Transcript Respiratory System Unit 1: Anatomy and Physiology

Respiratory System
Unit 1: Anatomy and Physiology
Kevin Browne
Learning Outcomes
Introduction
• What is the respiratory system?
• What is it responsible for?
• How many breaths do we take on average
each day?
The role of the respiratory system
The respiratory system helps the body obtain oxygen for respiration and remove the waste
product carbon dioxide.
As we breathe, oxygen moves through the surface
of the lungs into the body. It is then absorbed by
the blood cells and transported around the body
via the blood vessels.
The respiratory system is adapted for efficient
exchange of gases between the lungs and the blood.
What do you already know
• You will have studied the respiratory system at
GCSE level or at Level 2
• Individually write down as many parts of the
respiratory system as you can
• Pair up
• Share with the group
The respiratory system
The passage of air from nose/mouth to lungs
Click the
mouse to
follow the
passage of
air from the
nose/mouth
to the lungs
Nose
Air enters the
respiratory
system
through the
nose and
mouth. It is
here that the
air is warmed,
filtered (by tiny
hairs), and
moistened.
From the nose,
the air passes
through the
throat (the
pharynx).
Pharynx
The pharynx
lies behind
the nose and
mouth and
both cavities
open into it.
Both food
and air pass
through the
pharynx, the
food is then
directed to
the
oesophagus.
Larynx (Voice box)
The cavity of
the larynx is
separated
from the
pharynx by a
flap known as
the epiglottis.
This prevents
food from
entering the
windpipe
(trachea), into
the lungs.
Trachea (Windpipe)
The trachea is
approximately
10-12cm long
and is kept
open by a
series of rings
of cartilage. It
contains cells
which remove
foreign
particles from
the air.
Bronchi
The trachea
divides into
two bronchi,
one leading to
each lung.
Each bronchi
then breaks
up into
smaller tubes
known as
bronchioles.
Bronchioles
The bronchial
tubes further
divide into
smaller tubes
called
bronchioles
before
terminating in
clusters of air
sacs known as
alveoli.
Alveoli
Alveoli look like
bunches of grapes.
There are millions
of alveoli in each
lung and it is here
that gaseous
exchange takes
place. They have
large surface
areas, thin walls
and are
surrounded by a
network of
pulmonary
capillaries.
Ventilation
• Click here to see an animation of breathing
• Ventilation
Mechanisms of breathing –
inspiration
When you breathe in:
Intercostal muscles
pull ribs up and out
the intercostal muscles between the ribs
contract, pulling the chest walls up and out.
the diaphragm muscle
below the lungs contracts and flattens,
increasing the size of the chest.
the lungs increase in size, so the pressure
inside them falls. This causes air to rush in
through the nose or mouth.
Diaphragm
contracts and
moves down
Mechanisms of breathing – inspiration
During Exercise (Inhalation)
• During exercise the diaphragm and the
intercostal muscles contract which makes the
ribs moves upwards and outwards and results
in more air being taken in
Mechanisms of breathing – expiration
When you breathe out:
Ribs move in
and down
the intercostal muscles between
the ribs relax so that the chest walls
move in and down.
the diaphragm muscle below the
lungs relaxes and bulges up,
reducing the size of the chest.
the lungs decrease in size, so the
pressure inside increases and air is
pushed up the trachea and out
through the nose or mouth.
Diaphragm
relaxes and
bulges up
Mechanisms of breathing – expiration
During exercise (Exhalation)
• During exercise the intercostal muscles
contract to help decrease the size of the
thoracic cavity, which means that more air can
be forced out.
Gas exchange at the alveoli
The alveoli are bunches of tiny air
sacks inside the lungs.
Each individual sack is called an
alveolus.
When you breathe in, they fill with
air.
The alveoli are covered in tiny capillaries (blood vessels).
Gases can pass through the thin walls of each alveolus and capillary, and into the
bloodstream.
Gases can also pass from the bloodstream into the alveolus.
Gas exchange at the alveoli: describe in
your own words what is happening
Gaseous exchange
• Oxygen passes into the body and carbon dioxide leaves the
body through the process called gaseous exchange.
• For this process to work we must control the amount of
each gas on each side of a semi-permeable membrane (a
wall one cell thick that lets some things through but not
others).
• A gas will always move from an area of high concentration
(or pressure) to an area of low concentration (or pressure).
• When we breathe in there will be a high concentration of
oxygen in the lungs and a low concentration in the blood.
Therefore the oxygen will pass from the lungs into the
blood capillaries surrounding the alveoli.
Continued
• This highly oxygenated blood now transports
the oxygen to the muscle capillaries, which
have a low concentration of oxygen, thus
allowing the oxygen to pass into the muscle
where it will be used to release energy.
• Carbon dioxide is diffused from the muscles
into the bloodstream where it is transported
to the lungs and diffused out into the alveoli.
The answers
• 1 .Air containing oxygen is inhaled and taken to the ...
• 2 .alveoli in the lungs, where the oxygen diffuses into the
...
• 3 . blood and is taken to the heart to be pumped around
the ...
• 4 . body to the muscles. At the same time ...
• 5 .carbon dioxide produced by the muscles is taken to the
..
• 6 .heart to be pumped to the ...
• 7 .lungs, where it diffuses out of the blood and into the ...
• 8 . alveoli to be exhaled.
Summary