Last of the Lecture notes for 111 (exam 4) Flashcards
One of the basic necessities for bacterial growth, water, has been eliminated from the body.
- Environment- hot dry desert or cold mountainous regions with dehydrated air with perma frost will desiccate bodies.
Permanent Preservation (Mummification)
- Adipose tissue formation
- Facial features swollen beyond recognition
- Intense odor of putrefaction
- Protruding eyes and tongue
- Massive skin slip (desquamation)
- Blue-black streaked with red in color (marbleized)
- Purge from all orifices
- Hair, finger nails, and toe nails have dropped off or are loose.
- Intense odor of ammonia
Characteristics of a wet or dry floater
A fetus dies in the uterus and remains enclosed in the amniotic sac. In a much broader sense, it could refer to the moistening and softening of any tissue decomposing in a liquid medium.
Maceration
The extreme or complete dehydration of a body so as to form a dry, brown, hard structure which is light in weight and resistant to decomposition.
Mummification
A two-step reaction involving the removal of the amino grops from amino acids (refer to protein break down).
Deamination
With the help of oxygen, atoms of carbon and oxygen are pulled off the molecular structure. This reaction is associated with decay.
(removes the carboxyl group from an amino acid)
Oxidative Decarboxylation
A modification of putrefaction which is characterized by the transformation of certain fatty tissues of the body into a substance known as adipocere tissue or grave wax.
Saponification (Adipocere formation)
- Has a greasy, slimey feel.
- It is either pure white or pale yellow in color
- Has the odor of decayed cheese.
- It is highly reisistant to putrefactive organisms. Instead of decomposing, it turns into soap.
- Considered rare
Characteristics of Adipocere
Any substance altering the velocity of a chemical change.
- As one of these, enzymes accelerate or speed up the chemical changes associated with decomposition. These enzymes secreted by the tissue cells are called autolytic enzymes.
Catalyst
- Cupping of the eyeball
- Greenish discoloration over the abdominal area.
- Postmortem stain
- Dehydrated lips and eyelids
1-3 Days
of Putrefaction at 70oF in air
- Purge
- Green discoloration spreading over whole body
- Visceral gas and some tissue gas
- Odor
3-5 Days
Of Putrefaction at 70oF in air
- Tissue gas present in all parts of the body
- Massive skin slip
- Body Swollen
- Starting to turn dark
8-10 Days
Of Putrefaction at 70oF in air
- Bubbles and blisters over the body
- Mottled red, green and brown
- Intense odor of putrefaction
- Nails and hair loose
- Eyes and tongue bulging
- Recognition of features difficult
14-20 Days
Of Putrefaction at 70oF in air
- Thoracic and abdominal cavities may burst open
- Body liquification and gases escaping.
- Feature recognition is impossible
- Bones separating from joints.
1 to 6 Months
Of Putrefaction at 70oF in air
The perfentage of hydrogen ions in concentration, pH may be defined as the degree of acidity or alkalinity of a substance. Simply, pH is a measure of the strength of an acid or base.
- pH scale ranges from 0-14
- 0 is most acid
- 15 is most alkaline or base
pH
The normal pH of blood is 7.4 (7.35-7.45)
During Life
The pH may be as low as 5 to 6.
- 6.3-6.6, slightly acidic, is usually the norm with an average of 6.5
- The acidic tissues do not coagulate well with formalin solutions resulting in a rubber like texture rather than the firmness associated with formaldehyde.
During the maximum stage of rigor mortis
The tissues will return to an alkaline pH and between 7.5-8.5 with 8.0 as a norm, putrefaction will occur.
During advanced decomposition, the pH returns to an alkaline register
Most of these have a slightly alkaline pH. A group of chemicals called buffers are used to control embalming fluid pH and tissue pH.
Embalming Fluids
As the body contains much more protein than carbohydrates, the ammonia by-products resulting from a gradual build up in the tissues of nitrogen products will cause an increase in this.
Formaldehyde Demand
A postmortem stiffening of the body muscles, both voluntary and involuntary, by natural body processes. The stiffening will disappear naturally in a variable period of time as a result of natural body processes. Thus, this is a temporary stiffness of the dead muscle tissue as a result of the coagulation of the muscle juices.
Rigor mortis (Caderveric Rigidity)
The coagulating agent causing rigor mortis is said to be this.
Sarcolactic acid
Glycogen -> Pyruvic Acid = Sarcolactic Acid
Formula for Rigor Mortis
A carbohydrate stored in the muscles and living during life.
Glycogen
In death, an absence of oxygen will cause glycogen to form and release this. This will then break down to form sarcolactic acid.
Pyruvic Acid
Will combine with muscle juices or extracts such as myosinogen and/or paramyosinogen which will cause the formation of insoluble myosin or myosinfibrin resulting in rigor mortis.
Sarcolactic Acid
- It coagulates the soluble muscle juices to form insoluble myosin.
- It causes a swelling of the muscle cell colloid which may be so great as to destroy the structure of muscle cells.
This combination of coagulation and swelling produces the stiffness of the muscles seen in rigor mortis.
The Two Actions Sarcolactic Acid Takes on Muscle Tissues
- Temperature
- Age
- Gender
- Cause and Manner of Death
- Condition of the Muscles
Conditions affecting the onset, duration and termination of Rigor Mortis