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Post-mortem Changes
The stages of death of a human being have medical, biochemical and legal aspects. The term taphonomy from palaeontology applies to the fate of all kinds of remains of organisms. Forensic taphonomy is concerned with remains of the human body. History The academic study of death is called thanatology, a field pioneered by Élie Metchnikoff in the early 20th century. Thanatology focuses on describing postmortem bodily modifications, as well as perspectives concerning psychosocial, medical, ethical, and spiritual aspects of death. Definition of death Prior to the 1980s, the legal standard defined death as the absence of cardiopulmonary function including the loss of all vital signs. However, as medical technology advanced, there were situations where one might lose brain function and maintain cardiopulmonary function. This led the American Medical Association, the American Bar Association in collaboration with the National Conference of Commissioners on Uniform State Laws to com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Jurisprudence
Medical jurisprudence or legal medicine is the branch of science and medicine involving the study and application of scientific and medical knowledge to legal problems, such as inquests, and in the field of law. As modern medicine is a legal creation, regulated by the state, and medicolegal cases involving death, rape, paternity, etc. require a medical practitioner to produce evidence and appear as an expert witness, these two fields have traditionally been interdependent. Forensic medicine, which includes forensic pathology, is a narrower frontline field which involves the collection, documentation, analysis and presentation of objective information (medical evidence) for use in the legal system. When investigating a death, forensic pathologists: * perform autopsies when required * may be appointed as coroners to investigate cases of suspicious death * determine the cause of death and all other factors that relate to the body directly * may attend crime scenes * frequently ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organ Procurement
Organ procurement (also called surgical recovery) is a surgical procedure that removes organs or tissues for reuse, typically for organ transplantation. Procedures If the organ donor is human, most countries require that the donor be legally dead for consideration of organ transplantation (e.g. cardiac death or brain death). For some organs, a living donor can be the source of the organ. For example, living donors can donate one kidney or part of their liver to a well-matched recipient. Organs cannot be procured after the heart has stopped beating for a long time. Thus, donation after brain death is generally preferred because the organs are still receiving blood from the donor's heart until minutes before being removed from the body and placed on ice. In order to better standardize the evaluation of brain death, The American Academy of Neurology (AAN) published a new set of guidelines in 2010. These guidelines require that three clinical criteria be met in order to establish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeletonization
Skeletonization is the state of a dead organism after undergoing decomposition.The Australian Museum. (2018). Decomposition-Body Changes. Retrieved from: https://australianmuseum.net.au/about/history/exhibitions/death-the-last-taboo/decomposition-body-changes/ Skeletonization refers to the final stage of decomposition, during which the last vestiges of the soft tissues of a corpse or carcass have decayed or dried to the point that the skeleton is exposed. By the end of the skeletonization process, all soft tissue will have been eliminated, leaving only disarticulated bones. Timeline In a temperate climate, it usually requires three weeks to several years for a body to completely decompose into a skeleton, depending on factors such as temperature, humidity, presence of insects, and submergence in a substrate such as water. In tropical climates, skeletonization can occur in weeks, while in tundra areas, skeletonization may take years or may never occur, if freezing tempe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decomposition
Decomposition is the process by which dead organic substances are broken down into simpler organic or inorganic matter such as carbon dioxide, water, simple sugars and mineral salts. The process is a part of the nutrient cycle and is essential for recycling the finite matter that occupies physical space in the biosphere. Bodies of living organisms begin to decompose shortly after death. Although no two organisms decompose in the same way, they all undergo the same sequential stages of decomposition. Decomposition can be a gradual process for organisms that have extended periods of dormancy. One can differentiate ''abiotic'' decomposition from ''biotic'' decomposition ( biodegradation); the former means "the degradation of a substance by chemical or physical processes", e.g., hydrolysis; the latter means "the metabolic breakdown of materials into simpler components by living organisms", typically by microorganisms. Animals, such as earthworms, also help decompose the organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retina
The retina (; or retinas) is the innermost, photosensitivity, light-sensitive layer of tissue (biology), tissue of the eye of most vertebrates and some Mollusca, molluscs. The optics of the eye create a focus (optics), focused two-dimensional image of the visual world on the retina, which then processes that image within the retina and sends nerve impulses along the optic nerve to the visual cortex to create visual perception. The retina serves a function which is in many ways analogous to that of the photographic film, film or image sensor in a camera. The neural retina consists of several layers of neurons interconnected by Chemical synapse, synapses and is supported by an outer layer of pigmented epithelial cells. The primary light-sensing cells in the retina are the photoreceptor cells, which are of two types: rod cell, rods and cone cell, cones. Rods function mainly in dim light and provide monochromatic vision. Cones function in well-lit conditions and are responsible fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmoscope
Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope (or funduscope). It is done as part of an eye examination and may be done as part of a routine physical examination. It is crucial in determining the health of the retina, optic disc, and vitreous humor. The pupil is a hole through which the eye's interior can be viewed. For better viewing, the pupil can be opened wider (dilated; mydriasis) before ophthalmoscopy using medicated eye drops ( dilated fundus examination). However, undilated examination is more convenient (albeit not as comprehensive), and is the most common type in primary care. An alternative or complement to ophthalmoscopy is to perform a fundus photography, where the image can be analysed later by a professional. Types There are two major types of ophthalmoscopy: * direct ophthalmoscopy, which produces an upright (unreversed) image of approxim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vital Signs
Vital signs (also known as vitals) are a group of the four to six most crucial medical signs that indicate the status of the body's vital (life-sustaining) functions. These measurements are taken to help assess the general physical health of a person, give clues to possible diseases, and show progress toward recovery. The normal ranges for a person's vital signs vary with age, weight, sex, and overall health. There are four primary vital signs: body temperature, blood pressure, pulse (heart rate), and breathing rate ( respiratory rate), often notated as BT, BP, HR, and RR. However, depending on the clinical setting, the vital signs may include other measurements called the "fifth vital sign" or "sixth vital sign." Early warning scores have been proposed that combine the individual values of vital signs into a single score. This was done in recognition that deteriorating vital signs often precede cardiac arrest and/or admission to the intensive care unit. Used appropriately ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Putrefaction
Putrefaction is the fifth stage of death, following pallor mortis, livor mortis, algor mortis, and rigor mortis. This process references the breaking down of a body of an animal Post-mortem interval, post-mortem. In broad terms, it can be viewed as the decomposition of proteins, and the eventual breakdown of the cohesiveness between tissues, and the liquefaction of most organs. This is caused by the decomposition of organic matter by bacterial or fungal digestion, which causes the release of gases that infiltrate the body's tissues, and leads to the deterioration of the tissues and organs. The approximate time it takes putrefaction to occur is dependent on various factors. Internal factors that affect the rate of putrefaction include the age at which death has occurred, the overall structure and condition of the body, the cause of death, and external injuries arising before or after death. External factors include environmental temperature, moisture and air exposure, clothing, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rigor Mortis
Rigor mortis (), or postmortem rigidity, is the fourth stage of death. It is one of the recognizable signs of death, characterized by stiffening of the limbs of the corpse caused by chemical changes in the muscles postmortem (mainly calcium).Saladin, K. S. 2010. ''Anatomy & Physiology'': 6th edition. McGraw-Hill. In humans, rigor mortis can occur as soon as four hours after death. Contrary to folklore and common belief, rigor mortis is not permanent and begins to pass within hours of onset. Typically, it lasts no longer than eight hours at room temperature. Physiology After death, aerobic respiration in an organism ceases, depleting the source of oxygen used in the making of adenosine triphosphate (ATP). ATP is required to cause separation of the actin-myosin cross-bridges during relaxation of muscle.Hall, John E., and Arthur C. Guyton. Guyton and Hall Textbook of Medical Physiology. Philadelphia, PA: Saunders/Elsevier, 2011. MD Consult. Web. 26 January 2015. When oxyge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algor Mortis
Algor mortis (), the third stage of death, is the change in body temperature post mortem, until the ambient temperature is matched. This is generally a steady decline, although if the ambient temperature is above the body temperature (such as in a hot desert), the change in temperature will be positive, as the (relatively) cooler body equalizes with the warmer environment. External factors can have a significant influence. The term was first used by Bennet Dowler in 1849. The first published measurements of the intervals of temperature after death were done by John Davy in 1839. Applicability A measured rectal temperature can give some indication of the time of death. Although the heat conduction which leads to body cooling follows an exponential decay curve, it can be approximated as a linear process: 2 °C during the first hour and 1 °C per hour until the body nears ambient temperature. The Glaister equation estimates the hours elapsed since death as a linear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Livor Mortis
Livor mortis (), postmortem lividity (), hypostasis () or suggillation, is the second stage of death and one of the signs of death. It is a settling of the blood in the lower, or dependent, portion of the body postmortem, causing a purplish red discoloration of the skin. When the heart stops functioning and is no longer agitating the blood, heavy red blood cells sink through the serum by action of gravity. The blood travels faster in warmer conditions and slower in colder conditions. Livor mortis starts within 20–30 minutes, but is usually not observable by the human eye until two hours after death. The size of the patches increases in the next three to six hours. Fixation will begin to occur during this timeframe, causing the patches to be unaltered due to movement. Maximum lividity will occur between eight and twelve hours after death. Areas of blood pooling in contact with the ground will blanch, or remain white. The blood pools into the interstitial tissues of the bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pallor Mortis
Pallor mortis () is the first stage of death that occurs in those with light/white skin. An opto-electronical colour measurement device is used to measure pallor mortis on bodies. Timing and applicability Pallor mortis occurs almost immediately, generally within 15–25 minutes, after death. Paleness develops so rapidly after death that it has little to no use in determining the time of death, aside from saying that it either happened less than 30 minutes ago or more, which could help if the body were found very soon after death. Cause Pallor mortis results from the collapse of capillary circulation throughout the body. Gravity then causes the blood to sink down into the lower parts of the body, creating livor mortis. Similar paleness in living persons A living person can look deathly pale, with such paleness often likened to death in figurative speech and in fiction. This can happen when blood escapes from the surface of the skin, in a matter of deep shock. Also heart failure ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
