Kematian 7 - Death - 死亡 - Sǐwáng
Stages of death
Cessation of breathing
Cardiac arrest (No pulse)
Pallor mortis
Algor mortis
Rigor mortis
Livor mortis
Putrefaction
Decomposition
Skeletonization
Cardiac arrest (No pulse)
Pallor mortis
Algor mortis
Rigor mortis
Livor mortis
Putrefaction
Decomposition
Skeletonization
Gagal jantung (Cardiac arrest)
Gagal jantung adalah pemberhentian sirkulasi normal darah dikarenakan kegagalan dari ventrikel jantung untuk berkontraksi secara efektif pada saat systole. Akibat kekurangan penyediaan darah, menyebabkan kematian sel dari kekurangan oksigen. Cerebral hypoxia, atau kekurangan penyediaan oksigen ke otak, menyebabkan korban kehilangan kesadaran dan berhenti bernafas dengan tiba-tiba.
Simtoma paraklinis yang ditemukan pada gagal jantung terutama adalah disfungsi sel jantung, antara lain mekanisme pembersihan kalsium dari sitoplasma, defisiensi retikulum sarkoplasma beserta protein transpor Ca-ATPase dan regulator fosfolamban.[1]
Gagal jantung adalah gawat medis yang bila dibiarkan tak terawat akan menyebabkan kematian dalam beberapa menit. Perawatan pertama utama untuk gagal jantung adalah cardiopulmonary resuscitation.
Etiology
Penyakit arteri koroner (Coronary artery disease, CAD) adalah proses penyakit kebanyakan yang dihubungkan dengan kematian jantung mendadak di Amerika Serikat. Kejadian CAd dalam individu yang menderita kematian jantung mendadak adalah antara 64 dan 90%.
Pallor mortis
Pallor mortis (Latin for paleness of death) is a postmortem paleness which happens in those with light skin almost instantly (in the 15–120 minutes after the death) because of a lack of capillary circulation throughout the body. The blood sinks down into the lower parts (according to gravity) of the body creating the livor mortis.
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 was found very quickly after death.
Also, a living person can look death-pale. This can happen when the circumstances make the blood escape from the surface of the skin, as in deep shock. Also heart failure (Insufficientia cordis) can make the face look gray; the person then also has blue lips.
Livor mortis
Livor mortis adalah salah satu tanda kematian, yaitu mengendapnya darah ke bagian bawah tubuh, menyebabkan warna merah-ungu di kulit. Karena jantung tidak lagi memompa darah, sel darah merah yang berat mengendap di bawah serum karena gravitasi bumi. Warna ini tidak muncul di daerah-daerah yang berhubungan dengan benda lain karena kapilari tertekan.
Koroner dapat menggunakan hal ini untuk menentukan waktu kematian. Livor mortis dimulai sekitar 20 menit sampai 3 jam setelah kematian.
Algor mortis
Algor mortis (Latin: algor—cold(ness); mortis—of death) is the reduction in body temperature following death. This is generally a steady decline until matching ambient temperature, although external factors can have a significant influence.
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° Celsius during the first hour and 1° Celsius per hour until the body nears ambient temperature.
The Glaister equation[1][2] estimates the hours elapsed since death as a linear function of the rectal temperature:
- (36.9 °C - [rectal temperature in Celsius]) ×1.2
As decomposition occurs the internal body temperature tends to rise again.
Kaku mayat
Rigor mortis atau kaku mayat terjadi akibat hilangnya ATP. ATP digunakan untuk memisahkan ikatan aktin dan myosin sehingga terjadi relaksasi otot. Namun karena pada saat kematian terjadi penurunan cadangan ATP maka ikatan antara aktin dan myosin akan menetap (menggumpal) dan terjadilah kekakuan jenazah. Rigor mortis akan mulai muncul 2 jam postmortem semakin bertambah hingga mencapai maksimal pada 12 jam postmortem. Kemudian setelah itu akan berangsur-angsur menghilang sesuai dengan kemunculannya. Pada 12 jam setelah kekakuan maksimal (24 jam postmortem) kaku jenazah sudah tidak ada lagi. Faktor-faktor yang memengaruhi terjadinya kaku jenazah adalah suhu tubuh, volume otot dan suhu lingkungan. Makin tinggi suhu tubuh makin cepat terjadi kaku jenazah. Rigor mortis diperiksa dengan cara menggerakkan sendi fleksi dan antefleksi pada seluruh persendian tubuh.
Hal-hal yang perlu dibedakan dengan rigor mortis atau kaku jenazah adalah:
- Cadaveric Spasmus, yaitu kekakuan otot yang terjadi pada saat kematian dan menetap sesudah kematian akibat hilangnya ATP lokal saat mati karena kelelahan atau emosi yang hebat sesaat sebelum mati.
