Rigor Mortis Research Paper

The anatomy and physiology of the human body explains that muscles are attached to the skeleton. They work like hinges or levers to pull or move particular joints when a muscle contracts, pulling the joint in the direction it is designed to move. Parts of muscles move antagonistically, that is, when one contracts, its opposite member relaxes to allow movement. Muscles can become slack, making movement slower and more difficult.

This activity is the critical driving force of muscle contraction. The stream of action potentials along the muscle fiber surface is terminated as Acetylcholine at the neuromuscular junction is broken down by acetyl cholinesterase. The release of Calcium ions is ceased. The action of the myosin molecule heads is obstructed because of the change in the configuration of troponin and tropomyosin due to the absence of calcium ions. This will eventually cause the contraction to be ceased. Together with these physical processes, an external stretching force such as gravity pulls the muscle back to its normal length.

Once the body took its last breath, a series of things begins to occur. First the body itself shuts down completely. Then soon after the heart stops pumping blood through the body, and because of oxygen loss, cells are dying promptly. Now different cells die at different rates, depending on the importance of the cell, and what the cell is. An example of this is that brain cells within minutes, while the skin can survive over 24 hours after death (What Happens to the Body after Death 1). Due to death the blood of the body, then begins to settle in the closet part to the ground of the body, giving the body discoloration, (typically a grayish white looking tone) and darkening

ATP is required to break the attachment of actin to the myosin head. At death, calcium ions leak out of the SR

c. After about 36 hours, rigor mortis usually disappears in the same sequence as it appeared.

Muscle atrophy is the loss of skeletal muscle mass and function that occurs when there is a long period of inactivity of the muscles or defects in motor neuron's (Reilly, Beau 2015). Defects in the motor neurons that stimulate the muscle cause the muscle mass to decrease as proteins that initiate contractions of muscle dissipate. Stimulus is not transferred to the weakened muscle fibers effectively, reducing the contractile force possible for generation from the stimulus. Muscle mass increases upon recovery, as restimulation of the muscle enlarges fiber size, thus a greater contractile force can be generated from the stimulus.

Rigor Mortis on the other hand is the stiffening of the body due to a loss of ATP from the body’s muscles. All of the muscles are affected at the same time. Rigor mortis occurs normally two hours after death. Once in the phase of rigor mortis, it only lasts about anything from eight hours to twelve hours. Many people think that once the body hits rigor, then it is going to stay that way, however it is the opposite. The body eventually returns to a relaxed state where the muscles will lose the tightness and return back to normal. Rigor mortis has good means of determining time of

Soon after death, anywhere from two to six hours after passing, an event called rigor mortis begins. Rigor mortis is the third stage of death. Rigor mortis is the stiffening or tensing of muscles after death. It is what causes a deceased person's eyelids to open. Rigor mortis is caused by the contraction of muscles in the body immediately after death. It starts with long, narrow bundles of cells that form muscle tissue. These cells build up electric potential by actively pumping out calcium ions. A neuron will release a signal, and when the muscle cells receive it, they open up the calcium channels in their cell membranes. The calcium ions will then rush out through the cell membranes due to the difference in voltage inside and outside of the cell. “Calcium ions will interact with actin and myosin filaments to cause muscle contraction.”(Source 6) Muscles will remain contracted, or in a contracted state, until ATP binds to myosin. When ATP binds to myosin, it releases the myosin and actin from each other, causing the muscles to release. However, when a person is dead they can no longer produce ATP, therefore, the muscles stay clenched. This causes the body to have a sickly stiff appearance. After the muscles have stiffened, the body moves on to the next stage of death.

Denervated muscle undergoes changes that deteriorate the functional outcomes after reinnervation. The main factors are progressive muscle atrophy, loss of functional motor endplates and changes of intramuscular innervation. A denervation period of 6 months leads to a reduced number of muscle fibers, which are smaller in size, and to decreased tetanic force. (Gutmann and Young 1944, Gutmann 1948, Fu and Gordon 1995b) The number of functioning motor endplates after 6 months of denervation is reduced to 75%, which is attributed to atrophy, fibrosis and slow motor endplate regeneration and re-innervation. (Gutmann and Young 1944) Following denervation, intramuscular nerve fibers undergo changes that lead to the outgrowth of axons along the surface of denervated muscle. (Gutmann and Young 1944, Fu and Gordon 1995b) After 8 months of denervation, atrophy results in increasingly poor functional outcomes, as progressive muscle fiber loss occurs. (Gutmann 1948, Irintchev, Draguhn et al. 1990) The loss of muscle satellite cells, which are

Heavy weight on body parts may partially or completely cut off blood flow. Decrease in oxygen supply leads to anaerobic metabolism, skeletal muscle tissue begins to break down. As muscle cells die, they absorb sodium, water and calcium; releases potassium, myoglobin,

known as corpse wax or the fat of graveyards, is a product of decomposition that turns body fat into a soap-like

A post mortem change is the term used to describe any changes which are observed in a subject after death has occurred. Post mortem changes which may be observed in a cadaver include algor mortis, rigor mortis, liver mortis, post mortem blood alterations and subsequent clotting, purification and autolysis (Unknown, 2013). However, histological tissue samples may undergo a series of alterations which causes alterations in tissue structure to occur. Alterations in tissue structure may encourage disparity between expected staining and the subsequent reactions to

riginality does help an essay t o stand out. With this in mind, it is worth rejecting common topics such as euthanasia, legalisation of drugs, drugs in sport , death penalty . . . Apart from their lack of freshness , these topics are very wide and are likely to be covered in a superficial way in 1, 0 00 words. 2.

Both of these muscles expand and contract as they have complex structures so it is essential how they do this. The cardiac muscle needs the contractions to occur in order to pump blood out of the atria and into the ventricles and round the circulatory system so the structure of this muscle shows the systole of the heart. The contractions of the skeletal muscle also depend on its structure. The binding and releasing of two strands of sarcomere is how the repeated pattern of contractions occurs. ATP is used to prepare myosin for binding to allow the contractions to happen. The skeletal and cardiac muscle also both has elasticity. The elasticity is used to restore the muscles back to their original lengths which enable them to resume back to their original length once they have contracted and been stretched.

The last stage is called skeletonization. It lasts months to years. Fat in the body begins to decompose. If a corpse is exposed to soil or cold water, adipocere -