Download Gas Exchange BASIC overview

Gas Exchange
Gas exchange SLOs
 Be
able to define gas exchange
 Be able to label and list the parts of
the human breathing system
 Be able to explain the breathing
process
Respiration
Release of energy
in the cells of the
body (needs
OXYGEN)

Breathing
(ventilation)
Mechanical
movement of
body parts in
order to inhale
and exhale air
Inhale- exhale
Ribs move
up and out
Diaphragm
moves down
Ribs move
down and in
Diaphragm
moves up
From the front…
Lung capacity demo/practical
Did you know…?
The human lung can hold 6 litres of air.
But only a small amount of air is moved
in and out of the lungs during breathing.
(500ml in normal breathing, 4.6 litres
after inhaling forcefully, then breathing
out completely)
The largest human lung capacity recorded is
that of British rower Peter Reed (rower) at 11.68
litres. roughly twice that of an average person
Lung capacity depends on:
 Gender
 Height
 Smoking
 Exercise
Pneumothorax
: air trapped in
the chest
cavity.
(Tension pneumothorax: lifethreatening)
Gas exchange
Gas
Oxygen
Carbon
dioxide
Nitrogen
Inhaled air
(air entering
lungs)
21%
Exhaled air
(air leaving
lungs)
17%
0.04%
4%
78%
78%
The air we breath out have less
oxygen and more carbon dioxide
It is important to distinguish between
3 important terms:
Gas Exchange = oxygen enters the body &
carbon dioxide leaves.
 Breathing = a mechanical process that moves
air in & out of the lungs.
 Respiration is a biological process occurring in
all cells in the body where food & oxygen are
taken in to release energy for the cell.

Be careful not to use the word respiration when
you mean breathing or gas exchange.
Label diagram of human resp. sys.
Alveoli (plural)
Alveolus (single)
Inflated
Surfactant
Lipoprotein
produced by
alveolar cells
 Reduced surface
tension (if no
surfactant – lung
cannot inflate
normally)

Gas exchange
WB page 12 - Read notes and create a flow
diagram following the movement of air
from the atmosphere to the bloodstream
AIR
(outside)
Oral
cavity
AIR
(outside)
Bronchiole
Alveoli (air
sacks)
Oral
cavity
Bronchi
Surfactant
Bloodstream
Larynx
(voice box)
Trachea
(air pipe)
Capillary
wall
In the alveoli:
- oxygen moves into the
blood
- carbon dioxide moves
out of the blood
WB page 13:
Deoxygenated blood:
blood with little
oxygen
Oxygenated blood: blood
with lots of oxgyen
Nose
Air enters and leaves through – filters
air for dust/bacteria using hairs & mucus
Voice box – may be used to make
larynx
sounds
Connects the mouth and lungs, rings of
Trachea cartilage keep it open for efficient gas
exchange
Where the trachea splits into two tubes
Bronchi
and enters the lungs
Thin walled ‘bunches of balloons’ have
alveoli a rich blood supply for easy gas
exchange
6. Inhale – breathing in – muscles
between the ribs contract pulling the
ribs up and out. The diaphragm
moves down and flattens out and
this increases the volume of the chest
Exhaling – Breathing out –
diaphragm relaxes and moves up, and
ribs move down and in.
http://health.howstuffworks.com/adam200020.htm