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Ventilation
Noadswood Science, 2012
Wednesday, May 24, 2017
Ventilation

To know how ventilation takes place in the body
Exercise

Make a list of all the things which occur to your body when you
exercise – next to these write a short description explaining
these changes and why they occur…
Exercise

When you exercise your body tries to maintain a constant
internal environment – in order to do this is needs to regulate
many processes

As soon as exercise begins you’ll notice more frequent muscle
contraction, raised body temperature and pulse, and deeper
breathing (tidal volume)

Longer-term effects occur as the body adapts to regular
exercise, including your heart getting larger, bones becoming
denser and the vital capacity of your breath deepening
Cardiovascular System

Immediate effects: – Increased heart rate and stoke volume (more powerful
contraction allowing for greater pump volume)
– Blood diverted to muscles from digestive system
– Blood temperature rise
– Blood vessels near skin allow for heat loss

Regular training effects: – Heart muscle increases in size and strength and
cardiac output increases (blood pumped)
– Lower resting heart rate and quicker recovery
– Reduced risk of heart disease
– Increased blood volume and red blood cells
– Increased number of capillaries in muscle
Respiratory System

Immediate effects: – Increased rate of breathing
– Increase in tidal volume (amount of air breathed in)

Regular training effects: – Strength of diaphragm and intercostal muscles
– Increased number of alveoli
– Increase in vital capacity (amount of air that can
be forcibly exhaled after breathing
– Increase in O2 delivery and CO2 removal
Respiratory System

What does the respiratory system do? What parts does it
consist of?

The respiratory system contains the organs that allow us to
get the oxygen we need and to remove the waste carbon
dioxide

It consists of: –
Lungs (in upper part of body (thorax))
– Tubes leading from the lungs to the mouth and nose
– Various structures in the chest that allow air to move
in and out of the lungs
Respiratory System

Movements of the ribs, rib muscles and diaphragm allow air into and
out of the lungs: this is called breathing or ventilation – when we
breathe in, we inhale and when we breathe out, we exhale

Air passes between the lungs and the
outside of the body through the
trachea

The trachea divides into two bronchi,
with one bronchus for each lung

Each bronchus divides further in the
lungs into smaller tubes called
bronchioles

At the end of each bronchiole, there is
a group of tiny air sacs called alveoli
Breathing / Ventilation
Breathing in (inhale) - ribs move up and out, diaphragm contracts (pulled down)
Breathing out (exhale) - ribs move down and in, diaphragm relaxes (moves upward)
Breathing

Complete the breathing
worksheet - stick this in your
book (plus all other work)
Breathing
Gas Exchange

For respiration to occur, we need to get oxygen from the air to
the blood, and remove waste carbon dioxide from the blood

Alveoli in the lungs are adapted to make gas exchange happen
easily and efficiently: they cause the lungs to have a very large
surface area; are moist with thin walls; and have many
capillaries
The gases move via diffusion (net [high] to [low])
Summary

The breathing system allows for gas exchange - it needs to be
as efficient as possible (alveoli have thin walls and very large
surface areas (about the same area as a tennis court if laid
flat)!
Summary

Oxygen is transferred into the blood, and carbon dioxide out of
it via diffusion (net movement from high concentration to low
concentration)…
Lung Dissection

Observe the lung dissection and try and identify the key areas
and how they allow for gaseous exchange…