DNA forensics

Question 1

What are the Post-mortem Changes?

Answer 1

Pallor Mortis (Paleness)
Livor Mortis (Bluish color)
Algor Mortis (Coldness)
Rigor Mortis (Stiffness)
Eye changes.
Putrefaction
Mummification

Question 2

Pallor mortis(30 min)

Answer 2

Pallor mortis results from the collapse of capillarycirculation throughout the body.
-The first stage of death, is an after-death paleness that occurs in those with light/white skin.
-Occurs almost immediately, generally within 15–25 minutes after death.
-No use in determining the time of death, aside from saying that it happened less than 30 minutes ago.

Question 3

Livor mortis(fixed after 8 hours)

Answer 3

Hypostasis is the second stage of death.

-After Pallor Mortis, gravitythen causes the blood to sink down into the lower parts of the body except the independent part.

-starts in 20–30 minutes, but it is usually not observable by the human eye until 2 hours after death in independent parts of the dead body.
-It can be fixed in its place after 8 hours.

Question 4

Medicolegal of hypostasis

Answer 4

1.Sure sign of death.
2.Rough estimation of time of death.
3.Detection if the position of the body has been changed after death or not.
4.Identification of possible cause of death through color and site.

Question 5

Algor Mortis (after 18–24hours)

Answer 5

1- The third stage of death, is the post-mortem gradual decrease in body temperature, until it equalizes the temperature of the surrounding environment.
2- is the result of a cessation inthermoregulation. As body temperature is controlled by thehypothalamus

Question 6

Factors affecting Algor Mortis (Body Cooling)

Answer 6

1-Body temperature.
2-Body weight: The rate of cooling will be slower in an obese body.
3-Temperature of the environmental surroundings: The rate of cooling will increase in a body immersed in water, a naked body, and a thin body( elder and babies).
4-Clothes worn by cadaver: If the body is wearing clothes

Question 7

Rigor Mortis (Appears after 2 hours)

Answer 7

-is the fourth stage of death, resulting in the stiffening of the body muscles due to chemical changes in their myofibrils.

-helps in estimating the time since death as well to ascertain if the body had been moved after death.

• (disappears after 12-36 hours)

Question 8

Primary flaccidity( lasts between 2-6 hours)

Answer 8

-General relaxation of the entire muscular system immediately after death, lasts between 2-6 hours.
-Starts before rigor mortis
-There is respond to electrical & mechanical stimuli

Question 9

Secondary flaccidity (occurs 18-24 hours after death )

Answer 9

1- Complete relaxation of the body muscles, occurs 18-24 hours after death
2- Follows rigor mortis
3- No respond to electrical & mechanical stimuli.

Question 10

What is Cadaveric spasm?

Answer 10

1- is a rare form of muscular stiffening that occurs at the moment of deathand persists into the period of rigor mortis.
2- stronger stiffening of the muscles than rigor mortis.
3- It is neurogenic in nature and means the death occurred in intense physical and/or emotional activity.

Question 11

Eyes changes

Answer 11

1-The clear glistening appearance of the cornea is lost, the cornea appears dry, cloudy and opaque.
2-The light reflex is lost.
3-The intraocular tension falls and the eye balls become flaccid and sink into the orbit.
4-The blood stream in the retinal vessels becomes segmented.
5-Taches noire (3 hr after death)

Question 12

Mummification

Answer 12

is a modification of the putrefaction process, characterized by the dehydration of the cadaveric tissues.

Question 13

Asphyxia

Answer 13

can be defined as the condition of deficient supply of oxygento the body, which arises from abnormal breathing.

Question 14

What are the main kinds of asphyxia?

Answer 14

1-Mechanical asphyxia
2-Traumatic asphyxia
3-Perinatal (birth) asphyxia
4-Compressive (compression) asphyxia

Question 15

1-Mechanical asphyxia

Answer 15

when an object or a physical force stops you from breathing. It also includes body positions

Question 16

2-Traumatic asphyxia

Answer 16

caused due to mechanical fixation of the chest so that normal movements of chest wall are prevented.
-occurs when a large weight falls onto or presses down on an individual’s chest.

