Download Respiratory Anatomy

Respiratory Anatomy
May 5, 2010
Notes from Lab and Dissection
General Functions of the System
• Ventilation (breathing) – the entrance and exit of
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air into and out of the lungs
External respiration – the exchange of gases
(carbon dioxide and oxygen) between the air
and blood
Internal respiration – the exchange of gases
between the blood and tissue fluid
Transport – of gases to and from the lungs and
the tissues
Anatomy and the flow of air:
• The Nose / Nasal passages begin to cleanse the air with
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course hairs inside the nostrils and continue to do so
with cilia and mucus in the nasal cavities.
Air warmed by the blood vessels lying close to the
surface of the lining of the airways.
Air is moistened by the mucus epithelium that lines most
of the air passages.
Conversely, as air leaves the body it deposits its moisture
along the way. This can cause the nose to drip and is
what is responsible for you being able to see your
breathe on a cold day.
Nose and Nasal Cavity
• 2 Nostrils
• 2 Nasal cavities separated by a septum
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composed of bone and cartilage.
Conchae are bony ridges that project out
laterally trapping air and increasing surface area
for moistening and warming.
Lacrimal glands (tear) drain into the nasal cavity
which is why your nose runs when you cry.
Nasal cavity is separated from the oral cavity by
the hard and soft palate.
Pharynx
• Broken into three parts: nasopharynx,
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oropharynx, and laryngopharynx.
The tonsils form a protective ring around the
pharynx – this is lymphatic tissue that protects
against the invasion of inhaled pathogens.
It is the junction of air and food passage. The
esophagus remains closed by the epiglottis
unless a person is swallowing.
Larynx
• A cartilaginous structure
• Contains the Adam’s Apple
• Called the voice box because it contains the
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vocal cords.
The vocal cords are mucosal folds supported by
elastic ligaments, and the opening between
them is the glottis.
When air is expelled past the vocal cords
through the glottis the cords vibrate producing
sound. The greater the tension on the cords
and the narrower the glottis, the higher the
pitch.
Trachea
• Tube with c-rings of cartilage. The open part of
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the c is facing the esophagus – why do you think
this is?
Lined with pseudostratified ciliated columnar
epithelium. Cilia beat upward moving the
particles out of the system. Goblet cells produce
mucus to trap debris.
Smoking destroys the cilia causing soot from
smoking to get caught in the lungs.
Bronchial Tree
• Contains the same histology as the trachea.
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Divides trachea into right and left primary
bronchi.
Branches into a large number of secondary
bronchi that eventually lead to bronchioles –
rings of cartilage are no longer present.
During an asthma attack, the smooth muscle of
the bronchioles contracts, causing constriction
and wheezing.
Each bronchiole leads to an elongated space
enclosed by a bunch of air pockets called alveoli.
Lungs
• Paired, cone-shaped structures.
• The right lung has 3 lobes and the left, 2.
The lobes are divided further into lobules
which each have a bronchiole serving
many alveolar sacs.
• Diaphragm sits inferiorly to the lungs.
• Each lung is enclosed by a pleural sac
(serous membrane).
Alveoli
• Composed of simple squamous epithelium and is
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surrounded by capillaries which are also
composed of simple squamous. What major
function does the structure of simple squamous
allow?
Alveoli are covered in surfactant, a lipoprotein
that allows them not to collapse under the
pressure of water surface tension.