Medicine Microsurgery Sew Small Essays - Surgery,

Medicine: "Microsurgery: Sew Small" A man came into the emergency ward at one o'clock. His thumb came in an hour later. The surgeon's job: get them back together. The successful re-attaching of fingers to hand requires long hours of painstaking work in microsurgery. In the operating room , the surgeon doesn't stand, but sits in a chair that supports her body. Her arm is cradled by a pillow. Scalpels are present as are other standard surgical tools, but the suture threads are almost invisible, the needle thinner than a human hair. And all the surgical activity revolves around the most important instument, the microscope. The surgeon will spend the next few hours looking through the microscope at broken blood vessels and nerves and sewing them back together again. The needles are so thin that they have to be held with needlenosed jeweller's forceps and will sew together nerves that are as wide as the thickness of a penny. To make such a stitch, the surgeon's hands will move no more than the width of the folded side of a piece of paper seen end on! Imagine trying to sew two pieces of spaghetti together and you'll have some idea of what microsurgery involves. Twenty-five years ago, this man's thumb would have been lost. But in the 1960s, surgeon's began using microscopes to sew what previously had been almost invisible blood vessels and nerves in limbs. Their sewing technique had been developed on large blood vessels over a half century earlier but could not be used in microsurgery until the needles and sutures became small enough. The surgical technique, still widely used today, had taken the frustrating unreliability out of sewing slippery, round-ended blood vessels by ingeniously turning them into triangles. To do this, a cut end of a blood vessel was stitched at three equidistant points and pulled slightly apart to give an anchored, triangular shape. This now lent itself to easier, more dependable stitching and paved the way for microsurgery where as many as twenty stitches will have to be made in a blood vessel three millimetres thick. The needle used for this can be just 70 millimetres wide, only ten times the width of a human blood cell. All this technology is focused on getting body parts back together again successfully. The more blood vessels reattached, the better the survival chances for a toe or a finger. The finer the nerve resection, the better the feeling in a damaged part of the face, or control in a previously useless arm. But the wounded and severed body part must be treated carefully. If a small part of the body, such as a finger is cut off, instead of torn, wrapped in a clean covering, put on ice and then reattached within a few hours, the chance of success is over ninety percent, as long as one good artery and one good vein can be reattached. Not only is micro surgery allowing body parts to be reattached, it's also allowing them to be reshuffled. Before 1969, nothing could be done for you if you'd had your thumb smashed beyond repair. But in the past 14 years, you would have been in luck, if your feet were intact. Every year in North America, hundreds of big toes are removed from feet and grafted onto hands. Sometimes tendons are shifted from less important neighbouring fingers to allow the thumb to work better in its unique role of opposing the other fingers and allowing us to grip. While we in North America can live without our big toes and never really miss them, people in Japan can't. They need their big toes to keep the common footwear, the clog, on their feet. So their second toe is taken instead. Farmers, labourers car accident victims and home handymen are the people most often helped by microsurgery replants. And because blood vessels are being reattached, burn victims can now benefit. Flaps of their healthy skin are laboriously reattached more successfully, blood vessel by blood vessel, to increase chances that the graft will take. Some women, whose diseased Fallopian tubes have become blocked, can have them reopened microsurgically. When a cancerous esophagus must be removed, it can

Research and theories of sleep essays

Research and theories of sleep essays To talk about a concept, we must first be clear on its definition. Psychologists describe sleep as an altered state of consciousness. It is a resting state in which an individual becomes relatively quiescent and relatively unaware of the environment. During sleep, which is in part a period of rest and relaxation, most physiological functions such as body temperature, blood pressure, and rate of breathing and heartbeat decrease. The amount of sleep needed depends on both the individual and the environment. With the invention of the Electroencephalogram or an EEG as it is more commonly known has made it possible to monitor the brain's electrical activity. The EEG picks up and records electrical activity through electrodes attached to the scalp. The reading of a waking person is clearly different than that of a sleeping person. The EEG pattern of our brain during waking periods is very rapid, irregular and low on voltage. This means that many neurons are firing at different intervals and at different times, with different strengths too. This type of irregular electrical activity in the brain during wakefulness is called beta waves or beta activity. When we are relaxed, sitting in the sofa watching T.V. without any mental arousal, the EEG records a waveform called alpha waves or alpha activity, slower than beta waves. These two waves (alpha and beta) represent the irregular firing pattern of large areas of the brain. Brain activity is desynchronised while in alpha and beta activity. Sleep on the other hand is not a random process; instead, it is a very organized one. Through EEG readings Sleep has been separated into five stages. Stage 1-4 (non-REM sleep) followed finally by REM sleep. Once REM sleep is achieved, the cycle reverses itself and goes back though stages IV, III, II and again to III, IV and REM. Throughout the night, this cycle occurs at 90 to 100 minute intervals. ...