When You Can’t Catch Your Breath
Any problem that reduces the efficiency or the ease with which gases can be exchanged between the blood and the lungs will wreak havoc on all systems of the body. Sometimes disease and infections, like pneumonia and bronchitis, can temporarily cause respiratory difficulties. Other diseases are longer-term and cannot be cured.
Anatomy of a Word
hypoxia
Hypoxia is reduced oxygen levels in the blood. It leads to increased respiratory and cardiac rates in an attempt to compensate for this condition. However, this requires more energy and more oxygen, and cannot be maintained as a normal level of physiological function.
Respiratory Distress Syndrome
Respiratory distress syndrome (RDS) occurs in newborns, especially premature infants, because of an insufficient production of surfactant. Type II pneumocytes normally begin producing substantial levels of surfactant in the last few weeks of pregnancy, which is required to keep the alveoli open and functional. If babies are born too early, before surfactant levels are optimal, the alveoli are unable to remain open and much less air fills this level of the respiratory zone where the bulk of external respiration occurs.
How is RDS treated?
To treat infants with respiratory distress syndrome, exogenous (artificial) surfactant is administered into the airway and lungs of the infant in order to open as many alveoli as possible. This continues until the baby’s own body is capable of making enough surfactant.
Asthma
This is a chronic obstructive disorder that makes it difficult to breathe. Triggered by either allergic or inflammatory immune mediators, the smooth muscle of the bronchioles spasmodically and involuntarily constricts and reduces the flow of air into the lungs. Wheezing and shortness of breath result, but can be reversed by blocking beta 2 adrenergic receptors in the airway, thus mimicking an autonomic nervous system response that dilates the bronchioles.
Emphysema
Emphysema is a nonreversible destruction of lung tissue, specifically alveoli. Any damage, environmental or otherwise, that causes the death of type I pneumocytes and their replacement by connective tissue cells (scar tissue) reduces the efficacy of the lung tissue. The symptoms are similar to those of other respiratory disorders and, unlike asthma, are irreversible and permanent.
Chronic Obstructive Pulmonary Disease (COPD)
COPD is an obstructive disease that makes breathing difficult. It has claimed an increasing number of lives in Western cultures as a result of smoking tobacco (smoking is the number one cause of COPD worldwide). This disease is somewhat of a combination of asthma and emphysema. It begins with lung irritation, primarily from smoke, and leads to an immune response and inflammation. Chronic exposure of the lung tissue to the harsh chemicals in the smoke results in chronic inflammation and a reflex bronchospasm response.
However, unlike asthma, these constrictions of the airway are poorly reversible and permanent in nature. If the environmental stressors are not eliminated, the reduced airflow leads to the destruction of alveolar tissue (emphysema). Together the asthma-like reduced airflow and emphysema compose the major problems involved in COPD, which is extremely difficult to treat.
Cystic Fibrosis
Cystic fibrosis is a genetic disorder that primarily affects the lungs but also affects other organs of the body, such as the pancreas and kidneys. A thick, sticky mucus forms in these organs. In the case of the lungs, the mucus makes it difficult to breathe, interferes with the effective exchange of gases, and causes lung damage. There is no cure, and treatment focuses on preventing lung infections and loosening and removing the mucus. Life expectancy for individuals with this disease has increased in recent years but it is still a life-threatening condition.