2. Death - physical changes

Question 1

In death and dying we look at 3 things

Answer 1

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

Question 2

2 stages of death are

Answer 2

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

Question 3

By definition death must be _________ and _________

Answer 3

permanent
irreversible

Question 4

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

Answer 4

brain
brain death

Question 5

Brain death characteristics (3)

Answer 5

person is deeply and irreversibly unconscious

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

they have no prospect whatsoever of recovery

Question 6

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

Answer 6

brainstem

therefore, when brainstem stops working brain death becomes established

Question 7

Pre-conditions for brain death (3)

Answer 7

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

Question 8

Testing for brain death (5)

Answer 8

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

Question 9

Brain death vs vegetative state

Answer 9

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

Question 10

Immediate signs of death (4)

Answer 10

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

Question 11

Later signs of death (4)

Answer 11

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

Question 12

Describe heat loss curve

Answer 12

• 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

Question 13

Variables affecting heat loss (6)

Answer 13

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

Question 14

Lividity/hypostasis characteristics (4)

Answer 14

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

Question 15

What is rigor mortis?

Answer 15

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

Question 16

Which 2 molecules play a role in rigor mortis?

Answer 16

post mortem ATP converts to ADP

Question 17

What is decomposition?

Answer 17

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

Question 18

2 processes of decomposition

Answer 18

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

Question 19

Time-scale for decomposition changes

Answer 19

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

Question 20

2 occasional variations of decomposition are

Answer 20

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