6. Learning From The Dead Flashcards
(50 cards)
Forensic pathology
> The study of injuries and or diseases to determine the cause of death
- A post-mortem investigation of sudden or unexpected death or trauma to the living
- Speacilisit knowledge of injuries and diseases to determine cause of death
- Conduct autopsis
Role of forensic pathologist
- Confirm death has occurred
- Estimate time since death
- Ensure positive identification
- Record injuries and natural disease if any
- Determine the cause of death
- Form an opinion on possible manner of death through reconstruction of events
5 possible Manner of death
Natural • Accidental • Homicide • Suicide • undetermined
What is an autopsy
• Inspect body internally or externally
—> Autopsy (necropsy and post-mortem examinations are synonymous) means to ‘see for oneself’.
• It is an opportunity to directly inspect and analyse the organs.
2 types of autopsy
- The clinical or academic autopsy:
* The medico-legal or forensic autopsy:
• The clinical or academic autopsy:
○ The medical attendants, with the consent of relatives, seek to learn the extent of the disease for which they were treating the deceased patient.
○ Study disease and treatment given to patient
• The medico-legal or forensic autopsy:
○ Performed on the instructions of the legal authority responsible for the investigation of sudden, suspicious, unnatural or criminal deaths.
○ Legal requirement e.g. when attending can’t determine cause of death
○ Consent is not required for this
Physical evidence
—> Before an autopsy can occur, a medical examiner will search for any physical evidence on the body
- Weight
- Height
- Fingerprints
- Physical distinguishing charactersitics
- Physical evidence e.g. bite marks
- Biological evidence – insect or qounds
- Chemical evidence – alcohol or drugs
- Physioloigcal evidence – bone, hair, blood
Rigor mortis
—-> Stiffening of body because of lack of oxygen in muscle cells.
• Begins around 4 hours after death.
• Begins in eyelids and small muscles of jaw, then to neck and rest of body.
• Sits in more quickly when there has been a violent struggle (uses up energy in muscles)
• Completely sits in within 12 hours after death and lasts around 36 hours before body returns to non-rigid state
Impacted by temperature and environment
Rigor mortis - time period
Less than 3 hours – warm 3 - 6 hours – warm but stiff 6 hours – cool but stiff 36 hours – cold and no stiffness • Use to determine cause of death
Liver mortis
–> Discoloration of skin after death = blue to purple areas
• Caused by gravity-induced stagnation and settling of red blood cells in small blood vessels.
• Commonly referred to as “lividity
• Occurs 6-8 hours after death.
• Occurs in parts of body closest to ground by effect of gravity
Types of wounds
- Lacerations - irregular tearing of tissue that is contaminated wit bacteria
- Incised wounds – not deep but caused by sharp items
- Puncture wounds- sharp pointed object
- Abrasions - rubbing of skin
- Contusions – rupture of small vessels
- Gunshot wounds – determine type of firearms distance of shooter
Steps of an autopsy
Rigor mortis and liver mortis • Internal and external • Opening of trunk: • Y incision • Open rib cage • Remove organs • Specimens for testing – fixed with formaldehyde • Brain stored in 10% formaldehyde for 2 weeks • closing
Purpose of an autopsy
• find Difference between antimortem and post mortem body
Why examine dead bodies
To:
– Understand the anatomy of the body
– Correlate structure to function
– study the effects of disease processes and cause of death
Assess the effect of therapeutic interventions
• Find evidence for criminal proceedings
4 Common affected areas of sudden death
- Head ‘
- Heart
- Blood vessels
- Lungs
Head - sudden causes of death
Extradural haemorrhage
Subdural haemorrhage
Sub arachnoid haemorrhage
Intracerebral haemorrhage
Intracranial aneurysm
Meninges - structure and definition
Meninges – membranous covering of connective tissue that support brain and spinal cord • Made of 3 layers ○ Periosteal dura mater ○ Meningeal dura mater ○ Arachnoid mater
Extradural haemorrhage
– collection of blood between the skull out outer layer of the dura (periosteal dura).
○ Occurs due to head trauma and can lead to sudden death
Subdural heamorrhage
– collection of blood in the subdural space due to bleeding from vein in the area – connection of blood between arachnoid dura layer and meningeal dura mater
○ Occurs due to head trauma and can lead to sudden death
○ This can increase pressure on underlying brain tissue
Sub arachnoid haemmorhage
– collection of blood in sub arachnoid space
○ Associated with rupture of aneurysm due to dilation or weakness of blood vessel
○ Pressure and compression on brain tissue
○ Related to trauma, infection, neoplasma
Intracerebral haemoorhage
- haemorrhage within brain tissue
○ Space occupying tissue, causes compression and pressure on brain, affecting function
Intracranial aneurysm
– weakness in the wall
○ Trauma or hypertension leads to rupture and death
Stroke
—> clinical manifestation of blockage or disruption to brain tissue
