BREATHING AND EXCHANGE OF GASES
BREATHING The process of exchanging oxygen from the
atmosphere with carbon dioxide produced by
the cell is called
breathing
Oxygen is utilised by organisms to indirectly
break down simple molecules
Mechanism of
breathing vary among different groups
animals
depending mainly on
their habitats and
of
levels of organisation
ORGANISMS MECHANISM
Sponges
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A pairofnostrils
PHARYNX common for food masaintmilliessage
passage
and air
pharynx
LARYNX cartilaginous box asinn
ep oFdS helps in sound production
also called sound box tratica
µ
opening of larynx is glotis Brittani B 8Eni
4 glottis is covered by thin elastic primary Bronchi
PrimtryBronchi
flap calledepiglottis
cartilaginous secondaryBronchi Secondary Bronchi
to prevent the entry offoodinto btronchi Tertiary
bEonchi
tertiary
Larynx initial brischioles initial
broInchioles
Terminal bronchioles Terminal bronchioles
TRACHEA straight tube aneol
extend to the midthoracic
up avoid
cavity
divides at the level
of 5ᵗʰ thoracic vertebra into a right
and left primary bronchi
each bronchi undergoes repeated divisions to
BRONCHI form primary
secondary tertiary initial and verythin terminal bronchioles
The trachea primary secondary tertiarybronchi and initial bronchiole
are supported by incomplete cartilaginous rings
Each terminal bronchioles give rise to a number
of very thin
irregular walled and vascularised like structure called
bag
Evel
LUNGS The branching network of bronchi bronchioles and alveoli
comprises lungs
Lungs are paired structure
situated in thoracic cavity
PLEURA
Lungs are covered by double layered pleura with
pleural fluid between them
, Pleural fluid reduces friction on
lung surface
Outer in close contact with the thoraci
Pleural membrane lining
inner in contact with the
lungsurfac
Geo Epiglottis
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CONDUCTING PART The with the external nostrils
parts starting
to the terminal bronchioles constitute the
up
conducting part
Fincham transports the atmospheric air to alveoli
cleans the atmospheric air from
foreign particles
humidifies atmospheric air
brings the atmospheric air to bodytemperature
, EXCHANGEPART the alveoli and their ducts form the exchangepart
Functionn it is the site of actual diffusion of O2andCO2 between bloodan
atmospheric air
THORACIC CHAMBER formed
dorsally vertebral column
ventrally sternum
laterally ribs
On lower side dome shaped
diaphragm
The anatomical setup of lungs in thorax is such
that in the volume thoracic cavity
any change
will be reflected in
of
lungcavity
the
This arrangemtent is essential for
breathing
STEPS OF RESPIRATION
1 Pulmonary ventilation
2 Diffusion of gases across alveolar membrane
3 Transport of gases by the blood
4 Diffusion
of gases between blood and tissues
5 Utilisation
of oxygen by the cellsfor catabolic reactions and
resultant release of carbondioxide
MECHANISM OF BREATHING
INSPIRATION EXPIRATION
Occur ifthe pressure within the occur if the intra pulmonarypressure
intra pulmonary pressure is is higher than the atmospheric
lungs
less than the atmospheric pressure pressure
i.e Diaphragm relaxed
dome shaped
Diaphragm contracts flatshape
increases the volume of thoracic
chamber in antero posterioraxis
Inter costal muscles contract Inter costal muscles relax
,
, increase the
Humans can
strength of both inspiration
and expiration with the help of additional muscles in the
abdomen
On an
average
a healthy human breathes 12 16 times minute
SPiROMEERL used to measure the volume of air involved in breathing
movements
helps in the clinical assessment of pulmonary functions
Residual volume cannot be measured
by spirometer
RESPIRATORY VOLUMES AND CAPACITIES
Tidalvolume TV volume of air inspired or expired
