Smooth muscles are in the iris (pupil contraction), skin (hair muscles that cause goose bumps), walls of vessels and hollow internal organs: bronchi, lower part of esophagus, stomach, gallbladder, intestine, reproductive and urogenital organs, glands and their ducts. Connective tissue is made up of proteins: collagen and elastin. Average smooth muscle cell is 25-50 µm long and 2-5 µm wide. Actin and myosin are not organized in sarcomeres so no striations are visible under light microscope. Smooth muscle cells are pretty non-organized and meet each other in different angles. In vessels they are arranged circumferentially and they change vessel’s diameter by contracting. Smooth muscles are innervated by sympathetic and parasympathetic (autonomous) nerves. It takes about 500 ms for a smooth muscle to reach peak contraction.

continue reading Smooth (involuntary) muscles

Causes of Mesothelioma

Before we start off with discussing the disease Mesothelioma, it would be mandatory to pen down that causes. Mesothelioma, as we all know is the most hazardous kind of cancer and is usually caused due to exceeded exposure to Asbestos. Asbestos is a kind of a fibre that is present in the lot of the insulating and the building substances and these fibres are pretty tiny to be seen with the naked eyes. Until the eighties, Asbestos was used in large quantities in the ship building, construction and even some of the household appliances. When this asbestos is moved or accidentally spoiled then it happens to release minute fibres that can be easily breathed into the lungs and can also lead to inflammation, or building up of the tissue also popularized as fibrosis and then finally to mesothelioma, a cancer. It was as recently in the sixties that the initial possible instance between mesothelioma and asbestos was made. Therefore it can be rightly identified as the most frequent cause of the cancer. These asbestos fibres, usually travel through the lungs and settle in the long membrane surrounding the lungs which is also called the pleura. Over period of time, these particles in the lung can cause an assortment of lung diseases and even mesothelioma. These asbestos particles are so tiny that they can even be consumed and a part of these fibres can stick into the digestive track and then after that they can move down to the tissue that borders the peritoneum and cause inflammation there.

continue reading A Brief Introduction on Mesothelioma