Table 10-3: Postmortem Physical and Chemical Changes

Physical

Algor mortis: physical or chemical change?

Physical

Dehydration: physical or chemical change?

Physical

Hypostasis: physical or chemical change?

Physical

Livor Mortis: physical or chemical change?

Physical

Increase in blood viscosity: physical or chemical change?

Physical

Translocation of microbes: physical or chemical?

Chemical

Rigor mortis: physical or chemical change?

Chemical

Decomposition: physical or chemical change?

Chemical

Postmortem Stain: physical or chemical change?

Chemical

Postmortem Caloricity: physical or chemical change?

Chemical

Shifts in the body pH: physical or chemical change?

Algor Mortis

Slows onset of rigor and decomposition, keeps blood in a liquid state; aids drainage.

Dehydration

Increases blood viscosity, sludge forms. Partly responsible for postmortem edema, increasing preservative demands. Darkens surface areas, cannot be bleached. Eyelids and lips separate, lips and fingers wrinkle. When severe, may retard further decomposition, i.e., desiccation

Hypostasis

Responsible for livor mortis and eventual postmortem stain; increases moisture in dependent tissue areas

Livor mortis

Varies in intensity from slight redness to black depending on volume and blood viscosity; intravascular discoloration, can be cleared; can be set as a sign of arterial solution is used; Keep capillaries expanded, can work as an aid to distribution

Increase in blood viscosity

Clearing serves as a sign of arterial distribution; sludge is created, intravascular resistance; postmortem edema can accompany problem; blood removal becomes difficult; distribution can be poor

Translocation of microbes

Speeds decomposition in various body regions

Rigor mortis

Extravascular resistance; positioning difficult. Features may be hard to pose pH not conductive for good fluid reactions. Tissues swell easily. False sign of preservation (after passage, firming is difficult). Decomposition is usually minimal when present. Increases preservative demand.

Decomposition

Color changes, odor present, purges, skin-slip, & gases (the signs of ______________); poor distributions of solutions, increased preservative demand; rapid swelling in affected tissues.

Postmortem stain

Extravascular, cannot be removed; may be bleached or concealed. Generally noticeable six hours postmortem. Increased preservative demand due to delay interval. Reddish tissues falsely indicate the presence of embalming fluid dyes. Tissues turn gray after embalming, cosmetics correct embalmer’s grey.

Postmortem caloricity

triggers the rigor and decomposition cycles.

Shifts in the body pH

Interferes with embalming fluid-protein reactions; dyes can appear blotchy