during a approx 500 ml
normal respiration
Inspiratory Additional volume of air a person can inspire 2500mL to 3000mL
Reserley
olume by forcible inspiration
Expiratory Additional volume of air a person can expire 1000mL to 1100mL
a
Reseyjolume by forcible expiration
Residual volume of air remaining in the
lungs 1100mL to 1200mL
volume pay even
after a forcible expiration
Inspiratory total
of air a person can
volume
TV IRY
Capacity IC inspire after normal expiration
Total volume air a
Expiratory of person can TV ERY
capacity EC expire after a normal inspiration
FunctionalResidual Volume of air accommodated in the ER RY
capacity FRC
Lungs after a normal expiration
VitalCapacity VC Themaximumvolume of air a person can ERV TV IRV
breath in after a forcedexpiration
Total Lung Total volume of air accommodated in the
lungs at RV ERV TV IRV
Capacity TLC the end of a forced inspiration y pay
, EXCHANGE OF GASES
Primary sites for exchange of
9
Gaseous exchange take place by siEe.ec Tfftnmainly based on pressure
concentration gradient
Factors affecting rate
ofdiffusion
stiffly of carbon dioxide is 20 25times higher than that of
the oxygen the amount of CO2 that can diffuse through the
diffusion membrane perunit difference in partial pressure is
much higher compared to that of oxygen
Iessmofthemembrane The total thickness of the diffusion
membrane in human lungs is much less than a millimetre
Diffusion membrane is made three
up of layers
1 the thin squamous epithelium of alveoli
2 the endothelium of alveolar capillaries
3 the basement substance in between the above layers
Partial Pressure Partial pressure is contributed by an individual
in a mixture of gases is called partial pressure
gas
Respiratory Atmospheric Alveoli Blood Blood s s
Gas air Deoxygenated oxygenated
02 159 104 40 95 40
CO2 0.3 40 45 40 45
Partial pressures in mmHg of O2 and CO2 at different parts
,
, HAEMOGLOBIN it is a red coloured iron containing pigment presentin theRBCs
Each haemoglobin molecule can carry a maximum offourmolecules
of oxygen
Oxygen can bind with haemoglobin in a reversible manner to form
ony
haemoglobin
Binding of oxygen with haemoglobin is primarily related to partial
pressure of oxygen pos
Oxygen Dissociation Curve
In the alveoli the factors is
80
ÉÉ
favourablefor the formation MMM
are
of Oxyhaemoglobin
1 high PO2 a
2 Low por ÉTÉ
o so stateroom
3 Lesser concentration of H Pa t
4 Lower temperature fe1eg
oxygen dissociation curve
Every 100mL blood can deliver around 5mL of
of oxygenated
oxygen to the tissues under normal physiological conditions
TRANSPORT OF CARBON DIOXIDE
Transport of Co2 from tissue to RBCs as carbaminohaemoglobin 2m25
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2 www.agggaaeggia
Hbo 02 the on Hb.cat 2
Tissue RBC
, Transport of CO2from tissue to alveoli through plasma in a dissolved
state 7
CO2
Maggght
t
MdStsssossossstt Plasma
Tissue L Bloodvessel
Transport of CO2 from tissue to alveoli as bicarbonate ions 70
The binding of carbon dioxide with haemoglobin is affected by p02
In tissues the factors favourable for the formation of
carbamino haemoglobin are
1 LOW PO2
2
high p 02
3 concentration of H
higher
4
high temperature
Eison ann.fra an minientiuiii.ie tofEne a'mEi's
present
in the plasma too
RBCs
Stef Transport of CO2 to
Tissue will
go in
plasma
Tetrahedral no Eisisses Hug Effise Hos H
CO2
02 HHD Hb
a
songthese RBC
BREATHING The process of exchanging oxygen from the
atmosphere with carbon dioxide produced by
the cell is called
breathing
Oxygen is utilised by organisms to indirectly
break down simple molecules
Mechanism of
breathing vary among different groups
animals
depending mainly on
their habitats and
of
levels of organisation
ORGANISMS MECHANISM
Sponges
fi
