Rigor mortis physiology

• Thick filaments, made of the protein molecule myosin • Thin filaments, made of the protein molecule actin The fibers include other proteins as well, but actin and myosin are at the heart of rigor mortis. When you lift a weight or scratch your head, a Once the actin and myosin molecules stick together, they stay that way until another molecule, adenosine triphosphate (ATP), attaches to the myosin and forces it to let go. Your body uses the oxygen you breathe to help make ATP. That oxygen supply ends, of course, with death. Without ATP, the thick and thin filaments can't slide away from each other. The result is that the muscles stay contracted -- hence rigor mortis. During rigor mortis, another process called autolysis takes place. This is the self-digestion of the body's Although this helps explain why rigor mortis comes and goes, it's the outward appearance -- the relative stiffness of the body -- rather than the process that's of most interest to investigators. Next, we'll explore how the gradual progression of rigor mortis plays a part in Livor and Algor Mortis While the process of rigor mortis is taking place, two other events occur: livor mortis and algor mortis. Livor mortis refers to the maroon or purplish discoloration of the skin that happens when Algor mortis is the gradual cooling of the body until it reaches the same temperature as the air around it.

SKELETAL MUSCLE PHYSIOLOGY NEUROMUSCULAR JUNCTION An important part of understanding the full story of muscle contraction is understanding how a nerve communicates an electrical signal to a muscle fiber. To help with this, you should complete the following steps before reading further. Step 01 Download a page sized image of the Step 02 Complete an Step 03 With your newly labeled image in hand, finish the rest of the reading on this page. To understand how skeletal muscle fibers contract, we need to appreciate the relationship between the electrical event, or excitation, and the mechanical event, or contraction. Let's discuss a true story experienced by Dr. Davis while practicing as a physician. Story Time Dr Davis got a call from the emergency department (ED) at the hospital in Idaho Falls, asking him to come in and see a patient with holes in both ear drums. Perforated tympanic membranes aren't usually a serious emergency, but when the ED doctor told Dr. Davis that the patient had been struck by lightning, he headed right in to the hospital. What had occurred is that the patient was a fly-fishing guide on the South Fork of the Snake River. His clients for the day were a married couple from the east coast. They noticed some lightning and storm clouds in the distance, but weren't too worried. However, a minute or two later there was an ear-shattering crash, and the guide felt like he was grabbed by an immense hand, lifted out of the boat, violently shaken, then slammed back...

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Rigor Mortis Rigor mortis is defined by the decline of ATP to zero, 0% extensibility, an ultimate pH that is reached, and the production of lactic acid that has plateaued. From: Encyclopedia of Food and Health, 2016 Related terms: • Livor Mortis • Resuscitation • Patient • Cadaver • Time of Death • Actin • Rigor • Adenosine Triphosphate M. Tsokos, R.W. Byard, in Encyclopedia of Forensic and Legal Medicine (Second Edition), 2016 Medicolegal Aspects Rigor mortis is occasionally helpful in determining whether a body has been moved after death. If a body is found in an unusual position – for example, one that could not have been maintained under the influence of gravity during primary relaxation of the muscles after death – this position implies that the body has been moved after the development of rigor mortis. Rigor mortis may make examination of the palms and inner aspects of the fingers difficult, so that current marks or defense injuries located here may be overlooked. Marked anal dilatation may be observed postmortem, particularly in children. As previously mentioned, when death occurs and preceding the onset of rigor mortis, the whole body musculature loses its tone. In children, rigor mortis may fix a dilated anal orifice, and this finding may persist after rigor mortis has faded. Anal dilatation is not, therefore, a sufficient marker of penetrative anal abuse. Muscle relaxation immediately after death with opening of the eyes and mouth and subsequent fixation in rigor...