1. ASPHYXIA

2. Definition
 It is any condition that leads to:
- reduction of the oxygen supply to the
blood and the tissues below the the normal
physiological level (hypoxia).
- elevation of CO2 in the blood
(hypercapnia).
**Hypoxia means (low oxygen) while anoxia
means (without oxygen).

3. Types of anoxia:
) Anoxic anoxia:1(
) Anemic anoxia:2(
) Stagnant anoxia.3(-
) Histotoxic anoxia.4(

4. Stages of mechanical anoxia or violent
asphyxia:
Three stages:
 (1) Stage of forced respiration:
- It is due to stimulation of the respiratory center.
- Clinical picture: DYSPNEA
 (2) Stage of convulsions:
- It is due to cerebral irritation.
- Clinical picture: CONVULSIONS, CYANOSIS,
HYPERTENSION, LOSS OF CONSCIOUSNESS, CONSTRICTED
PUPILS.
 (3) Stage of paralysis:
- Clinical picture: LOSS OF CONSCIOUSNESS, FLACCID
MUSCLES & LOST REFLEXES, DEEP CYANOSIS, DILATED
PUPILS, IRREGULAR BREATHING (Cheyne-Stokes
respiration).

5. General signs
- Deep cyanosis.
- Proptosis of the eye balls.
- froth from the nose and mouth.
- Dark violet or blue extensive
hypostasis.

6.  BLOOD =fluidity increased due to
(fibrinolysin _ co2 _ ca+2 ,p change )
 Spots (tardieu spots ,silver spots )
 All organ congested
 N.B: Blood is dark and fluid in consistancy
due to increased CO2 and fibrinolysis
respectively.

8. Drowning
 Definition:
It is the mechanical anoxic death due to submersion
of the respiratory openings under water.
 Causes of death:
- Direct causes: mechanical anoxia
- Indirect causes:
. Reflex cardiac inhibition due to vagal stimulation
. Head injury or other fatal injuries.

9. Posrmortem picture of drowning
 - Sure external signs:
. Froth
. Cadaveric spasm
 - Probable external signs:
. Related to anoxic anoxia: cyanosis
. Related to presence of the body in water:
skin is pale&wet
Goose skin
Washerwoman skin
Postmortem injuries
. Affection of postmortem changes due to presence in water:
Cooling, hypostasis, adipocere, putrefaction
**Homicidal, suicidal or accidental

10. ASPHYXIAL CONDITIONS-DEFINITIONS
Drowning is the
process of
experiencing
respiratory
impairment from
submersion/immersi
on in liquid.

12. Hanging
 Definition:
It is the mechanical anoxic death due to
suspension of the body from the neck by a
ligature.
 Causes of death:
- Cerebral ischemia.
- Vagal cardiac inhibition.
- Mechanical anoxia.
- Transection of the spinal cord (judicial
hanging).

13. Post-mortem picture:
 (1) General
 (2) Special features
- Protrusion of the tongue.
- Dribbling of saliva.
- Hypostasis of the lower half of the body.
- Neck signs:
.Elongated and the head is tilted to the opposite
side of suspension point.
.Ligature marks (HIGH UP in the neck, OBLIQUE,
INCOMPLETE, has an IMPRINT of the ligature).
** Homicidal, suicidal or accidental

14. Types of hanging
Point of comparison COMPLETE HANGING INCOMPLETE HANGING
Other name High point hanging Low point hanging
Touching the ground Negative Positive
Circumstances Presence of a near-by table
or chair
Negative
Main cause of death Cerebral ischemia Asphyxia
Face Less congested, sometimes
pale
Markedly congested
Hypostasis Lower half of the body According to the part
touching the ground
Type of knot Fixed knot or running noose Always running noose
Rope marks -Incomplete with fixed knot
-Above thyroid cartilage
-Oblique
-Deep and fades gradually
towards suspension point
-Complete
-Below thyroid cartilage
-Transverse
-Deep all through
Dribbling of saliva Positive Negative
Tear in carotid intima Positive Negative
Hyoid bone If fractured: outwards If fractured: inwards

32. Strangulation
 Definition:
It is the mechanical anoxic death caused by
constriction of the neck by a ligature
occluding the air passages from outside.
 Causes of death:
- Mechanical anoxia.
- Reflex cardiac inhibition.
- Delayed edema of the glottis and choking.

33. Postmortem picture of strangulation:
 (1) General
 (2) Special features
All are neck signs:
- Ligature marks:
. Low in the neck below the thyroid cartilage.
. Transverse.
. Complete.
. Deep all through.
. Abrasions and contusions taking the shape of the ligating
material.
- Inward fracture of the hyoid bone and the thyroid cartilage
may be fractured.
- Contusions and lacerations of the neck muscles.
**Homicidal, suicidal or accidental

49. Throttling
«Manual strangulation»
 Definition:
It is the mechanical anoxic death caused by
constriction of the neck by the hand occluding the
air passages from outside.
 Causes of death:
- Mechanical anoxia.
- Reflex cardiac inhibition.
- Cerebral anoxia.
- Delayed glottic edema and choking.

50. Postmortem picture:
 (1) General
 (2) Special features
All are neck signs
- Multiple contusions and fingernail abrasions.
- Inward fracture of the hyoid bone (it is the most
common cause of hyoid bone fracture) and fracture
of the thyroid cartilage.
- Contusions of the deep tissues of the neck.
** Homicidal, suicidal or accidental

54. Smothering
 Definition:
It is the mechanical anoxic death caused by occlusion of
the external respiratory openings by the hand or soft
objects.
 Causes of death:
Mechanical anoxia
 Postmortem picture of smothering:
(1) General
(2) Special features
- Multiple contusions and fingernail abrasions.
- Contusions in the buccal mucosa.
- Ventral hypostasis in cot death.
 ** Homicidal, suicidal or accidental

60. Overlaying results from compression of the
chest, nose and mouth, so as to prevent
breathing.

61. Traumatic asphyxia:
Overlaying
 Definition:
It is the mechanical anoxic death due to
mechanical pressure by a heavy object on
the chest with or without abdominal
compression leading to prevention of
respiratory movements.
 Causes of death:
- Mechanical anoxia.
- Injury to vital organs.

62. Postmortem picture
 (1) General
 (2) Special features
- Contusions and abrasions of the chest and
abdomen.
- Fracture ribs.
- Rupture of internal organs.
- Line of demarcation between the discolored
upper part of the body and the lower part.
 ** Homicidal, suicidal or accidental

64. Burking is a
combination of
homicidal
smothering and
traumatic asphyxia.

65. Choking
 Definition:
It is the mechanical anoxic death caused by occlusion of
the respiratory passages from inside.
 Causes of death:
- Reflex cardiac inhibition
- Mechanical anoxia
 Types:
- Pathological
- Non-pathological
 **Homicidal, suicidal or accidental