercostals muscles contract, raising ribs and sternum and enlarges the
cavity even more
3. Pleural membranes held tightly together, move with the contractions of muscles
4. Surface tension in the alveoli (caused by water) makes it difficult to inflate them.
Surfactant reduces tendency of alveoli to collapse. (Lack or surfactant in preemies can
cause respiratory distress)
5. A deeper breath can be achieved through other muscles – pectoralis minor and
sternocleidomastoid
6. The first breath of a newborn is the hardest because all of the alveoli are only partially
inflated.
*Since our breathing is based on atmospheric pressure (and the difference in the
pressure in the lungs), if there is a hole in the pleural cavity, the lung collapses
(deflates). This can happen if a person is stabbed or a broken rib pierces the lung.
*Since our breathing is based on atmospheric pressure (and the difference in the
pressure in the lungs), if there is a hole in the pleural cavity, the lung collapses
(deflates). This can happen if a person is stabbed or a broken rib pierces the lung.
EXHALATION
1. As diaphragm and other muscles relax, elastic recoil from surface tension forces air
out
2. If a person needs to exhale more air, internal (expiratory) intercostals muscles
contract. Abdominal wall muscles (internal and external obliques, rectus abdominus and
transverses abdominus) can help squeeze out more air.
3. These contractions increase the air pressure within the pleural cavity, forcing air out
NON-RESPIRATORY MOVEMENTS - Used to clear air passageways (coughing,
sneezing) or express emotion (laughter, crying) – result from reflexes -- A hiccup is a
sudden inspiration due to a spasm of the diaphragm, air striking vocal folds makes the
sound ---A yawn may be caused by not enough blood becoming oxygenated, a yawn
forces a deep breath