organs of the respiratory system nose pharynx larynx trachea bronchi lungs
TRANSCRIPT
Organs of the Respiratory System
• Nose
• Pharynx
• Larynx
• Trachea
• Bronchi
• Lungs
Accessory Structures
• Thorax
• Diaphragm
The Nose
The nose (naso or rhino) acts as entrance for air and exit for carbon dioxide. A
ciliated epithilial mucus membrane lines the nose and much of the respiratory tract. It serves as a filter for dust and other foreign material. It warms and
moistens entering air and has olfactory receptors
The nostrils (nares) are paired openings. The nostrils vary in
pliability and expandability. The horse has pliable and expandable nostrils because mouth breathing
is not characteristic. The expandability accommodates the
increased need for oxygen
The PharynxThis is a musculomembranous saclike structure. The upper
portion is attached to the base of the skull and the lower portion unites with the esophagus. The pharynx unites with the nasal chambers, mouth, larynx and
eustasian tubes.
The pharynx is divided into three parts:
*nasopharynx*oropharynx
*laryngopharynx
The pharynx is used as passage for both air and food. Depending on the species it may also have a
roll in vocalization
The LarynxThis is commonly called the voice box and is located just below the
pharynx and it serves as a passage for air. The epiglottis is a lid like structure that prevents food from
entering the airway during swallowing
The larynx plays an important role is creating sound. Air passes
through the glottis during expiration causing a vibration,
producing a sound. (video)
The Tracheaalso called the windpipe is a
tube formed of smooth muscle with numerous C shaped rings of cartilage embedded in the tissue. These rings prevent collapse of the structure.
The Bronchithe ends of the trachea separates into smaller airways called the primary
bronchi
The bronchi is lined with a ciliated mucous membrane and have C shaped cartilage rings.
These rings become complete as the bronchi enter the lungs. They then divide into smaller branches
called the secondary branches and these divide into bronchioles which further divide into aveolar
ducts
The aveolar ducts terminate into the aveolar sacs which are
minute, squamous epithelium lined spaces that allow the lungs to achieve the primary function of oxygen and carbon dioxide
exchange.
As the bronchioles get smaller, the cartilage rings begin to
disappear. There are no rings in the aveolar ducts, sacs or aveoli.
The lungs are the primary structures of the respiratory system. The lungs occupy
almost the entire thoracic space. Each lung contains millions of
aveoli and capillaries.
The lungs are encased in a serous membrane called the visceral pleura. The thoracic cavity is lined with another membrane
called the parietal pleura. These membranes reduce the friction
during repiration
The space between these membranes is called the pleural
cavity or potential space.
The thorax (chest cavity) is lined with a membrane similar to the
covering of the lungs. This allows the lubrication of both
surfaces during respiration This membrane is divided into the:
*right pleural cavity*left pleural cavity
*mediastinum
The mediastinum contains the heart, thymus, esophagus,
trachea, bronchi, nerves, arteries, veins and lymphatic vessels.
The Diaphragm:This is a dome shaped
musculomembranous partition separating the thoracic and
abdominal cavity. It attaches to the lumbar and abdominal
cavities. It attaches to the lumbar vertebra, lower ribs and sternum
The diaphragm is the primary muscle of respiration. During
inspiration, it contracts, flattens and lowers. This increases the capacity of the thoracic cavity.
On expiration the diaphragm relaxes and returns to it’s normal
position
Video part 2 and 3
WARNING!!!!
This video of the anatomy of humans….it is graphic.
The process of respiration:The respiratory cycle is divided
into three parts:*inspiration*expiration
*rest : the interval between inspiration and expiration
Respiration involves oxygen being passed throughout the body by circulation and carbon dioxide
wastes being exhaled. The amount of oxygen retained by tissue depends on the need.
Tissue does not store oxygen and tissue only takes in as much
oxygen as it needs.
During exercise the oxygen requirement can be more than
doubled. The flow of air in and out of the lungs depends on
changes in the thoracic cavity. Inspiration and expiration are in
accordance with the pressure differences between the
atmosphere and air in the lungs
Tidal volume (TV):the volume of air inspired or
expired during ordinary respiration
Inspiratory reserve volume (IRV):
the maximum volume of air that can be forcibly inspired in
addition to tidal air.
Expiratory reserve volume (ERV):
the volume of air that can be forcibly expelled in addition to tidal air. Some air will always
be trapped in the alveoli no matter how forcibly an animal
exhales due to intrathoracic pressure.
Residual Volume (RV):The volume of air trapped in the
alveoli
Minimal volume:the small amount of air left in the alveoli after a total lung collapse.
When the thoracic pressure is equal to the atmospheric pressure
Vital capacity (VC):the largest amount of air that can be moved in and out of the lungs.
The sum of the total of inspiratory and expiratory
reserve volumes plus the tidal volume
The nerves from the brain that pass down the chest wall and
diaphragm to control respiration
Vagus nerve:originates in the brain and sends
branches to the larynx, heart, bronchi, esophagus, stomach, liver
and abdomen.
Phrenic nerve:originates in the cervical spine and passes to the diaphragm
Thoracic nerve:originates in the thoracic spinal cord, these are the nerves of the
muscles of the thorax