Question 17

3-Perinatal (birth) asphyxia.

Answer 17

Birth asphyxia is when your baby doesn’t get enough oxygen right before, during or right after birth.

Question 18

4-Compressive (compression) asphyxia

Answer 18

is a type of mechanical asphyxiation. A strong external force presses on your chest or abdomen. Examples include a large crowd pushing against your body

Question 19

– Mechanical asphyxia types:

Answer 19

Smothering, hanging, throttling, strangulation, chocking, drowning and traumatic asphyxia

Question 20

Causes of asphyxia

Answer 20

1. Mechanical asphyxia
2. Poisoning
3. Pathological:

Question 21

Poisoning

Answer 21

• Morphine, barbiturate causing central asphyxia.
• Strychnine causing peripheral asphyxia.
• Carbon monoxide CO.
  -Cyanide.

Question 22

Autopsy findings in asphyxia:
A) Externally:

Answer 22

-The face is congested, swollen with petechiae.
-Eyes appear prominent, congested, dilated pupils, and subconjunctival petechiae.
-Lips finger nails are deeply cyanosed.
-Froth from mouth and nostrils (may be bloody)
-Tongue is protruded, sometimes bitten
- Semen may be ejaculated.
-Hypostasis is dark.
-Evidence of the cause: nail abrasion on face

Question 23

Autopsy findings in asphyxia:
B) Internally:

Answer 23

Blood is dark and more fluid.
-Internal organs are deeply congested.
Evidence of the cause:
-Bruises in subcutaneous tissue of the face, Neck,
fracture of hyoid bone or laryngeal cartilage, foreign body in air passages.

Question 24

1-Hanging

Answer 24

Constriction of neck anatomical structure by ligature using weight of the body

Question 25

2- Strangulation

Answer 25

asphyxia by closure of the blood vessels and/or air passages in the neck due to external pressure by rope

Question 26

Ligature strangulation:

Answer 26

is a violent form of death, which results from constricting the neck by means of a rope

Question 27

Throttling

Answer 27

When constriction is produced by the pressure of the fingers and palms upon the throat.

Question 28

Mugging

Answer 28

When strangulation is brought about by compressing the throat with a foot, knee, bend of elbow, or some other solid substances.

Question 29

Smothering

Answer 29

Homicidal smothering is the deliberate occlusion of the external airways, usually using the hands, pillows, or bedding

Question 30

Gagging

Answer 30

mechanical obstruction of oral cavity. It is usually resorted to prevent the victim from shouting for help. -Later the gag becomes progressively soaked with saliva and/or mucous.

Question 31

Choking

Answer 31

It is a form of asphyxia caused by an obstruction within the air passage by a foreign body

Question 32

Drowning

Answer 32

defined as a process of respiratory impairment from submersion in a liquid medium.

Question 33

Drowning is categorized into 4 principal types:

Answer 33

1- Wet Drowning 2- Dry drowning 3- Secondary drowning 4- Immersion syndrome

Question 34

Cuticle

Answer 34

Its scales, How many there are per centimeter, How much they overlap, Their overall shape, and How much they protrude from the surface Its thickness, and Whether or not it contains pigment

Question 35

The cortex varies in:

Answer 35

Thickness Texture Color

Question 36

Medulla

Answer 36

The medulla may vary in: Thickness Continuity - one continuous structure or broken into pieces Opacity - how much light is able to pass through it

Question 37

The Life Cycle of Hair

Answer 37

1- anagen stage, hair actively grows. 2-In the catagen stage, the hair grows and changes. 3- telogen stage

Question 38

Hair type

Answer 38

Scalp hair Pubic hairs Beard hairs Eyebrow hairs