Archive for July, 2007

What Are Smooth (Involuntary) Muscles and Their Functions

Written by admin in July 28th, 2007   Under: Bones, Joints, Muscles and Connective Tissue Diseases, Current Health Articles   Tags: ,    

Characteristics of the Smooth (Involuntary) Muscles

Smooth muscles are present in the iris (pupil contraction), skin (hair muscles that cause goose bumps), walls of vessels and hollow internal organs: the bronchi, lower part of esophagus, stomach, gallbladder, intestine, reproductive and urogenital organs, glands and their ducts. The connective tissue is made up of proteins collagen and elastin. An average smooth muscle cell is 25-50 micrometers long and 2-5 micrometers wide (1 micrometer = 1/1000 of a millimeter). Muscle protein molecules actin and myosin are not organized in sarcomeres, so no striations are visible under a light microscope. Smooth muscle cells are pretty non-organized and meet each other in different angles. In the vessels they are arranged circumferentially, so they can change vessel’s diameter by contracting. Smooth muscles are innervated by the sympathetic and parasympathetic (autonomous) nerves. It takes about 500 ms (one half of a second) for a smooth muscle to reach peak contraction.


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A Brief Introduction on Mesothelioma

Written by admin in July 24th, 2007   Under: Cancer, Current Health Articles   Tags: ,    

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 fiber that is present in the lot of the insulating and the building substances and these fibers 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 fibers 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 fibers, 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 fibers 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.


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