Rigor mortis

Rigor mortis (Latin: rigor "stiffness", mortis "of death"), or postmortem rigidity, is the third 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.[1] In humans, rigor mortis can occur as soon as four hours after death.

Physiology

After death, 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.[2] When oxygen is no longer present, the body may continue to produce ATP via anaerobic glycolysis. When the body's glycogen is depleted, the ATP concentration diminishes, and the body enters rigor mortis because it is unable to break those bridges.[3]

Additionally, calcium enters the cytosol after death. Calcium is released into the cytosol due to the deterioration of the sarcoplasmic reticulum. Also, the breakdown of the sarcolemma causes additional calcium to enter the cytosol. The calcium activates the formation of actin-myosin cross-bridging. Once calcium is introduced into the cytosol, it binds to the troponin of thin filaments, which causes the troponin-tropomyosin complex to change shape and allow the myosin heads to bind to the active sites of actin proteins.[1] In rigor mortis myosin heads continue binding with the active sites of actin proteins via adenosine diphosphate (ADP), and the muscle is unable to relax until further enzyme activity degrades the complex.[2]

Normal relaxation would occur by replacing ADP with ATP, which would destabilize the myosin-actin bond and break the cross-bridge.[1] However, as ATP is absent, there must be a breakdown of muscle tissue by enzymes (endogenous or bacterial) during decomposition. As part of the process of decomposition, the myosin heads are degraded by the enzymes, allowing the muscle contraction to release and the body to relax.[4][5] Decomposition of the myofilaments occurs 48 to 60 hours after the peak of rigor mortis, which occurs approximately 13 hours after death.[1]

Physical changes

At the time of death, a condition called "primary flaccidity" occurs. Following this, the muscles stiffen in rigor mortis. All muscles in the body are affected. Starting between two and six hours following death, rigor mortis begins with the eyelids, neck, and jaw. The sequence may be due to different lactic acid levels among different muscles, which is directly related to the difference in glycogen levels and different types of muscle fibers.

Rigor mortis then spreads to the other muscles, including the internal organs, within the next four to six hours. The onset of rigor mortis is affected by the individual's age, sex, physical condition, and muscular build. Rigor mortis may not be perceivable in many infant and child corpses due to their smaller muscle mass.[6]

Applications in meat industry

Rigor mortis is very important in meat technology. The onset of rigor mortis and its resolution partially determine the tenderness of meat. If the post-slaughter meat is immediately chilled to 15 °C (59 °F), a phenomenon known as cold shortening occurs, whereby the muscle sarcomeres shrink to a third of their original length.

Cold shortening is caused by the release of stored calcium ions from the sarcoplasmic reticulum of muscle fibers, in response to the cold stimulus. The calcium ions trigger powerful muscle contraction aided by ATP molecules. To prevent cold shortening, a process known as electrical stimulation is carried out, especially in beef carcasses, immediately after slaughter and skinning. In this process, the carcass is stimulated with alternating current, causing it to contract and relax, which depletes the ATP reserve from the carcass and prevents cold shortening.[7]

Application in forensic pathology

The degree of rigor mortis may be used in forensic pathology, to determine the approximate time of death. A dead body holds its position as rigor mortis sets in. If the body is moved after death, but before rigor mortis begins, forensic techniques such as livor mortis can be applied. If the position in which a body is found does not match the location where it is found (for example, if it is flat on its back with one arm sticking straight up), that could mean someone moved it.

