Download respiratory system

Today I’m going to stick to basic anatomy of the resp system or else I could go
on all day about the muscular, skeletal and circulatory system that are all
involved in the chest
So I’m hoping most of this is common sense for all of us by now but if not, lets
take a trip down memory lane.
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The thorax consists of The Superior Thoracic Aperture which is a small open
aperture at the superior portion of the thorax and the
Inferior Thoracic Aperture which is a large closed aperture at the inferior
portion of the thorax that is sealed by the diaphragm
It also contains The right and left pleural cavities that surround each lung. The
pleural cavities are completely separated from each other by the mediastinum
and the mediastinum that contains the heart, esophagus, trachea, major
nerves and major systemic blood vessels
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Thoracic wall consists of the skeletal elements and muscle that house the
thorax
Posteriorly - 12 thoracic vertebrae
Anteriorly - the sternum
Laterally – 12 ribs on each side and 3 layers of flat muscles
Each lung has an Apex (that projects above rib 1 and into the root of the neck)
and a base (that sits on the diaphragm)
The Right lung consists of 3 lobes, inf lobe, middle lobe of the right lung and
sup lobe these are separated by 2 fissures oblique fissure and horizontal
fissure
The left lung only has 2 lobes, the Sup and Inf lobes which are seperated by
the obl fissure
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Looking laterally we can see that most of the lower lobes of both lungs sit
posteriorly
The trachea extends from the larynx at the level of C6 to T4-T5 where it then
divides from the carnia into the right and left primary bronchi.
The right is known to wider and shorter than the left and therefore foregin
objects are more likely to become stuck in the right bronchus. The right
primary bonchus divides into 3 secondary bronchus and because of that it has
3 lobes
The left is almost twice as long as the right but only divides into 2 secondary
bonchrus and that is why the left lung only has 2 lobes.
From there each secondary bronchi subdivide into small terminal bronchioles
and then into small air sacs called alveoli.
The right and left pulmonary arteries originate from the pulmonary trunk and
they carry deoxygenated blood to the lungs from the right ventricle of the heart
On each side there is a sup and inf pulmonary vein that carries oxygenated
blood from the lungs back to the heart
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The resp system is made up of airways, lungs and respiratory muscles
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Oxygen enters the respiratory system through the mouth and the nose. The
oxygen then passes through the larynx and the trachea, on its way to the lungs
for the exchange of gases
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Most of the respiratory tract exists merely as a piping system for air to travel in
the lungs, and alveoli are the only part of the lung that exchanges oxygen and
carbon dioxide with the blood.
In the chest cavity, the trachea splits into two smaller tubes called the bronchi.
Each bronchus then divides again forming the bronchial tubes. The bronchial
tubes lead directly into the lungs where they divide into many smaller tubes
which connect to tiny sacs called alveoli. The inhaled oxygen passes into the
alveoli and then diffuses through the capillaries into the arterial blood.
Meanwhile, the waste-rich blood from the veins releases its carbon dioxide into
the alveoli. The carbon dioxide follows the same path out of the lungs when
you exhale.
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The diaphragm's job is to help pump the carbon dioxide out of the lungs and
pull the oxygen into the lungs. When the diaphragm contracts, oxygen is pulled
into the lungs. When the diaphragm relaxes, carbon dioxide is pumped out of
the lungs.
There are numerous muscle that help with breathing including the external
intercostal which moves ribs superiorly and the internal intercostal which move
the ribs inferiorly and the innermost intercostal that acts with the internal
intercostal muscles
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Everyone sit back, relax, close your eyes and take a breath in… and out.
You have now just contracted your diaphragm to inhaled oxygen and exhale
carbon dioxide
On average you will subconsciously do this 20 000 times a day!
So lets so the average age in here is 35 you will have breathed over 2
thousand 5 hundred million times in your life, don’t take it for granted
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