2. Death - physical changes Flashcards Preview

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Flashcards in 2. Death - physical changes Deck (20)
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1
Q

In death and dying we look at 3 things

A
  1. what constitutes death
  2. immediate physical signs of death
  3. later changes in body
2
Q

2 stages of death are

A
  1. somatic death: organs stop working, person ceases to exist
  2. cellular death: death of individual tissues as oxygen supply runs out
3
Q

By definition death must be _________ and _________

A

permanent
irreversible

4
Q

True time of death is when the _______ is dead and it is called __________

A

brain
brain death

5
Q

Brain death characteristics (3)

A

person is deeply and irreversibly unconscious

he/she has lost ability to breathe and maintain heartbeat spontaneously

they have no prospect whatsoever of recovery

6
Q

Maintenance of breathing is controlled by the respiratory centre in the _________

A

brainstem

therefore, when brainstem stops working brain death becomes established

7
Q

Pre-conditions for brain death (3)

A
  1. must be deeply unconscious
  2. no spontaneous respiration
  3. no reversible metabolic condition, drug intoxication and no hypothermia
8
Q

Testing for brain death (5)

A
  1. pupils and corneal reflex unresponsive
  2. no vestibule-ocular reflex
  3. no motor response in CNs
  4. no gag reflex
  5. no respiratory effort with high CO2 trigger
9
Q

Brain death vs vegetative state

A

in brain death there is irreversible damage to vital centres in the brain, but rest of the brain may be functioning

in vegetative state brainstem is functioning but cerebral hemispheres are irreversibly damaged

10
Q

Immediate signs of death (4)

A
  1. no breathing (for 5min)
  2. no heartbeat (for 5min)
  3. pupils fixed and dilated
  4. body goes limp
11
Q

Later signs of death (4)

A
  1. heat loss (almost immediadetly)
  2. lividity/hypostasis (pooling of blood)
  3. rigor mortis
  4. decomposition (2-3 days)
12
Q

Describe heat loss curve

A
  • heat loss after death is not a steady drop
  • it starts slow
  • then it falls at a steady pace
  • then it slows down as it nears the room temp
  • sigmoid curve
13
Q

Variables affecting heat loss (6)

A
  1. surrounding temp
  2. clothing and coverings of the body
  3. body size
  4. body position
  5. initial temp
  6. cause of death
14
Q

Lividity/hypostasis characteristics (4)

A

after death blood in vessels sinks under gravity to lower parts of the body

it gives skin purple/pink colour, where the skin is pressed onto a surface it remains pale

if you die on back, lividity is on the back etc.

in CO poisoning it tends to be more pink than normal

15
Q

What is rigor mortis?

A

progressive stiffening and rigidity of the body from muscle contraction

it starts in small muscles, but eventually all muscles are affected (12h normally)

sped up by heat, slowed down by cold, remains until decomposition

16
Q

Which 2 molecules play a role in rigor mortis?

A

post mortem ATP converts to ADP

17
Q

What is decomposition?

A

Final stage of death, digestion by body’s own enzymes and bacteria

18
Q

2 processes of decomposition

A
  1. autolysis: chemical digestion by body’s own enzymes, immediately after death
  2. putrefaction: much more important, breakdown by bowel bacteria
19
Q

Time-scale for decomposition changes

A
  1. 2-3 days: green discolouration of lower abdomen
  2. 5-6 days: green and purple discolouration of whole trunk, blistering and marbling
  3. 7 days: swelling, fluid
  4. final stage: liquefaction until skeleton
20
Q

2 occasional variations of decomposition are

A
  1. mummification: skin becomes dry and leathery in warm, dry atmosphere
  2. adipocere: in damp conditions with little to no air (well), fatty tissues change to hard-soap like material, waxy