Several factors also affect the progression of rigor mortis, and investigators take these into account when estimating the time of death. One such factor is the ambient temperature. In warm environments, the onset and pace of rigor mortis are sped up by providing a conducive environment for the metabolic processes that cause decay. Low temperatures, however, slow them down. Therefore, for a person who dies outside in frozen conditions rigor mortis may last several days more than normal, so investigators may have to abandon it as a tool for determining time of death.[8][9]

See also

References

  1. ^ a b c d Saladin, K.S. 2010. Anatomy & Physiology: 6th edition. McGraw-Hill.
  2. ^ a b Hall, John E., and Arthur C. Guyton. Guyton and Hall Textbook of Medical Physiology. Philadelphia, PA: Saunders/Elsevier, 2011. MD Consult. Web. 26 Jan. 2015.
  3. ^ Fremery, Donald (3 February 1959). "Biochemistry of Chicken Muscle as Related to Rigor Mortis and Tenderization". Journal of Food Science. 25 (1): 73–87. doi:10.1111/j.1365-2621.1960.tb17938.x.
  4. ^ "About.com".
  5. ^ "Classroom Resources - Argonne National Laboratory".
  6. ^ "Rigor Mortis and Other Postmortem Changes - Burial, Body, Life, Cause, Time, Person, Human, Putrefaction." Encyclopedia of Death and Dying. 2011. Web. 4 December 2011. <http://www.deathreference.com/Py-Se/Rigor-Mortis-and-Other-Postmortem-Changes.html>.
  7. ^ The Royal Society of New Zealand (1976). "New Zealand Journal of Agricultural Research". The Royal Society of New Zealand. p. 13.
  8. ^ Peress, Robin. "Discovery Health "Rigor Mortis at the Crime Scene"" Discovery Health "Health Guides" Discovery Fit & Health, 2011. Web. 4 December 2011. <http://health.howstuffworks.com/diseases-conditions/death-dying/rigor-mortis-cause2.htm>
  9. ^ Estimating The Time of Death, ExploreForensics <http://www.exploreforensics.co.uk/estimating-the-time-of-death.html

Bibliography

  • Bear, Mark F; Connors, Barry W.; Paradiso, Michael A., Neuroscience, Exploring the Brain, Philadelphia : Lippincott Williams & Wilkins; Third Edition (1 February 2006). ISBN 0-7817-6003-8
  • Robert G. Mayer, "Embalming: history, theory, and practice", McGraw-Hill Professional, 2005, ISBN 0-07-143950-1
  • "Rigor Mortis and Other Postmortem Changes - Burial, Body, Life, Cause, Time, Person, Human, Putrefaction." Encyclopedia of Death and Dying. 2011. Web. 4 December 2011. <Rigor Mortis and Other Postmortem Changes - burial, body, life, cause, time, person, human, Putrefaction>.
  • Saladin, Kenneth. Anatomy and Physiology: The Unity of Form and Function, 6th ed. McGraw-Hill. New York, 2012.
  • Peress, Robin. "Discovery Health "Rigor Mortis at the Crime Scene"" Discovery Health "Health Guides" Discovery Fit & Health, 2011. Web. 4 December 2011. <What causes rigor mortis?>.
33rd Hong Kong Film Awards

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8th Asian Film Awards

The 8th Asian Film Awards are the 2014 edition of the Asian Film Awards. The ceremony was held in Macau.

Bruce Corbitt

Bruce Kendall Corbitt (December 22, 1962 – January 25, 2019) was an American heavy metal vocalist from Dallas, Texas, best known for alternately fronting the bands Rigor Mortis and Warbeast. His aggressive vocals were first showcased on Rigor Mortis’ self-titled debut, which was released by Capitol Records in 1988. The album is regarded as a landmark of speed metal, and the band is one of the first of its type to have a major label release.

Cadaveric spasm

Cadaveric spasm, also known as postmortem spasm, instantaneous rigor, cataleptic rigidity, or instantaneous rigidity, is a rare form of muscular stiffening that occurs at the moment of death and persists into the period of rigor mortis. Cadaveric spasm can be distinguished from rigor mortis as the former is a stronger stiffening of the muscles that cannot be easily undone, as rigor mortis can.The cause is unknown but is usually associated with violent deaths under extremely physical circumstances with intense emotion.

Cardiac Arrest (album)

Cardiac Arrest is the first album by the funk/R&B band Cameo.

