Muscle contraction is the tightening, shortening, or lengthening of muscles when you do some activity. It can happen when you hold or pick up something, or when you stretch or exercise with weights.

The contractile responses of esophageal smooth muscle (SM) induced by platelet-activating factor (PAF) involve the activation of L-type voltage-dependent calcium channels (L-type VDCCs), ...

In bronchial asthma, parts of the airways are narrowed. In addition to various symptoms such as increased mucus production and coughing, patients find it difficult to breathe because of the narrowed ...