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.
âIt is a chronic disease, and it does cause obstruction â¦ and it is a lung disease,â she says. âBut COPD in humans is very different from heaves in horses.â. The leading cause of COPD in humans is cigarette smoking, which causes airway inflammation and damage and produces airway-blocking mucus.