Transcript The Cardio-vascular System

BTEC Level 3 - Sports
Development, Coaching and Fitness
Unit 1 : Anatomy
Learning Outcomes
• Describe (and explain) the pleural membranes
• Describe the mechanism of breathing
• Describe (and explain) the control of breathing
• Describe (and explain) the functions of the
respiratory system
• Define lung volumes
Where are these and what do they do…?
Diaphragm
Nasal Cavity
Bronchus
Larynx
Epiglottis
Pharynx
Alveoli
Mouth
Pleura
Bronchi
Bronchioles
Lungs
Trachea
The
Respiratory
System
Pleural Membranes
• Visceral Pleura – inner
pleural membrane which
attaches to the lung
• Parietal Pleura – outer
pleural membrane which
attaches to the thoracic
wall
• Pleural cavity – space
between the pleura layers
• Pleural fluid – found in
the pleural cavity
Mechanisms of Breathing
• Air needs to flow in and out
of the respiratory system
• ‘Ventilation’ - is all to do
with pressure changes
within the thorax (chest
cavity)
Breathing – Muscles
The key muscles involved:
1. Diaphragm
2. Intercostal muscles:
• External intercostal
muscles
• Internal intercostal muscles
Breathing – Muscles
• Diaphragm – a large muscle which draws air into
the lungs
• External intercostal muscles – these contract
to draw air into the lungs (they pull the ribs up
and out)
• Internal intercostal muscles – these force air
out of the lungs (they pull the ribs down and in)
– used during exercise but not normal breathing
Breathing
Ventilation – mechanism of breathing in and out
Breathing in ‘inhalation’
Breathing out ‘exhalation’
Inhalation
• Diaphragm contracts
• External intercostal
muscles contract
• Ribs move out and up
• Thoracic cavity size
increases
• Thoracic pressure
decreases
• Air rushes into the
lungs - inhalation
Exhalation
• Diaphragm relaxes
• External intercostal
muscles relax
• Ribs move in and down
• Thoracic cavity size
decreases
• Thoracic pressure
increases
• Air is pushed out of
the lungs - exhalation
Breathing Control
Under normal resting conditions…
• Breathing is controlled by the central nervous
system (neural control)
• Neural control – the central nervous system
(brain and nerves)
• You will naturally breath about 12 times a
minute – your brain makes this happen!
Breathing Control
Under exercise / stress…
• Chemical control starts to come into control
• Increased CO2 and/or low O2 levels are
detected by receptors and then the CNS
increases its activity = breathing speeds up!
Functions of the Respiratory System
1. Protection
• Identify three important structural aspects
• Explain how they protect
• Write a paragraph…
Functions of the Respiratory System
2. Warm and moisten air
• How does this happen?
• Why is it important?
• Write a paragraph…
Functions of the Respiratory System
3. Gas exchange
• What is this?
• How does this happen?
• Why is it important?
• Write a paragraph…
Gas Exchange
‘Gas exchange’ – gases swap
place
Get O2 into the body / Remove
CO2
This occurs between the air
inside the alveoli of the lungs
and the blood in the capillaries
which surround the alveoli
Gas Exchange
• The lungs are the size of
a tennis court?!
• Why such a large surface
area?
• Capillaries cover the
alveoli
• Gas exchange
• Draw a diagram
Gas Exchange
• ‘Diffusion’ – transport of a substance from a
high pressure to a lower pressure (across a
semi-permeable membrane)
• Oxygen diffuses from the lungs (alveoli) into
the CV system (capillaries)
• Carbon dioxide diffuses from the CV system
into the lungs
• Explain this process
What do these phrases mean?
Tidal Volume
Inspiratory Reserve Volume
Vital Capacity
Expiratory Reserve Volume
Residual Capacity
Total Lung Capacity
Respiratory Volumes
Total Lung Volume (Litres)
7
D
6
5
B
A
4
3
2
C
1
E
0
Time
F
Respiratory Volumes
• Plot a graph using the data below
• Label TV, IRV, EVR, RV, VC & TLC
Time
point
Lung
volume
(Litres)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
3.0 3.5 3.0 3.5 3.0 6.0 3.0 3.5 3.0 3.5 1.5 3.5 3.0 3.5 3.0 3.5
Respiratory Volumes
Total Lung Volume (Litres)
7
D:VC
6
5
B:IRV
A:TV
4
3
2
1
C:ERV
E:RV
0
Time
F:TLC
Pulmonary Ventilation
Pulmonary Ventilation (VE) – the amount of air
we breathe in and out in 1 minute
VE = number of breaths x tidal volume
Average tidal volume at rest = 0.5L
Task - Estimate your pulmonary ventilation!
What methods can we use to
assess lung function?
Why assess
lung function?
Measuring Lung function
Spirometry – can measure different lung
volumes
Peak flow meter – measures the maximum rate
of air flow during forced expiration
Pulse oximetry – measures O2 saturation levels
Peak flow
Normal
Values for
adults
What methods can we use to
assess lung function?
Why assess
lung function?
Why assess lung function?
• How much air your lungs can hold
• How quickly you can move air in and out of the
lungs
• How well you can perform gas exchange
• Why?
Asthma
Task… discuss with your partner the following:
1. What areas of the lung does asthma affect?
2. What are the symptoms of asthma?
3. What happens during asthma ‘the pathology’?
4. What causes asthma?
Asthma
Task…
Which respiratory volumes would be affected by
asthma…?
Fully explain the impact of asthma (M3)
COPD
‘Chronic Obstructive Pulmonary Disease’
e.g. emphysema
e.g. bronchitis
Task… Explain the impact of COPD
COPD
Emphysema
Bronchitis
Asthma