The album reached #16 on the R&B charts and contained the hit single "Rigor Mortis".

Darkcutter

A darkcutter or dark cutter is a carcass of beef that has been subjected to undue stress before slaughter, and is dark in color. Sometimes referred to as dark cutting beef, they have a dark color which makes the meat appear less fresh, making them undesirable to consumers. Darkcutters fetch a lower price than otherwise ordinary beef on the market.

Stress ante mortem causes a depletion of glycogen stores in the liver and muscles, so the glucose normally used post mortem to produce ATP anaerobically, resulting in lactic acid production before the development of rigor mortis, is not available. The muscle pH stays high (above 6.0), resulting in higher water-holding capacity (sticky protein) and more translucent muscle, which looks darker because light travels deeper into the muscle before being refracted.

League of Blind Women

League of Blind Women was a short-lived alternative rock supergroup that included Rob Buck (lead guitar) from 10,000 Maniacs, Jerry Augustyniak (drums) from 10,000 Maniacs, Casey Orr (bass) from Gwar and Rigor Mortis, Mike Scaccia (guitar) from Ministry and Rigor Mortis, Kol Marshall (keyboards) from Critical Mass and See No Evil, and Chris Kelly (vocals). When Casey Orr left the band in March 1999 to return to Gwar, Mitch Marine from Tripping Daisy took his place on bass. Dave Dunn played drums with the band after Jerry Augustyniak left.

The band produced two known sets of demos, a five-song EP and an additional song later on. They recorded at least some of their material at Nomad Studio in Carrollton, Texas.

Buck left 10,000 Maniacs for several months in 1998-1999 to concentrate on League of Blind Women and was replaced in the Maniacs by Michael Lee Jackson of the band Animal Planet. Jackson returned to Animal Planet. Buck returned to 10,000 Maniacs in 1999 and it was apparent he was ill. Buck died on December 19, 2000 of liver failure.In 2001, League of Blind Women released the five-song EP League of Blind Women. Credits say it featured Chris Kelly on vocals, Mike Scaccia on guitars, and Kol Marshall on keyboards, but these were slightly remixed versions of the demos that had been recorded featuring Rob Buck on guitar.

Mike Scaccia

Michael Ralph Scaccia (June 14, 1965 — December 23, 2012) was an American musician, best known as the lead (and sometimes rhythm) guitarist for several heavy metal and alternative rock acts, including Rigor Mortis, Ministry and Revolting Cocks.

Motility

Motility is the ability of an organism to move independently, using metabolic energy. This is in contrast to mobility, which describes the ability of an object to be moved. Motility is genetically determined, but may be affected by environmental factors. For instance, muscles give animals motility but the consumption of hydrogen cyanide (the environmental factor in this case) would adversely affect muscle physiology, causing them to stiffen, leading to rigor mortis. In addition to animal locomotion, most animals are motile (some move by passive locomotion). The term applies to bacteria and other microorganisms, and to some multicellular organisms, as well as to some mechanisms of fluid flow in multicellular organs and tissue. Motile marine animals are commonly called free-swimming, and motile non-parasitic organisms are called free-living.Motility also refers to an organism's ability to move food through its digestive tract. There are two types of intestinal motility – peristalsis and segmentation. This motility is brought about by the contraction of smooth muscles in the gastrointestinal tract which mix the luminal contents with various secretions (segmentation) and move contents through the digestive tract from the mouth to the anus (peristalsis).

Nysten's rule

Nysten's rule (1811) describes the sequential onset of rigor mortis in the various muscle groups. The basic sequence of the solidifying body begins from the head down the body, in the order:

Involuntary muscle first: Heart

Upper eyelidsNeck

Jaw

Face

Upper extremities

Muscles of the trunk

Lower extremitiesThe rule does not occur in all cases, as described. In particular, it depends on what muscle groups are even claimed before the death - there enters rigor mortis then first one.

