Transcript Respiratory System

Respiratory System
Allied Health Sciences I
Upper
Respiratory
Tract
Nasal Cavity
The anterior nares are our nostrils where air enters into
our bodies. Our nasal cavity is divided into the R and L
chamber, or smaller cavity. The nasal septum divides
these R and L chambers. These cavities are lined with
mucous membranes.
 Cilia or small hairs entrap and prevent the passage of
larger dirt particles.
 The olfactory nerves are located in the mucous
membrane in the upper part of the nasal cavity. These
nerves endings are responsible for our sense of smell.
 Mucous membrane line the sinuses and they help to
warm and moisten air that passes through them. The
sinuses also give resonance to the voice.
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Pharynx
This is known as your throat. The air enters this area
after leaving the nasal cavity. The throat serves as a
passageway for air and food.
 The pharynx is divided into three sections.
1. The upper pharynx also called the nasopharynx.
2. The middle section is called the propharynx and is
located just behind the mouth.
3. The lowest area is called the laryngopharynx. This is
where air passes through the lungs and food passes
through to go to the stomach.
 The epiglottis acts as the “lid” to cover the opening into
the larynx when food is swallowed.
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Larynx
This is known as the voice box and is triangular
chamber found below the pharynx.
 It is made of fibro-cartilaginous plates and the
largest of these is called the Adams Apple.
 The vocal cords are located in the larynx. The
glottis is a space b/w the vocal cords.
 When air is expelled from the lungs, it passes the
vocal cords. This sets off a vibration, creating
sound. The action of the lips and tongue on this
sound produces speech.
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Trachea
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The trachea is also known as the wind pipe.
The trachea is in front of the esophagus and continues
and forms the two bronchi (one for each lung).
The walls of the trachea are composed of alternate bands
of membranes, and fifteen to twenty C- shaped rings of
hyaline cartilage. This cartilage allows the trachea
not to collapse.
The trachea can be obstructed by large pieces of food,
tumorous growths, or the swelling of inflamed lymph
nodes in the neck.
The trachea is lined with mucous membrane and cilia.
The cilia helps to sweep any entrapped dust particles
from pharynx.
Lower
Respiratory
Tract
Bronchi and Bronchioles
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The lower end of the trachea divides in two into
the R bronchus and L bronchus.
The R bronchus is shorter, wider and more vertical in
position. These bronchi enter each lung and further
divides into bronchial tubes and then to smaller
bronchioles. The bronchi have cilia just like the
trachea.
The bronchial tubes and smaller bronchi are
ringed with cartilaginous plates.
 At the end of each bronchiole, there is an
alveolar duct which ends in a sac-like cluster
called alveolar sacs (alveoli).
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Alveoli
The alveoli sacs have many alveoli and are
composed of single layer of epithelial tissue.
 There are about 500 million alveoli in the adult
lung.
 Their inner surfaces are covered with a lipid
material known as surfactant. This material
helps stabilize the alveoli, preventing them from
collapsing.
 Each alveolus is encased by a network of
capillaries. The rapid exchange of 02 and C02
occurs through moist walls of the alveoli and
capillaries.
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Lungs
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Two fairly large cone shaped organs that fill the two lateral
chambers of the thoracic cavity. They are separated from each
other by the mediastinum also called the interpleural space
and is situated b/w the lungs along the median plane of the
thorax.
The upper part of the lung is underneath the collarbone is the
apex and the broad lower part is the base. Each base is
concave and this shape allows it to fit snuggly next to the
convex part of the diaphragm.
Because the lungs have so much air in them, they are very
porous and spongy.
The R lung is larger and broader than the L lung because the
heart is positioned toward the left side.
The R lung is divided by fissures (clefts) into three lobes:
superior, middle, and inferior. The L lung is smaller and is
subdivided into two lobes: superior and inferior.
The lungs are covered with a thin, moist slippery membrane
made up of tough endothelial cells or pleura.
Functions of the Respiratory
System
 Provides
the structures of the exchange of
02 and C02 in the body through
respiration.
 Responsible for the production of sound,
the larynx contains the vocal cords. When
air is expelled from the lungs it passes over
the vocal cords and produces sound.
Subdivisions of the Respiratory
System
External Respiration- the exchange of 02 and C02
b/w the lungs, the body, and the outside environment.
 Internal Respiration- the exchange of C02 and 02
b/w the cells and the lymph surrounding them, plus the
oxidative process of energy in the cells.
 Cellular Respiration- involves the use of oxygen to
release energy stored in the nutrient molecules. Much of
the energy that is released is in the form of heat to
maintain body temperature.
 Control of Breathing- controlled by neural (nervous)
and chemical factors. ***
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Subdivisions of the Respiratory
System cont…
Neural Factors- the respiratory center is
located in the medulla oblongata in the brain.
 An increase of C02 or lack of 02 in the
blood will trigger the respiratory center.
 There are two neuronal or nerve pathways that
are involved in breathing.
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There are motor nerves and one group called the
phrenic nerves leads t0 the diaphragm and the
intercostals muscles.
The other nerve pathway carries sensory impulses
from the nose, larynx, lungs, skin, and abdominal
organs via the vagus nerve in the medulla.
