1. ‫بسم ا الرحمن الرحيم‬

7. yaseen.muhammad50@face
book.com
definition
conditions
stages
causes
mechanism
classification
pm findings/ext/internal

8. Definition:
• Conditions in which the supply of oxygen to the
blood and tissues has been reduced below the
normal working level by any interference with
respiration.
• