Download The Respiratory System

The Respiratory System
Chapter 13
Organs of the Respiratory System
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Nose
Pharynx
Larynx
Trachea
Bronchi & their smaller branches
Lungs
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Alveoli: air sacs where the ONLY gas exchange of
the respiratory system to the blood takes place. All
other structures are only conducting passageways
which allow air to reach the lungs!
Functions of the Respiratory System
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Purify
Humidify
Warms air coming into the lungs
These functions allow air coming into the lungs
to have fewer irritants and to function
properly.
The NOSE
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The only external visible part of the respiratory system
During breathing air enters the nose by passing through
the external nares/nostrils
The interior of the nose consists of a nasal cavity divided
by a nasal septum
Olfactory receptors: located in the mucosa in the slitlike
superior part of the nasal cavity, just below the ethmoid
bone
The NOSE
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Respiratory Mucosa: composes the rest of the
mucous lining of the nasal cavity, rests on a
network of thin-walled veins that warm air as it
flows past
The other mucosa glands moisten air and trap
incoming bacteria and other foreign debris
Ciliated cells: in the nasal mucosa they create a
current that moves contaminated mucus
posteriorly towards the pharynx where it is
swallowed and digested by stomach juices.
The NOSE
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Conchae: consists of 3 mucosa covered
projections/lobes on the lateral walls of the
nasal cavity. Their function is to increase the
surface area of the mucosa exposed to air.
They also create movement of air in the
nasal cavity and trap and prevent particles to
be deflected from the mucus lined surfaces
and prevent them from reaching the lungs.
The NOSE
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Palate: separates the nasal cavity from the oral
cavity below it.
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Hard Palate: anterior portion of the palate which is
supported by bone
Soft Palate: posterior portion of the palate which is
completely unsupported.
Cleft palate: Genetic defect where the bones forming
the palate fail to form completely and fuse medially. It
results in breathing difficulty and problems with oral
cavity functions such as chewing and speaking.
The NOSE
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Paranasal sinuses: located in the frontal,
sphenoid, ethmoid and maxillary bones.
These sinuses lighten the skull and act as
resonance chambers for speech. They also
produce mucus that drains into the nasal
cavities. Blowing the nose creates a
suctioning affect which clears the sinuses.
Nasolacrimal ducts: drain tears from the eyes
and also empty into the nasal cavity.
Infections of the Nasal Cavity
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Rhinitis:
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Inflammation of the nasal mucus.
Excessive mucus produced will result in nasal congestion and
postnasal drip.
Because the nasal mucus is continuous through the respiratory
tract infection can spread
Sinusitis:
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Inflamed sinuses
Very difficult to treat and causes changes in the voice
When the sinuses are completely blocked with mucus or
infectious matter the air is absorbed and a sinus headache
occurs.
The THROAT
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Pharynx: muscular passageway about 5 inches
long and is most commonly called the throat. It
serves as a passageway for air and food.
Nasopharynx: the superior portion of pharynx,
first place for air to enter from the nasal cavity
before it descends down the …
Oropharynx: anterior portion. Food also passes
down this portion along with the air.
The THROAT
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Layngopharynx: area where food and air
travel. Food is directed posteriorly to enter
the esophagus and air will travel down the..
Larynx: inferior portion of Pharynx
Auditory tube: drains the middle ear and
opens up into the nasopharynx. Since the
two are connected an ear infection maybe
turn into a sore throat or vice versa
The THROAT
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Tonsils: clusters of lymphatic tissue found in the
pharynx.
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Pharyngeal tonsils: most commonly called adenoids
are located high in the nasopharynx. When they
become inflamed it causes the person to breathe only
through the mouth
Palatine tonsils: are in the oropharynx at the end of
the soft palate
Lingual tonsils: are found at the base of the tongue
The THROAT
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Larynx: voice box, routes air and food into the proper
chambers and plays a small role in speech. Located
inferiorly to the pharynx it is formed by 8 rigid hyaline
cartilages and spoon shaped flap of elastic cartilage.