It owes its name to the French pediatrician Pierre-Hubert Nysten (1771–1818).

Putrefaction

Putrefaction is the fifth stage of death, following pallor mortis, algor mortis, rigor mortis, and livor mortis. This process references the breaking down of a body of a human or animal post-mortem (meaning after death). 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, burial factors, and light exposure.

The first signs of putrefaction are signified by a greenish discoloration on the outside of the skin on the abdominal wall corresponding to where the large intestine begins, as well as under the surface of the liver.

Certain substances, such as carbolic acid, arsenic, strychnine, and zinc chloride, can be used to delay the process of putrefaction in various ways based on their chemical make up.

Body farms are facilities which study the process of human decomposition as well as how environmental factors affect the rate of putrefaction.

Rigor Mortis (album)

Rigor Mortis is the debut album by thrash metal band Rigor Mortis released in 1988 through Capitol Records.

Rigor Mortis (band)

Rigor Mortis was a thrash/speed metal band that formed in 1983 in the Dallas-Fort Worth, Texas metroplex. Two schoolmates, Harden Harrison (drums) and Casey Orr (bass), formed the band when they met Mike Scaccia (guitar). The three young men shared an interest in horror/gore films and very heavy music. With Bruce Corbitt on vocals, they created some of the heaviest thrash metal at the time often flirting with death metal. They were also one of the only major thrash bands from Texas and virtually created the underground metal scene there. The band was signed by Capitol Records in 1987.

In 2005, the original lineup reunited and performed at Ozzfest 2008 in Texas. In 2009, Rigor Mortis played in Germany at the Keep It True Festival.

Mike Scaccia also played guitar with industrial metal band Ministry, Revolting Cocks, Lard, and others.

Casey Orr also plays bass in the shock rock band Gwar, as the character Beefcake the Mighty. He also played bass for Dallas punk rock band The Hellions. He currently plays for Warbeast.

Harden Harrison also plays drums with the metal bands Speedealer and Mitra.

Bruce Corbitt also sang for the thrash metal band Warbeast (Formerly Texas Metal Alliance). The band was signed by Phil Anselmo's label Housecore Records and their debut album Krush The Enemy was released on April 27, 2010. Warbeast's next release was a split album with Philip Anselmo's solo material titled War Of The Gargantuas and was released on January 8, 2013. Warbeast's second full-length album Destroy was released in 2013. Their final album "Enter the Arena", was released on August 4th, 2017.

Former Rigor Mortis vocalist/guitarist Doyle Bright also played guitar in the metal band Hallows Eve. He currently performs vocals and guitars in the band SOG.

Rigor Mortis is featured on the shirt of the creature on the Toxic Holocaust album Evil Never Dies from 2003.

On December 23, 2012, the band's guitarist Mike Scaccia died from a heart attack while performing onstage.On October 6, 2014, Rigor Mortis released their final album Slaves to the Grave, which had been recorded in February 2012 at Ministry's 13th Planet Studios in El Paso. With no label interested in the album, Rigor Mortis successfully crowdfunded the new album by raising $22,838 from fan pre-orders to self-release the final album.After years of battling with cancer, Corbitt died on January 25, 2019 at the age of 56, making him the second member of Rigor Mortis (following Scaccia) to die.The remaining members perform Rigor Mortis music under the moniker Wizards of Gore in tribute to Mike Scaccia.

Rigor Mortis (film)

Rigor Mortis is a 2013 Hong Kong horror film directed by Juno Mak, and also produced by Takashi Shimizu. The film is a tribute to the Mr. Vampire film series. Many of the former cast are featured in this film: Chin Siu-ho, Anthony Chan, Billy Lau and Richard Ng. Additionally, Chung Fat, who starred in Encounters of the Spooky Kind, is also featured.

Rigor Mortis (radio)

Rigor Mortis is a BBC Radio 4 black comedy set in the pathology department at an NHS hospital. It centres on the working lives of the pathologists and attendant staff who work in the department.

