The Primary Function Of The Respiratory System
To oxygenate the blood so that the blood can carry oxygen to all parts of the body
Influenza, Commonly Known As The Flu
A contagious disease that attacks the respiratory system, caused by a virus that commonly mutate and constantly require new vaccinations to prevent the disease from spreading rapidly among human populations
A condition in which the airways are hypersensitive and react to inhaled irritants by narrowing or obstructing
Reduces the elasticity of the lungs, which normally hold the airways open. As the elasticity decreases, the small airways of the lung collapse when the patient breathes out, making it hard to completely exhale.
Larynx (Voice Box)
Controls the volume of inflowing air; produces selected pitch(vibration frequency) in the moving column of air
Distribute air to the alveoli of the lung where the actual external respiration takes place
The main subdivisions of the respiratory system may be identified by their relationship to the voice box or larynx.
as the volume (V) of a gas-filled container increases, the pressure (P) inside decreases; as the volume (V) of a closed container decreases, the pressure (P) inside increases. When two connected spaces of air have different pressures, the air moves from the space with greater pressure to the one with lesser pressure. In regard to breathing, we can consider the air pressure around the human body to be constant. The pressure inside the lungs may be greater or less than the pressure outside the body. Thus, a greater internal pressure causes air to flow out; a greater external pressure causes air to flow in.
The Human Trunk
compared to a hollow cylinder divided into upper and lower cavities by the diaphragm. The upper is the thoracic cavity and is essentially gas-filled. The lower is the abdominopelvic cavity and is essentially water-filled.
Costal (Thoracic) Breathing Inhalation
Muscles attached to the thoracic cage raise the rib cage. A typical rib might be compared to a bucket handle, attached at one end to the sternum (breastbone) and at the other end to the vertebral column. The "bucket handle" is lifted by the overall movement upward and outward of the rib cage. These movements increase the thoracic diameters from right to left (transverse) and from front to back (A-P). Thus, the intrathoracic volume increases. Recalling Boyle's law, the increase in volume leads to a decrease in pressure. The air pressure outside the body then forces air into the lungs and inflates them.
Costal (Thoracic) Breathing Exhalation
The rib cage movements and pressure relationships are reversed for exhalation. Thus, intrathoracic volume decreases. The intrathoracic pressure increases and forces air outside the body.
a thin, but strong, dome-shaped muscular membrane that separates the abdominal and thoracic cavities.
Diaphragmatic (Abdominal) Breathing Inhalation
As the diaphragm contracts, the dome flattens and the diaphragm descends. This increases the depth (vertical diameter) of the thoracic cavity and thus increases its volume. This decreases air pressure within the thoracic cavity. The greater air pressure outside the body then forces air into the lungs.