The repiratory system and gas exchange in humans

ppt. that follows Edexel igcse Biology- has structure of lungs, breathing, effect of exercise of breathing, alveoli and how they have adapted to their role, gas exchange, and the effects of smoking on the lungs. Hope you find it useful :)

HideShow resource information

Slides in this set

Slide 1

Preview of page 1

The respiratory system and gas
exchange in humans
follows syllabus for Edexel igcse Biology…read more

Slide 2

Preview of page 2

This is the Thorax
the thorax is the top part
of your body. It is
separated from the bottom
by the diaphragm.…read more

Slide 3

Preview of page 3

The lungs are like large
sponges, protected by the
ribs and surrounded by
the pleural membrane.
The air you breathe goes in
through the Trachea
The Trachea then splits
into two smaller tubes
called Bronchi, one going
into each lung.…read more

Slide 4

Preview of page 4

The Bronchi split into
progressively smaller tubes
called Bronchioles.
The Bronchioles end in small
bags called Alveoli, which is
where gas exchange takes
place.…read more

Slide 5

Preview of page 5

The lungs contain millions of alveoli.
The blood passing around the alveoli has
just returned to the lungs, so it is full of
carbon dioxide.
The oxygen in the alveoli is a high
concentration, so it diffuses out through
the wall of the sac into the blood, which
has a low concentration.
The Carbon dioxide in the blood diffuses
into the alveolus to be breathed out.…read more

Slide 6

Preview of page 6

The alveoli are suited to this job
because they are only one cell thick,
which means that there is less distance
to diffuse through.
Because there are so many alveoli,
there is a large surface area for gas
The alveoli are permeable, which
means gases can pass through them
They have a good blood supply, to
maintain a high concentration
gradient.…read more

Slide 7

Preview of page 7
Preview of page 7

Slide 8

Preview of page 8
Preview of page 8

Slide 9

Preview of page 9
Preview of page 9

Slide 10

Preview of page 10
Preview of page 10


No comments have yet been made

Similar Biology resources:

See all Biology resources »