Rigor Mortis (song)

"Rigor Mortis" is a song by the funk band Cameo, released on April 20, 1977 in their debut album Cardiac Arrest. In the US, the song peaked at #33 on the Hot Soul Singles chart. ' In this instance "Rigor Mortis" is a euphemism for being lonesome on the dance floor.

Rigor Mortis Sets In

Rigor Mortis Sets In is the third solo album by John Entwistle, who was the bassist for The Who. Distributed by Track Records, the album was named John Entwistle's Rigor Mortis Sets In in the U.S. Co-produced by Entwistle and John Alcock, it consists of three Fifties rock and roll covers, a new version of the Entwistle song "My Wife" from The Who's album Who's Next, and new tracks (only six of the ten songs were new). Rigor Mortis Sets In set in motion John Entwistle assembling his own touring unit during the increasing periods of The Who's inactivity.

Bearing the dedication "In Loving Memory of Rock 'n' Roll 1950–∞: Never Really Passed Away Just Ran Out of Time", Entwistle's affection for Fifties rock and roll was evident by covers of "Mr. Bass Man", "Hound Dog", and "Lucille". As George Lucas had released American Graffiti at the same time as Rigor Mortis Sets In was released, creating a huge market for Fifties nostalgia, Entwistle's timing was uncannily prescient. In Entwistle's original material for the album, light whimsy prevailed over the darker (and more creative) vein of Smash Your Head Against the Wall and Whistle Rymes. The album was completed in less than three weeks, ultimately costing $10,000 in studio time and $4,000 on liquor bills.The cover art of the gatefold LP features on one cover an outdoor photo of a grave, whose heart-shaped headstone is engraved with the dedication described above, while the grave's footstone is inscribed "V.S.O.P." (a grading acronym for cognac). The opposite cover features a wooden coffin bearing a brass plate engraved with the album's name. The UK (Track) LP used the coffin on the cover and the gravestone on the inner gatefold, while the U.S. (MCA) LP had the opposite arrangement. Compact disc releases have been fronted with Track's original coffin cover, with the gravestone cover proportionally preserved inside as part of the liner notes.

Rigor Mortis Sets In had a rough launch due to its title and cover art. BBC Radio refused to play the album and banned it, ironically in part due to the influence of DJ Jimmy Savile who had just suffered a death in his family. The album's U.S. debut was problematic for MCA Records (Track's new American distributor), who insisted on appending the artist's name to the title, out of concern that the album's sales would be weak without the Entwistle name in the title.

Rigor mortis (disambiguation)

Rigor mortis is one of the recognizable signs of death.

It may also refer to:

Rigor Mortis (film), a 2013 film by Juno Mak

"Rigor Mortis" (song), a song by Cameo

Rigor Mortis (band), the thrash metal band

Rigor Mortis (album), a 1988 album by the band

Rigor Mortis (radio), the BBC Radio 4 comedy series

De RigueurMortis a 2001 album by Australian band TISM

Sarcoplasmic reticulum

The sarcoplasmic reticulum (SR) is a membrane-bound structure found within muscle cells that is similar to the endoplasmic reticulum in other cells. The main function of the SR is to store calcium ions (Ca2+). Calcium ion levels are kept relatively constant, with the concentration of calcium ions within a cell being 100,000 times smaller than the concentration of calcium ions outside the cell. This means that small increases in calcium ions within the cell are easily detected and can bring about important cellular changes (the calcium is said to be a second messenger; see calcium in biology for more details). Calcium is used to make calcium carbonate (found in chalk) and calcium phosphate, two compounds that the body uses to make teeth and bones. This means that too much calcium within the cells can lead to hardening (calcification) of certain intracellular structures, including the mitochondria, leading to cell death. Therefore, it is vital that calcium ion levels are controlled tightly, and can be released into the cell when necessary and then removed from the cell.

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