Epiglottis: the flap of elastic cartilage. Protects the
superior opening of the larynx and when we are not
swallowing allows air into the lower respiratory passages.
When we are swallowing or drinking however the
epiglottis tips up and closes off the larynx and routes food
towards the esophagus. If food or water does enter it
results in a cough reflex.
The THROAT
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Thyroid cartilage: large mass of hyaline
cartilage, is shield shaped and protrudes
anteriorly and is referred to as the “Adams
Apple”
Vocal folds: part of the mucus membrane of
the larynx which vibrate with expelled air
allowing us to speak
Glottis: the slitlike passageway between the
vocal folds
The THROAT
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Trachea: windpipe. It is the only way air can enter the
lungs. Air enters from the larynx and travels down its
length to the level of the 5th thoracic vertebrae. It is lined
with ciliated mucosa which propels the mucous full of
dust particles and debris away from the lungs
The trachea is rigid and its walls are supported by a cshaped ring of hyaline cartilage. The open part of the
rings allows the esophagus to expand anteriorly when we
swallow a large piece of food. The solid portions of the
wall keep the trachea open in spite of pressure changes
which occur during breathing.
The THROAT
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Primary Bronchi: there is a right and left primary
bronchi which are formed by the division of the
trachea. Each bronchi runs obliquely until it
enters the lung on its side.
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Right pulmonary bronchi: is wider, shorter and
straighter than the left and is a common site for an
inhaled object to become lodged. By the time air
enters the bronchi it is warmed, cleansed and
humidified. The smaller divisions of bronchi within the
lungs are the direct routes to the air sacs
The LUNGS
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Paired large organs which occupy the entire
thoracic cavity except for the central area which
contains the heart.
Apex: narrow superior portion of each lung located just
beneath the clavicle
– Base: broad area of the lungs which rests on the
diaphragm
Each lung is divided into lobes the right has 3 and the
left has 2.
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The LUNGS
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Pulmonary/Visceral Pleura: viscera covering the surface
of each lung.
Parietal Pleura: covers the walls of the thoracic cavity
Pleural Membranes: produces a slippery serous
secretion that allows the lungs to glide easily over the
thorax wall during breathing and causes the two pleural
layers to cling together
Pleurisy: inflammation of the pleura caused by decreased
secretion of pleural fluid causing the surfaces to become
dry and rough causing friction and stabbing pain with
each breath. It may also be caused by an excess of
secretion of pleural fluid which puts pressure on the lungs
making it hard to breathe.
The LUNGS
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Bronchioles: the smallest branch of the
conduction pathway
Bronchial or respiratory tree: the network of
branching bronchi into smaller and smaller
branches until they become bronchioles. All
of the branches except for the bronchioles
have reinforcing cartilage in their walls.
The LUNGS
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Terminal Bronchioles: Lead into …
Respiratory Zone: includes the respiratory
bronchioles, alveolar ducts, alveolar sacs,
and alveoli. This is the ONLY site for gas
exchanges. The structures in the respiratory
zone eventually become …
Alveoli: small air sacs where gas exchange
takes place. Alveoli make up the bulk of the
lungs and the rest is mostly air space.
The LUNGS
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Respiratory Membrane: the air-blood barrier.
Made up of alveolar and capillary walls. Air
passes by on one side and blood flows past
on the other. The gas exchange occurs by
simple diffusion through the respiratory
membrane. Oxygen passes from the alveolar
air into the capillary blood and the carbon
dioxide leaving the blood to enter the gas
filled alveolus.
The LUNGS
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Alveolar Walls: composed of a single layer of
squamus epithelial cells which are very thin.
The external surface of the walls is covered
with a web of pulmonary capillaries.
Alveolar pores: Connect the air sacs and
provide an alternate rout for air to reach the
alveoli when their bronchioles are clogged.