Stages of Mortis

Stages of
Mortis

In this lesson, we will be looking at ways in which our bodies decay after death. There will be pictures of deceased people.

Death is one of the most fundamental facts of life. It occurs in all organisms and is inevitable. There are 4 stages or changes that occur in the body after death. These are used as indicators to determine the cause, time, etc. especially in forensic pathology.

Definition: The body begins to cool down after death.

Timing + Use: This happens immediately and helps estimate time of death by body temperature.

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Algor Mortis

What things may impact the speed a body cools down?

Definition: The body becomes stiff as the muscles lock in place.

Timing + Use: Starts 2–6 hours after death and can show how long the person has been dead.

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Rigor Mortis

Definition: The body becomes pale due to lack of blood flow.

Timing + Use: Happens within 15–30 minutes after death and can help confirm that death was recent.

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Pallor Mortis

Definition: Blood pools in the lowest parts of the body, causing purple marks.

Timing: Usually sets in 20-30 minutes after death and becomes fixed at about 12 hours. After 12 hours, skin is no longer blanchable (white when pressure is applied).

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Livor Mortis

Livor Mortis

Used to determine body position at death and if body was moved
Different colours can mean different things and can sometimes help to determine cause of death, e.g. hypothermia, carbon monoxide poisoning, and cyanide intoxication. Carbon monoxide poisoning produces a cherry red stain instead of a usual dark purple.

Timeline of Death

Multiple Choice

What causes pallor mortis?

• Freezing of facial muscles

• Cooling of the body

• Blood circulation stopping

• Bacteria decomposing the body

Multiple Choice

How soon after death does pallor mortis appear?

• 15-30 minutes

• Immediately

• 30-60 minutes

• 2-6 hours

Multiple Choice

Is algor mortis an accurate way to determine time of death?

• Yes

• No

Categorize

Options (6)

Windy environment

Small body size

Being in cold water

Heavy clothing

Obesity

Warm indoor temperature

Drag the factors into the correct category:

Speeds up cooling

Slows down cooling

Multiple Choice

What is the normal temperature of our bodies?

• 36.1 degrees Celsius

• 35 degrees Celsius

• 38 degrees Celsius

• 37 degrees Celsius

Multiple Choice

What causes rigor mortis?

• Blood settling in the body

• The body cooling down

• ATP energy in the muscles running out

• Nerve signals being overloaded as the brain dies

Multiple Choice

When does rigor mortis typically begin?

• Immediately after death

• 1–2 hours after death

• 6–12 hours after death

• After 24 hours

Reorder

In what order does rigor mortis usually appear?

• Face

• Torso

• Limbs

1

2

3

• 1
• 2
• 3

Multiple Choice

After 36–48 hours, rigor mortis disappears as the body starts decomposing.

• True

• False

Multiple Choice

If lividity is fixed, what does this mean?

• Blood is still moving

• The body has no stiffness

• The blood has settled and won't shift if the body is moved

• The time of death cannot be determined

Multiple Choice

How may this person have died?

• Ceiling fan fell on them while they were sleeping

• Stuck in a washing machine after it's been turned on

• Bungee jump cord that couldn't be pulled back up

• Went head first down a water slide and ran into the person in front of them