Pediatrician, Matigan O'Leary, Intro to Health Occupations

Respiratory System

Responsibilities of the Respiratory System

The respiratory system's responsibility is to take in oxygen and remove carbon dioxide from the body. The body only has a 4-6 minute supply of oxygen so the respiratory system must work continuously.

Organs and Structures

The Respiratory System is made up of many different organs and structures that work together. The nose has two openings which allows air to enter the body. After the nose air then passes the nasal spectrum located inside the nose. The nasal spectrum divides the nose into two hollow spaces. These two hollow cavities are called the nasal cavities. Once in the nasal cavity air then is filtered to trap dust and other particles by the cilia. Cilia also helps to move the mucous layer that lines the airways to push trapped particles toward the esophagus. Sinuses are cavities in the skull that surround the nasal area. They are connected to the nasal cavities by short ducts. The sinuses are also lined with a mucus membrane that warms and moistens the air and provides resonance for the voice. Next is the Pharynx, or throat, it lies directly behind the nasal cavities and gets divided into three sections. The first section is the nasopharynx. The nasopharynx is the upper portion and is located behind the nasal cavities. In the nasopharynx is the pharyngeal tonsils and eustachian tube openings. After the nasopharynx is the oropharynx. This is the middle section and recieves both air from the nasopharynx and food and air from the mouth. The third section is the laryngopharynx or bottom section. The esophagus and trachea branch off of the laryngopharynx. After the pharynx is the larynx or voice box. The larynx lies between the pharynx and trachea, contains the vocal cords, and has nine layers of cartilage. The largest thyroid cartilage is the Adam's apple. Then there is the Epiglottis. The epiglottis is a special leaf-like piece of cartilage that closes the opening into the larynx during swallowing and prevents food and liquids from entering the respiratory tract. From the epiglottis air flows into the trachea which is a tube extending from the larynx to the center of the chest. In the trachea air is carried between the pharynx and bronchi with a series of C-shaped cartilages to help keep the trachea open. The trachea divides into two bronchi which are located in the center of the chest. The right bronchi is shorter, wider, and extends more vertically than the left bronchi. Each of the bronchus enter a lung and carries air from the trachea to the lungs. The bronchioles are branches of the bronchi. Also the alveoli allows oxygen and carbon dioxide to exchange between the blood and the lungs. The lungs are made up of two different lungs. The right lung is made up of the sections: superior, the middle and interior. The left lung only has two sections the superior and inferior. The left lung is smaller because the heart is located toward the left side of the chest and takes up more space. Inside the lungs. Inside the lungs are the pleura, an enclosed membrane, or sac, in each lung.

Process of Breathing

The process of breathing has many parts. The first part would be ventilation. Ventilation is the process of breathing. Ventilation also has two phases: inspiration and expiration. The process of breathing in air is called Ventilation. During this process the diaphragm and inter-costal muscles contract and enlarge the thoracic cavity. This process creates a vacuum. Air is then rushed in through the airways to the alveoli, where gases are exchanged. During expiration the diaphragm and intercostal muscles are relaxed and force air out of the lungs and air passages. Then respiration is the process of inspiration and expiration. Respiration is controlled by the respiratory center of the brain in the medulla oblongata of the brain.

Stages of Respiration

There are three main types of respiration in the body. The first is external respiration. During extrenal respiration the exchange of oxygen and carbon dioxide between the lungs and bloodstream occurs. The next is internal respiration, which is the exchange of oxygen and carbon dioxide between the tissue cells and the bloodstream. The last type is cellular respiration. Cellular respiration happens when oxygen is carried to the tissue cells by the blood. Although, oxygen has a higher concentration in blood than in tissue cells, oxygen leaves the blood capillaries and enters the tissue cells. The cells then use the oxygen and nutrients.


Asthma is a respiratory disorder usually caused by a sensitivity to an allergen such as dust, pollen, medications, or a food. Stress, overexertion and infection can also cause an asthma attack. 7.1 million children under the age of eighteen are affected by asthma. During as asthma attack the walls of the airways are swollen or inflamed. This swelling makes the airways extremely sensitive to irritations and increases your susceptibility to an allergic reaction. As the airways become smaller, less air can pass through them, causing strain on the lungs. Asthma attacks are most common during the night or early morning.

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Human Structure and Function

The type of tissue that is most commonly associated with an asthma attack is smooth muscle tissue. This tissue tightens around the airways during an asthma attack. The lining of the airways also becomes swollen and produces thicker mucus. The respiratory system mainly deals with the Thoracic and abdominal cavities of the body. Also, the respiratory system passes through the right upper quadrant and the left upper quadrant of the body. The respiratory system is located above of the transverse plane and through the frontal plane and the median (midsagittal) plane.

Genetic Testing

Almost half of the children with asthma will continue to have asthma into adulthood.

There is a new study being done by Duke University that is based on a so-called genome wide association studies and will compare those affected by asthma to those who are not to isolated with specific genetic markers that could be associated with the disease. They also believe that a family history of asthma doesn't higher the chances of getting asthma. The researches at Duke University have developed a genetic risk score that is based on fifteen different factors. They then match us the scores to the physical symptoms of asthma over time. Their study was based on 880 patients with all different backgrounds.