Objective: (SAME AS YESTERDAY) SWBAT use the evidence of livor mortis, Objective: (SAME AS YESTERDAY) SWBAT use the evidence of livor mortis, rigor mortis, and algor mortis to calculate the approximate time of deathrigor mortis, and algor mortis to calculate the approximate time of death

Do Now:

1.Describe the causes of rigor mortis.

2.Define livor and algor mortis

3.How can these be used to calculate time of death?

Simple Terms

What? Why ? Factorsthat will affect it

Rigor

Livor

Algor

MortisMortis

Mortis refers to deathMortis refers to death

Rigor Mortis - stiffRigor Mortis - stiff Livor Mortis- blueish colorLivor Mortis- blueish color Algor Mortis- coldnessAlgor Mortis- coldness

Rigor MortisRigor Mortis

Rigor MortisRigor Mortis

Skeletal muscles partially contractSkeletal muscles partially contract Joints stiffen, lock in placeJoints stiffen, lock in place Beginning about 2 hours after deathBeginning about 2 hours after death Lasting about 30 hours Lasting about 30 hours

Simple Term(s)

What? Why ? Factorsthat will affect it

Rigor

Livor

Algor

Chemistry of Rigor Mortis Chemistry of Rigor Mortis

Calcium -> ATPCalcium -> ATP http://www.youtube.com/watch?v=C

epeYFvqmk4 1:401:40

End of rigor mortisEnd of rigor mortis

End of Rigor MortisEnd of Rigor Mortis

AutolysisAutolysis decompositiondecomposition digestive enzymesdigestive enzymes Rupture and release fluidsRupture and release fluids The muscles relax when the body The muscles relax when the body

starts to decompose and the cells starts to decompose and the cells begin to break downbegin to break down

RED LIGHT!!!!!RED LIGHT!!!!!

What causes rigor What causes rigor mortis?mortis?

STOP!Hold Up!Whoa There!Run That Back

Ca and ATP Ratchet the Ca and ATP Ratchet the FibersFibers

30-1530-15

30 seconds to explain30 seconds to explain 15 seconds to ask questions15 seconds to ask questions Switch Switch

Why is this useful Why is this useful

TimeTime PositionPosition LocationLocation

Livor MortisLivor Mortis

Heart stops beating which had been Heart stops beating which had been mixing bloodmixing blood

Red blood cells are denser so they sinkRed blood cells are denser so they sink Maroon to blue color develops at Maroon to blue color develops at

lowest pointslowest points Visible 30 minutes 12 hours after Visible 30 minutes 12 hours after

deathdeath Tells you if the body was moved.Tells you if the body was moved.

Livor MortisLivor Mortis

Pressure prevents poolingPressure prevents pooling

Livor MortisLivor Mortis

Livor MortisLivor Mortis

After death cells release enzyme that After death cells release enzyme that preventsprevents clotting clotting

Blood in body stays liquid after deathBlood in body stays liquid after death

Algor MortisAlgor Mortis

Rate of cooling of body after deathRate of cooling of body after death– 1.5 1.5 °°F per hour under “normal conditions”F per hour under “normal conditions”

0.78 Degrees Celsius 0.78 Degrees Celsius

Algor MortisAlgor Mortis

Clothing Clothing – Insulates body from heat lossInsulates body from heat loss

ObesityObesity– Fat insulates, temperature falls more Fat insulates, temperature falls more

slowlyslowly Ratio of surface area to volumeRatio of surface area to volume

– Children, thin people cool fasterChildren, thin people cool faster In water?In water?

– Cooling is faster since water is a better Cooling is faster since water is a better conductor of heat than airconductor of heat than air

A man is found on the side of the A man is found on the side of the road. His body temperature is 32° C. road. His body temperature is 32° C. How long has this man been dead?How long has this man been dead?

A woman is found dead. Her body A woman is found dead. Her body temperature is 25° C. How long has temperature is 25° C. How long has this woman been dead?this woman been dead?

Exit TicketExit Ticket

Be specificBe specific

1.1. How can rigor mortis be used to calculate How can rigor mortis be used to calculate death?death?

How can algor mortis be used to calculate How can algor mortis be used to calculate death?death?

How can livor mortis be used to calculate How can livor mortis be used to calculate death?death?

Show your workShow your work

2. How long has a victim been dead, if she was 2. How long has a victim been dead, if she was found with a body temperature of 24 degrees found with a body temperature of 24 degrees Celsius? (R. more)Celsius? (R. more)