Chapter 3 Flashcards
According to the Human Tissue Act 65 of 1983, requirements that doctors who diagnose brain dead in a patient must meet if an organ transplant is considered
1- Death must be confirmed by at least two doctors of whom one must be a registered medical practitioner for at least 5 years
2-Nether of the doctors may transplant any tissue taken for a body of this person into the body of a living person, or participate in such transplant
The moment of somatic death is disguised by
1- Discontinuation of circulation, heart no longer pumps
2- Discontinuation of respiration
3- Loss of all reflexes
4- Body relaxation due to loss of muscle tone
5- Changes in the eyes, there is congestion of blood in the veins in the back of the eyeball and later changes occur due to drying out of the cornea
Name the post mortem changes taking place after death
1- Cooling of the body, Algor mortis
2- Post mortem muscle changes, stiffening or so called Rigor mortis followed by secondary muscle flaccidity
3- Post mortem color changes or also known as hypostatic changes, lividity mortis
The post mortem changes taking place later are
1- Decomposition 2- Mummification 3- Adipocere-formation 4- Maceration 5- Skeletalisation
Early post mortem changes, post mortem cooling or Algor Mortis: Heat spread throughout entire body then lost in different processes
Normal oral body temperature: 36-37,2 degrees
Rectal temperature: 0,2-0,4 degrees higher
1- Radiation or emission
2- Conduction from the body to other substances or materials in contact with it
3- Evaporation, mostly perspiration
Name the factors that influence post mortem cooling
1- Initial body temperature 2- External temperature 3- Physical characteristics 4- Body posture 5- Air movement and humidity 6- Clothing and other coverings 7- Medium in which body lies
Post mortem muscle changes. The muscles of the body go through three phases after death
1- Primary muscle flaccidity occurs immediately at death as a result of muscle tone
2- Rigor mortis or post mortem stiffness then follows
3- Secondary muscle flaccidity occurs at onset of the putrefaction process when the muscles start to relax finally and permanently
What are the factors which influence the appearance and disappearance of rigor mortis
1- Temperature
2- Muscle condition at the time of death
Name the specific manifestations
1- Cataleptic stiffening
2- Rigidity due to heat
3- Rigidity due to cold
Pg64
Explain Hypostasis
An hour after death, blood in most bodies becomes permanently fluid because of the release of fibrinolysin from the endothelial lining of the blood vessels. Cells gravitate to the dependent or lowest part of the body. Gravity dependent movement of blood discolors the skin as well as internal organs to a reddish blue color. In hanging position Hypostasis in the hands, forearms and feet or lower legs.
Fluid of blood gravitates to a lesser extent thus causes oedema and later even skin blistering. Sometimes capillary veins rupture and then petechial haemorrhages set in, which can converge and even form blood blisters.
Sometimes color of Hypostasis can be an indication of the possible causes of death
Cherry red- Carbon Monoxide poisoning
Bright rose color- Cyanide poisoning
Green- Hydrogen Sulphate
Rust Brown/ Chocolate brown- Potassium Chlorate poisoning Nitrite Poisoning
Grey bronze- Clostridium Perfringes Septicaemia
Stomach contents can reveal the following information at the post mortem examination
1- What the person ate before death
2- Approximately how long the deceased loved after eating
Digestion process stops after death
Pg71
The rate of putrefaction in a submerged body is determined by
1- The temperature of the medium. Putrefaction occurs more rapidly in warm than cold water
2- The nature of the medium. Putrefaction occurs more rapidly in sewage water that in fresh water as sewage water is usually warmer due to microbiological activity and therefore heat production
3- Movement of the liquid. Putrefaction occurs more rapidly in stagnant water
Post Mortimer observations and interpretation of artefacts
Pg 72-73
What is the difference between somatic death and cellular death
Cellular death is determined by the dependence of the type of tissue, and specifically the cell type, on oxygen and its capacity to function at a low or nonexistent levels of oxygen (hypoxia and anoxia).
Brain death is where no further brain activity or function occurs, and this condition is irreversible and therefore permanent. There is loss of function of the brain stem that maintain and support respiration, cardiac rhythm and integrity of blood circulation.
