(Q4) Embalming Chemistry Concepts

Question 1

Primary Disinfection

Answer 1

• Disinfection done before the embalming procedure begins
• May consist of cleaning the deceased; cleaning the eyes, mouth, or orifices

Question 2

Concurrent Disinfection

Answer 2

• Disinfection during the embalming operation
• Disinfection that occurs during injection and cavity embalming

Question 3

Terminal Disinfection

Answer 3

• Disinfection after the embalming operation to protect the environment
• May consist of cleaning the deceased, cleaning the instruments and the table

Question 4

The Three Primary Preservative Agents in Embalming Chemicals

Answer 4

• Aldehydes
• Alcohols
• Phenols

Question 5

Five Common Characteristics of All Embalming Chemicals

Answer 5

• Inactivate the chemical groups of proteins or amino acids
• Inhibit further decomposition
• Inactivate enzymes (both of the tissues and microorganisms)
• Kill microorganisms
• Destroy or mask odors and eliminate their further production

Question 6

Inactivate the chemical groups of proteins or amino acids

Answer 6

• The nitrogen in proteins are sites of decomposition
• The chemicals react with the nitrogen to change the structure of the protein (coagulation)
• Coagulation decreases the likelihood that the protein will hydrolyze

Question 7

Inhibit further decomposition

Answer 7

• Chemicals only slow down decomposition
• therefore, embalming as soon as possible is best

Question 8

Inactivate Enzymes

Answer 8

• Enzymes are important catalysts of hydrolysis
• Inactivating the enzymes will slow down decomposition
• enzymes are similar to proteins, so preservative chemicals will inactivate enzymes similar to tissue proteins

Question 9

Kills Microorganisms

Answer 9

• The chemical change that proteins undergo during embalming deprives bacteria of their primary source of nutrition
• Preservative chemicals denature the structural proteins of the bacteria themselves
• The same chemical actions that cause fixation of the tissues of the remains will also produce fixation of the bacterial invaders

Question 10

Destroys/Masks odors and eliminates their further production

Answer 10

• The odors associated with decomposition are principally due to the formation of amines
• The decomposition of structural proteins produces amines such as putrescine, cadaverine, indole, skatole
• Decomposition of sulfur-containing proteins also contributes to odors
• Protein chemicals react with the nitrogen to effectively neutralize the odor
• Preservative chemicals react with the sources of decomposition (putrefactive bacteria and autolytic enzyme) to eliminate the further production of odors

Question 11

Reactions of Formaldehyde and Water

Answer 11

• HCHO and water produce methylene glycol
• The proteins are fixed due to the donation of a methylene group (methylene bridge)

Question 12

Formaldehyde in aqueous solution is:

Answer 12

• formalin
• 37% HCHO by weight
• 40% by volume

Question 13

How are the proteins fixed?

Answer 13

• the donation of a methylene group (-CH2): methyl/methylene bridge

Question 14

Reactions of Formaldehyde with Methanol

Answer 14

• Methanol prevents the polymerization of formaldehyde
• Helps extend shelf life

Question 15

Reactions of Formaldehyde with Proteins

Answer 15

• Main chemical action of HCHO in embalming is the coagulation of protein
• This is brought about by the cross-linking of the peptide bonds of adjacent proteins
• The changes in protein only happen in normal amounts of water; excess water could ever the embalming process by hydrolyzing the cross-links

Question 16

The changes in protein brought about by formaldehyde are

Answer 16

• Viscosity is increased
• Tissues become firmer
• Resistance to digestive enzymes is increased
• Hydrolysis and water solubility are decreased

Question 17

Reactions of Formaldehyde with Amino Acids

Answer 17

• Formaldehyde will react with amino acids similarly to protein, because amino acids are the building blocks of proteins

Question 18

Reactions of Formaldehyde with Strong Bases

Answer 18

• Formaldehyde is destroyed in strong bases

Question 19

What are two of the strong bases produced by decomposition?

Answer 19

Amines and ammonia

Question 20

What implications will amines and ammonia have for embalming?

Answer 20

Because Amines and ammonia are strong bases formed by decomposition, and formaldehyde is destroyed by strong bases
- These strong bases may call for a higher formaldehyde demand to combat them

Question 21

What pH is formaldehyde considered?

Answer 21

a weak acid

Question 22

Reactions of Formaldehyde with Hemoglobin

Answer 22

• Formaldehyde and hemoglobin produce methemoglobin
• Methemoglobin can turn the body black in 2-3 days
• Preventing the over-formation of methemoglobin is another reason for drainage

Question 23

Preservative Demand/Formaldehyde Demand

Answer 23

• The amount of formaldehyde/preservative necessary to overcome any nitrogen residue and cause the body proteins to become coagulated
• The total amount of formaldehyde with which protein will combine to be completely preserved
• The greater the decomposition, the greater the formaldehyde demand

Question 24

Walling-Off Action

Answer 24

• When the concentrated solution seals and sear the capillaries in the tissues preventing distribution and diffusion of the fluid
• causes “shell embalming”
• Caused by too concentrated solutions of formaldehyde or too high rate of flow

Question 25

What is "shell embalming"

Answer 25

When the embalming solution follows the direct connections between the arterioles and venules and only the surface receives embalming solution, giving a false impression to the embalmier

Question 26

Distribution

Answer 26

- The movement of arterial solution from the point of injection throughout the arterial system to the arteries. - **Solution moves from carotid (or other injection vessels) to the rest of the arteries**

Question 27

Diffusion

Answer 27

- The movement of arterial solution from inside the vascular system (intravascular) through the walls of the capillaries to the tissues (extravascular - **(after it gets to the other arteries) Solution moves into the capillaries where it disperses to the tissues**