Download Gas exchange

Starter
Cells receive the substances
they need by diffusion and
osmosis
Diffusion
Oxygen in the blood
Net movement is down the
concentration gradient
Oxygen in the cells
Osmosis
Water in the soil
Net movement is down the
concentration gradient
Water inside a plant’s roots
Obtaining and transporting the
materials our bodies need / produce
How are organ systems specialised for
exchanging substances?
How does surface area influence the
exchange of food and oxygen?
How has the use of artificial aids to
breathing developed?
How are organ systems specialised for exchanging
substances?
Which of these have blood, lungs, kidneys or digestive system?
How are organ systems specialised for exchanging
substances?
Which of these have blood, lungs, kidneys or digestive system?
As organisms get b…..er or more c……….. ,
it becomes harder to exchange substances
with their surroundings
Stretch; note down four of the main
“substances” that need to be exchanged
and what process each substance is
involved in
How are organ systems specialised for exchanging
substances?
Surfaces where gases or dissolved food
(solutes) are exchanged are often
specialised so exchange is maximised.
How are organ systems specialised for exchanging
substances?
• Villi line the small intestine.
Food in intestine
How does food get into the blood?
Food in intestine
When you first start eating
digested food diffuses
across villi wall into the
capillaries.
(high to low)
How does food get into the blood?
Food in intestine
When you first start eating
digested food diffuses
across villi wall into the
capillaries.
Concentration of food
molecules in the blood
increases
Which of these villi would be better for exchanging solutes?
Explain why would one be better?
Key features that make the villi great for exchanging solutes
•Big surface area
•Very thin layer of cells between blood and dissolved food
in intestine (NOT “very thin CELL WALLS)
•Lots of capillaries to pick up dissolved food
The breathing system
windpipe
Ribs
Rib muscles
Diaphragm
Right Lung
Left Lung
The breathing system takes air into and out
of the body so we can obtain oxygen and get
rid of waste carbon dioxide
trachea
ribcage
diaphragm
thorax
Inhalation
(When we breathe out we exhale)
Exhalation
(When we breathe out we exhale)
The Alveoli
The air we inhale makes its way into thousands of
tiny “air sacs” (alveoli) in the lungs.
The outside of the alveoli is covered with
capillaries (tiny blood vessels).
Air rushes down the t………., through the airways of the lungs
and ends up in the a…….…
How are the lungs adapted for gas exchange?
Each alveolus is surrounded by capillaries which pick
up the …………. in each lungful of air you breathe in.
The capillaries
also bring carbon
dioxide (CO2)
from ………..cell
in the body and
let the CO2 out
into your lungs so
you can breathe it
out.
Which design would be better for the alveoli to exchange
gases with the capillaries of the lungs
•Big surface area
•Very thin layer of cells
•Lots of capillaries
Suggest how the changes in the tadpole shown in the
drawings help it to survive as it grows larger.
You should not refer to movement in your answer.
To gain full marks you should refer to structure X.
How has the use of artificial aids to
breathing developed?
Iron Lung
Modern Ventillator
Draws air into the lung
Pushes air into the lung
http://www.youtube.com/watch?v=
kM30mAEz5bA
http://www.youtube.com/watc
h?v=V8VIw0fk4X0
The blood now carries this
oxygen to the cells of the body.
Right
Lung
Left
Lung
Blood
vessel
O2
O2
Blood
Body cells
Cells
Oxygen diffuses from the blood into the cells
Carbon dioxide diffuses into the blood from the cells
Blood
coming from
the lungs
High
concentration
Low
concentration
Body cell
Oxygen