- Heat stiffening, yaitu kekakuan otot akibat koagulasi protein karena panas sehingga serabut otot memendek dan terjadi flexi sendi. Misalnya pada mayat yang tersimpan dalam ruangan dengan pemanas ruangan dalam waktu yang lama.
- Cold stiffening, yaitu kekakuan tubuh akibat lingkungan yang dingin sehingga terjadi pembekuan cairan tubuh dan pemadatan jaringan lemak subkutan sampai otot.
Putrefaction
Putrefaction is one stage in the decomposition of the body of a dead animal. It can be viewed, in broad terms, as the decomposition of proteins, in a process that results in the eventual breakdown of cohesion between tissues and the liquification of most organs.
Description
In terms of thermodynamics, all organic tissue is a stored source of chemical energy and when not maintained by the constant biochemical efforts of the living organism it will break down into simpler products. The breakdown of proteins in a decomposing carcass is a spontaneous process but one that is accelerated as the anaerobic microorganisms, already present in the animal's digestive tract when it was alive, consume and digest the proteins that comprise the creature's cells. As cells and their proteins are digested, the tissues of the body are left in a weakened state. Proteins are broken down into smaller components and these are excreted by the bacteria. The excreted components, which include gases and amines such as putrescine and cadaverine, give rise to the putrid odor associated with a decomposing body. The gases are initially constrained within the body cavities but diffuse though adjacent tissues and into the circulatory system. Once within the blood vessels, the gases will then spread to other parts of the body. The result is macroscopically visible bloating of the torso and then the limbs. The increased internal pressure due to the increased volume of gas also helps to weaken and separate tissues. In the end some part of the body will rupture, releasing the gas. As the bacteria consume all available proteins, the process of decomposition progresses into the next stage: skeletonization.
The term decomposition is a generalized expression covering the overall process from the death of the individual until skeletonization of the body. Putrefaction is only one stage of that process. Material that is subject to putrefaction is called putrescible.
Approximate timeline
- 2–3 days: Discoloration appears on the skin of the abdomen. The abdomen begins to swell, due to gas formation.
- 3–4 days: The discoloration spreads and discolored veins become visible.
- 5–6 days: The abdomen swells noticeably, and the skin blisters.
- 2 weeks: The abdomen is bloated; internal gas pressure nears maximum capacity.
- 3 weeks: Tissues have softened. Organs and cavities are bursting. The nails fall off.
- 4 weeks: Soft tissues begin to liquefy, and the face becomes unrecognizable.
The exact rate of putrefaction is dependent upon many factors, such as weather, exposure and location. Thus, refrigeration at a morgue or funeral home can retard the process, allowing for burial in three days or so following death without embalming. The rate increases dramatically in tropical climates.
Research
The University of Tennessee's Forensic Anthropology Facility is a body farm established in 1981 to study human putrefaction. Several others have been built in other locations since that time.
Other uses
In alchemy, putrefaction is the same as fermentation, whereby a substance is allowed to rot or decompose, undisturbed. In some cases, the commencement of the process is facilitated with a small sample of the desired material to act as a "seed".
Pembusukan
Pembusukan jenazah terjadi akibat proses degradasi jaringan karena autolisis dan kerja bakteri. Mulai muncul 24 jam postmortem, berupa warna kehijauan dimulai dari daerah sekum menyebar ke seluruh dinding perut dan berbau busuk karena terbentuk gas seperti HCN, H2S dan lainlain. Gas yang terjadi menyebabkan pembengkakan. Akibat proses pembusukan rambut mudah dicabut, wajah membengkak, bola mata melotot, kelopak mata membengkak dan lidah terjulur. Pembusukan lebih mudah terjadi pada udara terbuka suhu lingkungan yang hangat/panas dan kelembaban tinggi. Bila penyebab kematiannya adalah penyakit infeksi maka pembusukan berlangsung lebih cepat.
Skeletonization (forensics)
In forensics, skeletonization refers to the complete decomposition of the non-bony tissues of a corpse, leading to a bare skeleton. 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, presence of insects, and submergence in a substrate such as water. In the tropics, skeletonization can occur in weeks, while in tundra areas, skeletonization will never occur if subzero temperatures persist. Natural embalming processes in peat bogs or salt deserts can delay the process indefinitely, sometimes resulting in natural mummies.
The rate of skeletonization and the present condition of the corpse can be used to determine the time of death.
After skeletonization has occurred, if scavenging animals do not destroy the bones, the skeleton of mid to large size mammals such as humans takes about twenty years to be completely dissolved by the acids in many fertile soils, leaving no trace of the organism. In neutral pH soil or sand, the skeleton will persist for at least several thousand years before it finally disintegrates. Infrequently, however, the skeleton can undergo fossilization, leaving an impression of the bone that can persist for millions of years.
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