BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
UNIT 5
THE BODY IN ACTION
The respiratory system
Dale Embleton
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The respiratory system
What you need to learn …
• The structure of the respiratory system
• The functions of the respiratory system
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The respiratory system
Respiratory system
•The mechanism of respiration is the
process by which living cells of the body
receive a constant supply of oxygen, and
remove carbon dioxide.
•All cells require oxygen to function
•Also plays a role in regulating the body’s
acid-base balance
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
STRUCTURE
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The respiratory system STRUCTURE
Respiratory system consists of
• Nose
• Naso-pharynx
Task
• Pharynx
Use resources and
• Larynx
labels on whiteboard
• Trachea
• Bronchi
• Lungs
– bronchioles
– alveoli
Complete Worksheet
to label the respiratory
system
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The Respiratory System STRUCTURE
• Air is drawn through the _____________
and sometimes the _________________
and passes through the respiratory tract to
reach the _____________.
• The RT can be subdivided into the Upper
and Lower Respiratory Tracts.
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
Respiratory Tracts STRUCTURE
TASK
•
Read through your handout on the upper
and lower respiratory tracts.
•
Describe each with 3-4 key points
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The Lungs STRUCTURE
An A4 Task
• Your A4 handout has some information on
the lungs
• Use this information to draw and label a
very simple diagram of the lungs.
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
FUNCTIONS
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The Mechanics of Breathing. FUNCTIONS
• Breathing is the process by which air is
transported into and out of the lungs.
• Two distinct phases
• It is regulated by the respiratory centres in
the brain and stretch receptors in the air
passage and lungs.
• The thorax increases in size to let air in
and decreases to force air out.
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The Mechanics of Breathing. FUNCTIONS
Two distinct phases are:
• Inspiration
– Intercostal muscles contract to lift ribs upwards and
outwards
– Diaphragm is forced downwards
– Sternum is forced outwards
– This expansion leads to a drop in pressure (below
atmospheric pressure), so air floods into the lungs.
– O2 exchanged for CO2.
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The Mechanics of Breathing. FUNCTIONS
Two distinct phases are:
• Expiration
– Intercostal muscles relax so that the ribs and
sternum collapse
– Diaphragm extends upwards
– Pressure is increased and air is expelled.
• During exercise there is an increased
demand for oxygen. Therefore, there is
greater work for the muscles and diaphragm
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
Gaseous exchange: FUNCTIONS
Gaseous exchange in the alveoli …
Oxygen in:
• Oxygen breathed in, enters lungs into
alveoli
• Passes through alveoli walls into
capillaries
• Blood carries oxygen to body cells
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
Gaseous exchange: FUNCTIONS
Gaseous exchange in the alveoli …
Carbon dioxide out:
• Blood carries waste carbon dioxide from body
cells to alveoli along capillaries
• Carbon dioxide passes through capillary walls
into alveoli
• Carbon dioxide travels out of lungs up windpipe
Task: Complete diagram of Gaseous exchange in
the alveoli.
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
Gaseous exchange: FUNCTIONS
Capillary from
pulmonary artery
Red cell
Oxygen
enters red
cells
Film of
moisture
Di
ffu
sio
n
of
ca
d io
rb
x id
on
e
Epithelium
of alveolus
To pulmonary vein
Carbon dioxide
escapes into
alveolus
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
Gaseous exchange: FUNCTIONS
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
Respiratory Rates and Lung Volumes: FUNCTIONS
How much air you breathe
• Tidal volume – volume of air breathed in
with each breath
• Respiratory rate – number of breaths
taken per minute
• Minute volume – volume of air breathed
per minute
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
Respiratory Rates and Lung Volumes: FUNCTIONS
Key point
• Minute volume = Tidal volume X
Respiratory rate
• Task: Complete Worksheet 53 (2,3,4) and
Worksheet 54 (1)
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
VT tidal volume during
normal, quiet breathing
ERV expiratory reserve
volume
FRC functional residual
capacity
EVC expiratory vital capacity
IVC inspiratory vital capacity
TLC total lung capacity
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
Respiratory Rates and Lung Volumes: FUNCTIONS
How big are the lungs?
• Vital capacity = maximum amount of air
you can breathe out, after breathing in as
deeply as you can (usually 4.5–5 litres)
• Residual volume = amount of air left in
lungs after you breathe out as hard as you
can (usually 1–1.5 litres)
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The respiratory system
Composition of air entering the lungs
• 21% oxygen
• 79% nitrogen
• Small amount carbon dioxide
• A little water vapour
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The respiratory system
Composition of air leaving the lungs
• 17% oxygen
• 79% nitrogen
• 3% carbon dioxide
• A lot of water vapour
BTEC NATIONAL Sport
UNIT 5 THE BODY IN ACTION
The respiratory system
What you need to learn …
• The structure of the respiratory system
• The functions of the respiratory system