Upload
brianne-wright
View
220
Download
0
Tags:
Embed Size (px)
Citation preview
UNIT
2The nutrition function
Natural Science 2. Secondary Education
RESPIRATION IN DIFFERENT ANIMALS
UNIT
2What is diffusion?
• Diffusion is the transfer of gases between the external environment and the circulating liquid, through tissues that are thin enough to allow these gases to pass.
• When the circulating liquid reaches the respiratory organs, it is carbon dioxide-rich and oxygen-poor. When air reaches the respiratory organs, on the other hand, it is oxygen-rich and carbon dioxide-poor.
• This is when diffusion occurs: oxygen will move from the area of high concentration to the area of low concentration (from the air to the circulating liquid), and carbon dioxide will do the same (it will move from the circulating liquid to the air).
Diffusion in living things
Air with O2
Air with CO2
Blood with O2
Blood with CO2 O2
CO2
Exchange tissue
Natural Science 2. Secondary Education
UNIT
2What is diffusion?
• Diffusion can occur:
Diffusion in living things
• Through the body surface. This occurs in sponges, polyps, worms and some amphibians.
• Through gills: This occurs in molluscs, crustaceans, fish and some amphibians.
• Through tracheae: In insects.
• Through lungs: In amphibians, reptiles, birds and mammals.
Natural Science 2. Secondary Education
UNIT
2
RESPIRATIONIN WATER
THROUGH THE BODY SURFACE
THROUGHGILLS
Click on each box to find out more
How some animals take oxygen from the water
is carried out
Natural Science 2. Secondary Education
UNIT
2• This is seen in animals that live underwater or in very wet environments, like the soil.
• Sponges, cnidarians (polyps and jellyfish), worms and some amphibians absorb air in this way.
Respiration through the body surface
The animal absorb O2 through its surface
The animal eliminates CO2 through its surface
O2 O2CO2 CO2
Respiration through the body surface in an annelid.
Go back to the Start menu
Wetenvironment
Bodysurface
How some animals take oxygen from the water
Natural Science 2. Secondary Education
UNIT
2• Gills are very thin sheets or filaments full of capillaries.
• When water passes through the gills, carbon dioxide from the circulating liquid inside the organism is exchanged for oxygen from the water.
• Gills are the respiratory organs of aquatic molluscs, crustaceans, fish and some amphibians.
Respiration through gills
Blood with O2 Blood with CO2
Water
Water with O2
Water with CO2 Respiration through
gills in a fish.
O2
CO2
How some animals take oxygen from the water
Go back to the Start menuNatural Science 2. Secondary Education
UNIT
2
RESPIRATIONIN AIR
THROUGHTRACHEAE
THROUGHLUNGS
Click on each box to find out more
How some animals take oxygen from the air
is carried out
Natural Science 2. Secondary Education
UNIT
2• This type of respiration occurs in almost all insects.
• Tracheae are very thin tubes that branch out to provide the animal’s tissues with oxygen.
• They lead out of the body through pores called spiracles.
Respiration through tracheae
CO2
O2
Spiracle
TracheaThe insect’s tissues
Exoskeleton
Respiration through tracheae in an insect.
How some animals take oxygen from the air
Go back to the Start menuNatural Science 2. Secondary Education
UNIT
2• This type of respiration occurs in amphibians, reptiles, birds and mammals.
• Lungs are made up of millions of tiny tubes or cavities called alveoli, which are full of capillaries. This is where oxygen passes into the blood.
• Lungs are connected to the external environment by the rest of the respiratory tract (airways).
Respiration through lungs
Blood with O2
Blood with CO2
O2
CO2
Respiration through lungs in a mammal.
Lungs
Airways
How some animals take oxygen from the air
Go back to the Start menuNatural Science 2. Secondary Education