Breathing & Exchange of Gases PPT Biology Class 11

 Page 1


RESPIRATORY ORGANS
• Lower invertebrates like sponges, coelenterates, 
flatworms, etc., exchange O2 with CO2 by simple 
diffusion over their entire body surface.
• Earthworms use their moist cuticle
• insects have a network of tubes (tracheal tubes) 
to transport atmospheric air within the body.
• Special vascularised structures called gills
(branchial respiration) are used by most of the 
aquatic arthropods and molluscs
• vascularised bags called lungs (pulmonary
respiration) are used by the terrestrial forms for 
the exchange of gases.
Page 2


RESPIRATORY ORGANS
• Lower invertebrates like sponges, coelenterates, 
flatworms, etc., exchange O2 with CO2 by simple 
diffusion over their entire body surface.
• Earthworms use their moist cuticle
• insects have a network of tubes (tracheal tubes) 
to transport atmospheric air within the body.
• Special vascularised structures called gills
(branchial respiration) are used by most of the 
aquatic arthropods and molluscs
• vascularised bags called lungs (pulmonary
respiration) are used by the terrestrial forms for 
the exchange of gases.
Page 3


RESPIRATORY ORGANS
• Lower invertebrates like sponges, coelenterates, 
flatworms, etc., exchange O2 with CO2 by simple 
diffusion over their entire body surface.
• Earthworms use their moist cuticle
• insects have a network of tubes (tracheal tubes) 
to transport atmospheric air within the body.
• Special vascularised structures called gills
(branchial respiration) are used by most of the 
aquatic arthropods and molluscs
• vascularised bags called lungs (pulmonary
respiration) are used by the terrestrial forms for 
the exchange of gases.
Human Respiratory System
Nasal Passage
Pharynx
Larynx
Trachea
Bronchi
Page 4


RESPIRATORY ORGANS
• Lower invertebrates like sponges, coelenterates, 
flatworms, etc., exchange O2 with CO2 by simple 
diffusion over their entire body surface.
• Earthworms use their moist cuticle
• insects have a network of tubes (tracheal tubes) 
to transport atmospheric air within the body.
• Special vascularised structures called gills
(branchial respiration) are used by most of the 
aquatic arthropods and molluscs
• vascularised bags called lungs (pulmonary
respiration) are used by the terrestrial forms for 
the exchange of gases.
Human Respiratory System
Nasal Passage
Pharynx
Larynx
Trachea
Bronchi
• During swallowing glottis can be covered by a 
thin elastic cartilaginous flap called epiglottis to 
prevent the entry of food into the larynx.
• Each bronchi undergoes repeated divisions to 
form the secondary and tertiary bronchi and 
bronchioles ending up in very thin terminal 
bronchioles. 
• The tracheae, primary, secondary and tertiary 
bronchi, and initial bronchioles are supported by 
incomplete cartilaginous rings. 
• Each terminal bronchiole gives rise to a number 
of very thin, irregular-walled and vascularised
bag-like structures called alveoli. 
• The branching network of bronchi, bronchioles 
and alveoli comprise the lungs
Page 5


RESPIRATORY ORGANS
• Lower invertebrates like sponges, coelenterates, 
flatworms, etc., exchange O2 with CO2 by simple 
diffusion over their entire body surface.
• Earthworms use their moist cuticle
• insects have a network of tubes (tracheal tubes) 
to transport atmospheric air within the body.
• Special vascularised structures called gills
(branchial respiration) are used by most of the 
aquatic arthropods and molluscs
• vascularised bags called lungs (pulmonary
respiration) are used by the terrestrial forms for 
the exchange of gases.
Human Respiratory System
Nasal Passage
Pharynx
Larynx
Trachea
Bronchi
• During swallowing glottis can be covered by a 
thin elastic cartilaginous flap called epiglottis to 
prevent the entry of food into the larynx.
• Each bronchi undergoes repeated divisions to 
form the secondary and tertiary bronchi and 
bronchioles ending up in very thin terminal 
bronchioles. 
• The tracheae, primary, secondary and tertiary 
bronchi, and initial bronchioles are supported by 
incomplete cartilaginous rings. 
• Each terminal bronchiole gives rise to a number 
of very thin, irregular-walled and vascularised
bag-like structures called alveoli. 
• The branching network of bronchi, bronchioles 
and alveoli comprise the lungs