SMC full form in medical term is Smooth Muscle cell. It is a kind of muscle cell that is located in the ramparts of the organs, including respiratory tracts, intestines, stomach, and blood vessels. They are spindle-like in appearance and have a single elongated nucleus. During relaxation and contraction, the configuration of the nuclear membrane in smooth muscle cells alters.
Smooth muscle does not have visible bands of contractile proteins. The contraction of these muscles does not depend on conscious thought and can contract in response to electrical or chemical signals. These signals are received from hormones and autonomic nerves such as vasopressin and epinephrine. Furthermore, they do not have more than one nucleus/per cell.
Smooth muscle cells are essential for the regulation of organ function and diameter. The SMC conducts airflow, blood flow, and the flow of food and waste through the digestive tract. Due to the indispensability of calcium ions for the protein calmodulin, SMC contraction is triggered. However, the instruction of SMC contraction involves multiple pathways and is complex. If the function of SMC becomes abnormal, people will suffer from various diseases, including chronic obstructive pulmonary disease, asthma, etc.