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The HeringBrewer reflex is a lung reflex that
prevents the lungs from overstretching.
Chemical Factors
 ***Chemical
control of respiration is
dependent upon the level of carbon
dioxide in the blood. As the C02 rich blood
circulates through the respiratory center it
senses the increased C02 in the blood and
increases the respiratory rate.***
Lung Capacity and Volume
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A spirometer is a device used to measure how much air
you can hold which would be your lung capacity.
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Tidal Volume is the amount of air that moves in and out of the lungs
with each breath. Normal amount is about 500 ml.
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Inspiratory Reserve Volume (IRV) is the amount of air you can force a
person to exhale over and above the tidal volume. The normal amount is
1000ml.
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Vital Lung capacity is the total amount of air involved with tidal
volume, inspiratory reserve volume, and expiratory reserve volume.
Normal vital capacity is 4500ml.
Residual volume is the amount of air that cannot be voluntarily
expelled in the lungs. It allows for the continuous exchange of gases
b/w breaths. The normal residual amount volume is 1500ml.
Functional Residual Capacity is the sum of the expiratory reserve
volume plus the residual volume. The normal amount is 2500ml.
Total lung capacity includes tidal volume, inspiratory reserve,
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expiratory reserve, and residual air. The normal amount
is 6000ml.
Types of Respiration
Apnea is the temporary stoppage of breathing
movements.
 Dyspnea is difficult, labored or painful breathing, usually
accompanied by discomfort and breathlessness.
 Eupnea is normal or easy breathing with the usual quiet
inhalations and exhalations.
 Hyperpnea is an increase in the depth and rate of
breathing accompanied by abnormal exaggeration of
respiratory movements.
 Orthopnea is difficult or labored breathing when the
body is in a horizontal position. It is usually corrected
upon taking a sitting or standing position.
 Tachypnea is an abnormally rapid and shallow rate of
breathing.
 Hyperventilation can be caused by disease or stress.
Rapid breathing occurs which causes the body to lose
carbon dioxide too quickly.
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Disorders of the
Respiratory
System
Infectious Causes
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The common cold causes the greatest loss in production each year. This
respiratory infection spreads quickly through the classroom, factory, or
business office.
Pharyngitis is more commonly known as the sore throat.
Laryngitis is an inflammation of the voice box. Laryngitis can be
recognized by the incidence of hoarseness or loss of voice.
Sinusitis is an infection of the mucous membrane that lines the sinus
cavities.
Bronchitis is an inflammation of the mucous membrane of the trachea
and the bronchial tunes which produces excessive mucous.
 Chronic Bronchitis usually occurs in muddle or old age. Cigarette smoking
is the most common cause of chronic bronchitis.
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Influenza or more commonly known as the “flu” is a viral infection
characterized by inflammation of the mucous membrane of the
respiratory system.
Pneumonia is caused by a bacteria or virus and is an infection of the
lung or lungs.
Infectious Causes cont…
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Tuberculosis is an infectious disease of the lungs.
Systems of TB are cough, low grade fever in the
afternoon, weight loss, and night sweats.
Diphtheria is caused by the Corynebacterium
diphtheria and is very infectious. Children receive
an immunization for this.
 Pertussis (whooping cough) is characterized by
severe coughing episodes that end in a “whooping”
sound and dyspnea. Children also receive an
immunization for this.
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Noninfectious Causes
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These are respiratory problems that aren’t infectious or are unrelated to
an infectious cause.
Rhinitis is the inflammation of the nasal mucous membrane causing
swelling and increased secretions. More commonly know as “hay fever”.
Asthma is an inflammatory response which causes the airway to be
obstructed.
 Symptoms include difficulty exhaling, dyspnea, wheezing (sound produced
by a rush of air through a narrowed passageway), and tightness in the chest.
 Treatment= anti-inflammatory drug
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Atelectasis results when there is bronchial occlusion which causes the
lungs to fail normal expansion.
Bronchiectasis is an inflammation accompanied by heavy pus secretion
that causes dilation of a bronchus.
Silicosis is when the lungs become fibrosed which results in a reduced
capacity for expansion.
Nasal polyps are growths that occur sometimes in the sinus cavity and
caused an obstruction of the air pathway.
Noninfectious Causes cont…
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Chronic Obstruction Pulmonary (COPD) indicates chronic lung
conditions, especially emphysema and chronic bronchitis.
Emphysema- the alveoli of the lung become over dilated, lose their
elasticity and cannot rebound. The alveoli may eventually rupture. Air
becomes trapped and it is very difficult to exhale. The patient with
emphysema becomes very dyspneic which becomes more severe as the
disease progresses.
Cancer of the lungs- caused by small cell (also know as the oat cell) and
spreads very rapidly to other organs. This type is found mainly in
smokers.
Cancer of the larynx- usually found is men over 50 and is usually curable
if found early.
Pulmonary Embolism occurs when a blood clot (embolism) breaks off
and travels to the lung.
Sudden Infant Death Syndrome (SIDS) also known as “Crib Death”
and usually occurs b/w two weeks to one year of age. Infant stops
breathing while asleep. Exact cause is unknown.
The End!!!