This document defines and describes various types of asphyxia including mechanical asphyxia, anoxic anoxia, anemic anoxia, stagnant anoxia, histotoxic anoxia, hanging, strangulation, throttling, smothering, traumatic asphyxia from overlaying, choking, and drowning. It discusses the causes of death, post-mortem findings, and whether the asphyxia could be homicidal, suicidal, or accidental for each type.

1. ASPHYXIA

2. DefinitionIt isany condition thatleads to: - reduction of the oxygensupply to the blood and the tissues below the the normal physiologicallevel (hypoxia). - elevation of CO2 in the blood (hypercapnia).**Hypoxiameans (lowoxygen) whileanoxiameans (withoutoxygen).

3. Types of anoxia:(1) Anoxicanoxia: - Ambient. - Central. - Paralytic. - Mechanical (violent asphyxia). - Obstruction of the blood flow to the lungs.(2) Anemicanoxia: - Chemicallycombinedhemoglobin. - Hemolysis. - Hemorrhage.(3) Stagnant anoxia.(4) Histotoxicanoxia.

4. Stages of mechanicalanoxia or violent asphyxia:Three stages:(1) Stage of forced respiration: - It is due to stimulation of the respiratory center. - Clinicalpicture: DYSPNEA(2) Stage of convulsions: - It is due to cerebral irritation. - Clinicalpicture: CONVULSIONS, CYANOSIS, HYPERTENSION, LOSS OF CONSCIOUSNESS, CONSTRICTED PUPILS.(3) Stage of paralysis: - Clinicalpicture: LOSS OF CONSCIOUSNESS, FLACCID MUSCLES & LOST REFLEXES, DEEP CYANOSIS, DILATED PUPILS, IRREGULAR BREATHING (Cheyne-Stokes respiration). **Deathoccurs in about 5 minutes..

5. General postmortempicture of mechanicalanoxia: - Deepcyanosis. - Proptosis of the eyeballs. - Bloody frothfrom the nose and mouth. - Congested face withpetechialhemorrhage all over. - Dark violet or blue extensive hypostasis. ** All these are externalsignsN.B: Blood isdark and fluid in consistancy due to increased CO2 and fibrinolysisrespectively.

12. HangingDefinition:It is the mechanicalanoxicdeath due to suspensionof the body from the neck by a ligature.Causes of death: - Cerebralischemia. - Vagal cardiac inhibition. - Mechanicalanoxia. - Transection of the spinal cord (judicialhanging).

13. Post-mortem picture:(1) General(2) Specialfeatures - Protrusion of the tongue. - Dribbling of saliva. - Hypostasis of the lowerhalf of the body. - Neck signs: .Elongated and the headistilted 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

31. StrangulationDefinition: It is the mechanicalanoxicdeathcaused by constriction of the neck by a ligature occluding the air passages fromoutside.Causes of death: - Mechanicalanoxia. - Reflex cardiac inhibition. - Delayededema of the glottis and choking.

32. Postmortempicture of strangulation:(1) General(2) SpecialfeaturesAll 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 ligatingmaterial. - Inward fracture of the hyoidbone and the thyroid cartilage maybefractured. - Contusions and lacerations of the neck muscles.**Homicidal, suicidal or accidental

48. Throttling «Manual strangulation»Definition: It is the mechanicalanoxicdeathcaused by constriction of the neck by the hand occluding the air passages fromoutside.Causes of death: - Mechanicalanoxia. - Reflex cardiac inhibition. - Cerebralanoxia. - Delayedglotticedema and choking.

49. Postmortempicture:(1) General(2) Specialfeatures All are neck signs - Multiple contusions and fingernail abrasions. - Inward fracture of the hyoidbone (itis the mostcommon cause of hyoidbone fracture) and fracture of the thyroid cartilage. - Contusions of the deep tissues of the neck.** Homicidal, suicidal or accidental

53. SmotheringDefinition: It is the mechanicalanoxicdeathcaused by occlusion of the externalrespiratoryopenings by the hand or soft objects.Causes of death:MechanicalanoxiaPostmortempicture of smothering: (1) General (2) Specialfeatures - Multiple contusions and fingernail abrasions. - Contusions in the buccal mucosa. - Ventral hypostasis in cotdeath.** Homicidal, suicidal or accidental

59. Traumatic asphyxia: OverlayingDefinition: It is the mechanicalanoxicdeath due to mechanical pressure by a heavyobject on the chestwith or without abdominal compression leading to prevention of respiratorymovements.Causes of death: - Mechanicalanoxia. - Injury to vital organs.

60. Postmortempicture(1) General(2) Specialfeatures - Contusions and abrasions of the chest and abdomen. - Fracture ribs. - Rupture of internalorgans. - Line of demarcationbetween the discoloredupper part of the body and the lower part.** Homicidal, suicidal or accidental

62. ChokingDefinition: It is the mechanicalanoxicdeathcaused by occlusion of the respiratory passages frominside.Causes of death: - Reflex cardiac inhibition - MechanicalanoxiaTypes: - Pathological - Non-pathological**Homicidal, suicidal or accidental

67. DrowningDefinition: It is the mechanicalanoxicdeath due to submersion of the respiratoryopeningsunder water.Causes of death: - Direct causes: mechanicalanoxia - Indirect causes: . Reflex cardiac inhibition due to vagal stimulation . Head injury or other fatal injuries.

68. Posrmortempicture of drowning- Sure externalsigns: . Froth . Cadavericspasm- Probable externalsigns: . Related to anoxicanoxia: cyanosis . Related to presence of the body in water: skin is pale&wetGoose skinWasherwoman skinPostmortem injuries . Affection of postmortem changes due to presence in water:Cooling, hypostasis, adipocere, putrefaction**Homicidal, suicidal or accidental