ANAT303 SUMMARY

Rigor mortis- process that cause muscles in the body to stiffen, resulting in rigidity. DH rules : - PRIVACY

  • RESPECT
  • SAFETY
  • SECURITY

CHEMICALS USED IN THE LAB: Methanol, phenol, thymol, formalin, glycerol, ethanol

DECALCIFICATION – REMOVAL OF CALCIUM

CRITERIA FOR GOOD DECALFICATION:

  1. Complete removal of calcium
  2. Absence of damage tissues
  3. Reasonable speed of decalcification.

FACTORS INFLUENCING THE RATE OF DECALCIFICATION: 1.Concentration of decalcifying agent —increase volume of decalcifying agent, increase of calcium removal. 2.Temparature – increase in temperature, increase of decalcification process. 3.Renewal fluid4.Agitating.

“The existence of human skeletons in such collections is crucial for the teaching of human anatomy, including dental anatomy, students of medicine, dentistry, physiotherapy, occupational therapy, nursing and pharmacy; as well students of comparative anatomy, primatology and general morphology”. Philip Tobias

in the 20th century: benzene , however, has proven to be highly toxic & not used now----ROBERT J. COLLECTION

HR SKILLER – 1926 , A method for preparation of skeletons preserved by phenol.

QUICK ACTING FORMULA ( ANTI- FORMIN)• They state that “the five-step method of maceration, cleaning, degreasing, bleaching, and fixing as well as the use of dermestid beetles are, in effect, not necessary. Snyder, Burdi, and Gaul, 1975

DECALFICATION SOLUTION: 88% Formic acid -100 ml Hydrochloric acid – 80 ml distilled water – 820 ml

Solution changed every 8 hours, temperature between 30-40 degrees Celsius.

  • MICROTOMY : Optimal sectioning thickness 4- 7 μm.

MOUNTS AND ANNONATE:

BENEFITS OF THE PLASTER PARIS METHOD: -Sets after few minutes, mould taken out after an hour. -takes 24- 48 hrs to fully cure.

DISADVANTAGES : -Breaks easily its brittle -Cannot be used as very small pieces -gives monotonous ( lack of variety, dull ) look -High exothermic reaction burns skin

Its 3 part powder to 1 part water.

WAXING METHOD: 1.Washed thoroughly with normal saline. 2.Paraffin wax melted ( 55-60 oC ) using an incubator. 3.Glycerine applied on inner surface of wooden block.

So that when removing the mould it will be easy.

  1. Layer of waxed be 0.5cm thick.00

5.Takes 30-45 min to solidify at room temperature. 6. Then filled with ( 10% neutral buffered formalin ) -PRESERVATION FLUID!!

CONSTRUCTION OF PERSPEX MOUNTS:

-PERSPEX – Is a type of acrylic thermoplastic. - Available as clear or coloured sheet, rods & tubes commercially. - Excellent for construction of cases, shelves & supports. -Come in various thickness ( 2-12mm) - Have light transmission of 92%. - It is ideal for anatomy department. It can be cut, glued, shaped & polished.

PERSPEX PROPERTIES:-LIGHTWEIGHT - half the weight of glass. -BREAK RESISTANCE – WITHSTANDS MANY TIMES OF IMPACT FORCE. -WEATHER RESTANCE-HEAT RESISTANCE- Can withstand temperature of -34oC – 93oC . -COLOURFAST

MOUNTING FLUID:FUNCTION: -Prevent any deterioration (becoming worse) of the prepared specimen. -it must have good optical qualities so that all details of the specimen can be seen clearly. -To try & retain colours of the specimen.

COMPOSITION OF THE FLUID:-GYCERINE – 20% -DISTILLED WATER – 77% -FORMALIN – 3%

NB!! 🠶 When constructing your mounting containers, remember that a rebate joint will always produce a stronger containers because it provides a larger surface area for cementing thereby preventing leaking of mounting fluid.

EMBALMING:  Changes in the human body after death cannot be stopped by be slowed down by placing in -4 degrees Celsius.

POST MORTEM CHANGES IN THE HUMAN BODY:-AUTOLYSIS – Spontaneous decomposition of the body by means of enzymes.

-BACTERIAL DECOMPOSITION – Consumption of body tissues by live micro-organism, whereby bacteria multiply causing discolouration (green colour) abdomen

-RIGOR MORTIS – Temporary stiffness of muscles. -COAGULATION- Process of blood changing to form clots.

CAUSES OF DEATH THAT MAY INFLUENCE THE EFFICANCY OF THE EMBALMING PROCESS:1.ARTERIOSCLEROSIS – Chronic condition affecting the walls of arteries. 2.EMBOLISM – Obstruction of blood by means of clots or solid matter. 3.ARTHRITIS – Inflammation of the whole artery. 4.ANEURYSMS – Weakening , rupture or removal of artery walls.