Pulmonary Structure and Functions
The respiratory system consists of nose, pharynx, larynx, trachea, bronchi, and lungs.
Primary, secondary, tertiary bronchi. Terminal and respiratory bronchioles. Alveolar ducts.
With branching supportive cartilage is gradually replaced by smooth muscle.
They are small, thin walled sacs that have capillary bed in their walls. They are sites of gas
molecules that exchange between air and blood. Alveoli have high surface area, with very thin
cell walls to allow for better exchange.
Contraction and relaxation of bronchi constrict or dilates the bronchioles which have affect on
the airway resistance.
Lungs contains conducting airways, alveoli, blood vessels, and elastic tissue.
The Boyle's law explains the pressure is inversely proportional to its volume.
Air moves according to the pressure differences. Air will move from high pressure to low
Inspiration is an active process when the diaphragm descends and the muscle that surrounds
the ribs are contracting thus increasing the volume of the thoracic cavity which decrease the pressure inside the lungs dropping it 1-2 mm Hg. This causes the air to flow into the lungs
because of the pressure differences.
During exercise the inspiratory muscle work harder that can produce a larger negative pressure
to bring more oxygen into the lungs. Also mouth breathing tends to replace nasal breathing
because of l