ameratesana ifeng.hamdk669 fifffiffffffffffffffffffffiffhassi
flatworms
Earthworms Moist skin nnI.at
na iri
cutaneous nosfTffTffF'thirst.iro
frogs www
Insects Airsacs
Tracheal tubes
fff If
otFfItIItFF
rssF
fFg
m.IE
ggo
t
9
998
aaa 9.9
Faattttaai
Aquatic arthropods Gills
m and Branchial
FF
Ff
ffffFF
F
FffffffF
fIsFFFffaff
amphibians reptiles
and mammals and ffiiÉiffÉI
Pulmonary ftfiff
offf
Ylff fMoafihffff
Ffooo
, EFFaIEEtrdansysentw
A pairofnostrils
PHARYNX common for food masaintmilliessage
passage
and air
pharynx
LARYNX cartilaginous box asinn
ep oFdS helps in sound production
also called sound box tratica
µ
opening of larynx is glotis Brittani B 8Eni
4 glottis is covered by thin elastic primary Bronchi
PrimtryBronchi
flap calledepiglottis
cartilaginous secondaryBronchi Secondary Bronchi
to prevent the entry offoodinto btronchi Tertiary
bEonchi
tertiary
Larynx initial brischioles initial
broInchioles
Terminal bronchioles Terminal bronchioles
TRACHEA straight tube aneol
extend to the midthoracic
up avoid
cavity
divides at the level
of 5ᵗʰ thoracic vertebra into a right
and left primary bronchi
each bronchi undergoes repeated divisions to
BRONCHI form primary
secondary tertiary initial and verythin terminal bronchioles
The trachea primary secondary tertiarybronchi and initial bronchiole
are supported by incomplete cartilaginous rings
Each terminal bronchioles give rise to a number
of very thin
irregular walled and vascularised like structure called
bag
Evel
LUNGS The branching network of bronchi bronchioles and alveoli
comprises lungs
Lungs are paired structure
situated in thoracic cavity
PLEURA
Lungs are covered by double layered pleura with
pleural fluid between them
, Pleural fluid reduces friction on
lung surface
Outer in close contact with the thoraci
Pleural membrane lining
inner in contact with the
lungsurfac
Geo Epiglottis
ᵗᵗÉ
ᵗ
ᵗ
Larynx
trachea
É dd
Eᵈᵈᵈ
a
magnan
ffÉÉÉlf
fÉfff
Fff
ᵗÉ
ÉÉÉ
ffffff
ÉÉ
dfffidcffffff.hn
f
f
fÉfftff
j
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ÉÉ j
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h ff f
É
f
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ÉÉÉÉÉ
ffg IÉv
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Broncmsfggggagggff p
ng ÉfÉÉÉÉffÉgjgÉ
ÉÉÉÉÉfÑLfg
fg
f
lff
fÉ
poet I f
am
than Remeatory systemm
CONDUCTING PART The with the external nostrils
parts starting
to the terminal bronchioles constitute the
up
conducting part
Fincham transports the atmospheric air to alveoli
cleans the atmospheric air from
foreign particles
humidifies atmospheric air
brings the atmospheric air to bodytemperature
, EXCHANGEPART the alveoli and their ducts form the exchangepart
Functionn it is the site of actual diffusion of O2andCO2 between bloodan
atmospheric air
THORACIC CHAMBER formed
dorsally vertebral column
ventrally sternum
laterally ribs
On lower side dome shaped
diaphragm
The anatomical setup of lungs in thorax is such
that in the volume thoracic cavity
any change
will be reflected in
of
lungcavity
the
This arrangemtent is essential for
breathing
STEPS OF RESPIRATION
1 Pulmonary ventilation
2 Diffusion of gases across alveolar membrane
3 Transport of gases by the blood
4 Diffusion
of gases between blood and tissues
5 Utilisation
of oxygen by the cellsfor catabolic reactions and
resultant release of carbondioxide
MECHANISM OF BREATHING
INSPIRATION EXPIRATION
Occur ifthe pressure within the occur if the intra pulmonarypressure
intra pulmonary pressure is is higher than the atmospheric
lungs
less than the atmospheric pressure pressure
i.e Diaphragm relaxed
dome shaped
Diaphragm contracts flatshape
increases the volume of thoracic
chamber in antero posterioraxis
Inter costal muscles contract Inter costal muscles relax
,
, increase the
Humans can
