Pathology Flashcards
forensic pathology
subfield that focuses on determining cause of death for persons who died suddenly, unexpectedly, or violently
external examination during autopsy
- inspection of external surface
- weight and measurement
- signs of decomposition
- associated objects
- note injuries, scars, and tattoos
opening the trunk during an autopsy
- opening up the midsection
- Y incision
- sternal plate removed
examination of internal organs in an autopsy
organs are removed, examined, weighted, and dissected
tissues during an autopsy
- sections of diseased or injured tissues and preserved for further studies
- specimens for toxicology testing
- DNA analysis
how are tissues preserved?
- fixed in formaldehyde
- encased in paraffin
- stained
- mounted on glass slide
specimens for toxicology testing
- urine
- blood
- bile
DNA analysis during autopsy
- blood
- hairs pulled from head
- non preserved tissue
removal of the brain during autopsy
- cut made ear to ear along the back of the head
- skin folded over and a stryker saw is used to cut through the cranial vault
final tasks of an autopsy
- return organs
- sew skin back in place
- wash
blunt force injury - bruise
- blood escapes from damaged vessels
- many factors affect degree of bruising
age of bruise
- hemoglobin -> biliverdin -> bilirubin
- blue / red -> purple -> green -> light green -> yellow
blunt force injuries
- sufficient force to overstretch the skin to the point of tearing
- most common in skin directly over bone
sharp force trauma - incised wound
- clean edges
- no bridges
- longer than deep
- lack of bruising
sharp force trauma - stab wound
- puncture wound
- deeper than wide
- some bruising
aging wounds
- injuries, day before death show signs of healing
- very hard to distinguish wounds created before, during, and after death
asphyxia
- cells don’t receive oxygen
- cells receive oxygen but cannot use it
- cells are unable to eliminate carbon dioxide
what affects the degree of brusing
- force of hit
- material hit with
- area of body hit
- medications
- blood disorders
- age
categories of asphyxia
- airway obstruction
- neck/ chest compression
- postural/ positional
- environmental
- poisoning
pathological features of asphyxiation
- cyanosis
- petechiae
cyanosis
- condition of being blue
- no oxygen makes hemoglobin darker
petechiae
- blood vessels bursting
- comes from pressure on veins or arteries
hanging
ligature furrows elevate to the back and side of the neck, behind the ears
strangulation
- ligature furrows lower, horizontal, completely encircles the neck
- back of the neck has trauma
how to determine if death was before or after a fire?
- soot in LUNGS (not just airways
- saturation level of carboxyhemoglobin > 10%
how does CO kill you?
- hemoglobin carries oxygen and carbon dioxide
- carbon monoxide binds very tightly to hemoglobin
- oxygen and carbon dioxide can no longer be carried
gun shot wounds: entrance vs exit wound
exit woulds are always larger than entrance wounds
contact range of shot
- muzzle imprint
- marrow ring of soot on skin
- ballooning / laceration of surrounding skin
intermediate range of shot
- wider zone of powder stippling
- lack laceration
- lack of muzzle imprint
distant range of shot
- lack stippling
- hole = caliber size
