The respiratory system is a biological system consisting of specific organs and structures used for gas exchange in animals and plants.
The anatomy and physiology that make this happen varies greatly,
depending on the size of the organism, the environment in which it lives
and its evolutionary history.
Restrictive lung diseases are a category of respiratory disease characterized by a loss of lung compliance,
causing incomplete lung expansion and increased lung stiffness, such as
in infants with respiratory distress syndrome. Restrictive lung
diseases can be divided into two categories: those caused by intrinsic
factors and those caused by extrinsic factors. Restrictive lung diseases
yielding from intrinsic factors occur within the lungs themselves, such
tissue death due to inflammation or toxins.
An upper respiratory tract infection (URTI) is an illness caused by an acute infection, which involves the upper respiratory tract, including the nose, sinuses, pharynx, or larynx.
- Lower respiratory tract infection
Lower respiratory tract infection (LRTI) is a term often used as a synonym for pneumonia but can also be applied to other types of infection including lung abscess and acute bronchitis. Symptoms include shortness of breath, weakness, fever, coughing and fatigue. A routine chest X-ray is not always necessary for people who have symptoms of a lower respiratory tract infection.