nonpolar covalent bond. (physical chemistry). A bond in which a pair of electrons is distributed or shared equally between two atoms. 1  Facebook.2  Twitter.onpolar covalent bond. (physical chemistry). A bond in which a pair of electrons is distributed or shared equally between two atoms. 1  Facebook.
When is a barrel chest a sign of a disease process? Chronic obstructive pulmonary disease (COPD) is the most common instance in which a barrel chest will occur. In these cases, itâs a sign of the lungs being over-expanded. This is caused by the loss of elasticity and results in the person having hyper-inflated lungs.
What Causes Mucus in the Lungs. COPD means chronic obstructive disease under which two spectrums of diseases are grouped-chronic bronchitis and emphysema. Chronic bronchitis is characterized by over-activity of mucus secreting glands of bronchi which lead to excess secretion of mucus which blocks the bronchioles.While in emphysema it is characterized by over-distension of alveoli and bronchioles.Usually chronic bronchitis and emphysema co-exist.hronic bronchitis is characterized by over-activity of mucus secreting glands of bronchi which lead to excess secretion of mucus which blocks the bronchioles. While in emphysema it is characterized by over-distension of alveoli and bronchioles. Usually chronic bronchitis and emphysema co-exist.