strength of both inspiration
and expiration with the help of additional muscles in the
abdomen
On an
average
a healthy human breathes 12 16 times minute
SPiROMEERL used to measure the volume of air involved in breathing
movements
helps in the clinical assessment of pulmonary functions
Residual volume cannot be measured
by spirometer
RESPIRATORY VOLUMES AND CAPACITIES
Tidalvolume TV volume of air inspired or expired
during a approx 500 ml
normal respiration
Inspiratory Additional volume of air a person can inspire 2500mL to 3000mL
Reserley
olume by forcible inspiration
Expiratory Additional volume of air a person can expire 1000mL to 1100mL
a
Reseyjolume by forcible expiration
Residual volume of air remaining in the
lungs 1100mL to 1200mL
volume pay even
after a forcible expiration
Inspiratory total
of air a person can
volume
TV IRY
Capacity IC inspire after normal expiration
Total volume air a
Expiratory of person can TV ERY
capacity EC expire after a normal inspiration
FunctionalResidual Volume of air accommodated in the ER RY
capacity FRC
Lungs after a normal expiration
VitalCapacity VC Themaximumvolume of air a person can ERV TV IRV
breath in after a forcedexpiration
Total Lung Total volume of air accommodated in the
lungs at RV ERV TV IRV
Capacity TLC the end of a forced inspiration y pay
, EXCHANGE OF GASES
Primary sites for exchange of
9
Gaseous exchange take place by siEe.ec Tfftnmainly based on pressure
concentration gradient
Factors affecting rate
ofdiffusion
stiffly of carbon dioxide is 20 25times higher than that of
the oxygen the amount of CO2 that can diffuse through the
diffusion membrane perunit difference in partial pressure is
much higher compared to that of oxygen
Iessmofthemembrane The total thickness of the diffusion
membrane in human lungs is much less than a millimetre
Diffusion membrane is made three
up of layers
1 the thin squamous epithelium of alveoli
2 the endothelium of alveolar capillaries
3 the basement substance in between the above layers
Partial Pressure Partial pressure is contributed by an individual
in a mixture of gases is called partial pressure
gas
Respiratory Atmospheric Alveoli Blood Blood s s
Gas air Deoxygenated oxygenated
02 159 104 40 95 40
CO2 0.3 40 45 40 45
Partial pressures in mmHg of O2 and CO2 at different parts
,
, HAEMOGLOBIN it is a red coloured iron containing pigment presentin theRBCs
Each haemoglobin molecule can carry a maximum offourmolecules
of oxygen
Oxygen can bind with haemoglobin in a reversible manner to form
ony
haemoglobin
Binding of oxygen with haemoglobin is primarily related to partial
pressure of oxygen pos
Oxygen Dissociation Curve
In the alveoli the factors is
80
ÉÉ
favourablefor the formation MMM
are
of Oxyhaemoglobin
1 high PO2 a
2 Low por ÉTÉ
o so stateroom
3 Lesser concentration of H Pa t
4 Lower temperature fe1eg
oxygen dissociation curve
Every 100mL blood can deliver around 5mL of
of oxygenated
oxygen to the tissues under normal physiological conditions
TRANSPORT OF CARBON DIOXIDE
Transport of Co2 from tissue to RBCs as carbaminohaemoglobin 2m25
assortterosannannonrananagong
2 www.agggaaeggia
Hbo 02 the on Hb.cat 2
Tissue RBC
, Transport of CO2from tissue to alveoli through plasma in a dissolved
state 7
CO2
Maggght
t
MdStsssossossstt Plasma
Tissue L Bloodvessel
Transport of CO2 from tissue to alveoli as bicarbonate ions 70
The binding of carbon dioxide with haemoglobin is affected by p02
In tissues the factors favourable for the formation of
carbamino haemoglobin are
1 LOW PO2
2
high p 02
3 concentration of H
higher
4
high temperature
Eison ann.fra an minientiuiii.ie tofEne a'mEi's
present
in the plasma too
RBCs
Stef Transport of CO2 to
Tissue will
go in
plasma
Tetrahedral no Eisisses Hug Effise Hos H
CO2
02 HHD Hb
a
songthese RBC
