week 7 for embalming 1 Flashcards
what is in embalming fluid? (6)
- preservatives
- disinfections
- modifying agents (buffers, anticoagulants, surfactants, humectants, and antiemetics)
- dyes (active and inactive)
- vehicles
- perfuming agents
concentrated preservative chemicals used primarily for arterial embalming
arterial fluid
mixture of arterial fluid and water used for arterial injection with possible inclusion of supplemental fluid
arterial solution
fluids injected for purposes other than preservation and disinfection that will enhance the actions of the arterial solution
supplemental fluids
methylene bridge subcategories (3)
- amines
- amides; peptide
- aldehyde action
purpose of embalming fluid (3)
- “fixes” or coagulates proteins so they cannot further decompose and so they are no longer a source of food for bacteria
- this is done by cross linking those proteins at a methylene bridge
- this is based on the tendency of aldehydes to react with nitrogen
organic compound containing nitrogen with the general formula of R-NH2
- proteins are chemically linked via a reaction with formaldehyde (also forms water)
- cross- linking of two proteins or protein-like substances is done via the methylene bridge
amines
derivative of carboxylic acids in which a hydroxyl group is substituted with an amine or ammonia having the general formula of R-CONH-R’
- protein chains join together by reacting with multiple formaldehyde units via a methylene group
- aldehydes can bridge many peptide sites along a protein chain
- allows for tissues to be tightly linked but also cause tissues to be too firm
amides (peptides)
elements in the methylene bridge (4)
- oxygen (highly electronegative, valence of 6)
- nitrogen (moderately electronegative, valence of 5)
- carbon (moderately electronegative, valence of 4)
- hydrogen (moderately electronegative, valence of 1)
methylene bridge formation (3)
- nitrogen in a protein is bound to two carbons and a hydrogen
- aldehyde molecule enters the body
- nitrogen loses a hydrogen and bonds with the aldehydes carbon
aldehyde action (2)
- cross link reaction between aldehydes and proteins results in dehydration, firmness of tissue, and ultimately preservation
- because of the elongated structure of glutaraldehyde specifically, it doesn’t bridge every peptide linkage along the protein chain
bacteria killing elements (4)
- alcohol
- phenol
- bleach (sodium hypochlorite)
- quaternary ammonium compounds
an organic compound containing one or more hydroxyl (-OH) groups
- disinfectant and antiseptic as well as humectant qualities
- alcohols can denature proteins in bacteria
- efficacy increases in the presence of water
- able to remove water in the bacteria
alcohol
- disinfectant, antiseptic, anti fungal, antiviral
- cauterizing agent, bleaching agent, sometimes used in cavity fluids
- denatures proteins and can get through non polar lipid membranes that protect bacteria
phenol
- oxidizes cell membranes of bacteria leading to cell lysis
- reacts with proteins in blood
- mixing this and embalming chemicals will create noxious gas
bleach (sodium hypochlorite)
surface disinfectants that are generally used for disinfection of skin, oral and nasal cavities, and instruments
- target the cytoplasmic membrane in bacteria
- degrade proteins and nucleic acids
quaternary ammonium compounds
preservatives (3)
- aldehydes
- dialdehydes
- phenol
- formaldehyde is sold as formalin and is very soluble in water
- 37% formaldehyde gas by mass in water or in water/methyl alcohol
- paraformaldehyde - precipitant
- trioxane; another polymer of formaldehyde
aldehydes
dialdehydes (2 subcategories)
- glyoxal
2. glutaraldehyde
- contains small amounts of ethylene glycol, glycolic acid, formic acid, and formaldehyde
- tends to stain tissue yellow
- optimal pH range of 9-10
glyoxal (dialdehydes)
- mild odor, light color
- reacts by cross linking proteins
- wide pH range
- liquid at room temperature
glutaraldehyde (dialdehydes)
- preservative and germicide
- penetrates skin easily and is absorbed by proteins
- strong irritant
- preserves by penetrating the phospholipid bilayer of the cell and dissociating in the cytoplasm of the cell
phenol (presevative)
modifying agents (
- buffers
- humectants
- anticoagulants
- surfactants
- dyes
- anti-endemics
- perfuming agents
- vehicles
- substances capable of maintaining a constant pH by neutralizing both acids and bases
- borates (stabilize formalin, reduce hardening and graying affects of formalin (sodium borate (borax) and boric acid)
- sodium phosphate, citrates, sodium salt of EDTA
- carbonates (sodium carbonate, magnesium carbonate)
buffers
chemicals that increase the capability of tissues to retain moisture
- work by coating formaldehyde molecules, coating sheds off as the tissues become saturated
- glycerol
- sorobitol, glycol
- emulsified oils (lanolin, silicon)
- aloe
- gums (vegetable or synthetic)
humectants
alcohol that increases germ killing capabilities of other chemicals
glycerol
loses water at a slower rate than glycerol, soluble in water
sorbitol, glycol
not water soluble
emulsified oils (lanolin, silicon)
swell and retain moisture when added to water helping to fill out tissues and overcome emaciated appearance
gums (vegetable or synthetic)
chemical agents that retard the tendency of the blood to become more viscous
- keep blood in a liquid state, reduce water hardness, create an alkaline environment
- borates - stabilize formaldehyde as well as reduce coagulation
- EDTA
- Magnesium sulfate, sodium chloride, sodium sulfate, sodium phosphorite, sodium citrate
anticoagulants
chemicals that will reduce the molecular cohesion of a liquid and thereby enable it to flow through smaller openings
- before embalming fluid can circulate throughout the body, any liquid remaining in the capillaries must be cleared
- capillary attraction is the force that holds liquid in the capillary tubes
- if surface tension is lowered, the liquid flows out of the capillaries easily
surfactants (surface tension reducer, wetting agent, penetrating agent)
- chemical structure features one side of the molecule that has a strong affinity for water and another side that has an affinity for non aqueous solutions
- this allows for components like oil and water to mix together more easily
- lowering the surface tension allows the preservative to flow readily and rapidly through the capillaries and into the tissues
- reducing the capillary attraction for blood and other body liquids allows a quick clearing of blood from the capillaries
- increase the ability of fluid to pass through semipermeable capillary walls
surfactants cont’d
- function best in low concentrations
- sodium laurel sulfate, sulfonates
- anionic surfactants are compatible with other anionic surfactants and nonionic compounds
- cationic surfactants are inactivated by anionic compounds
surfactants cont’d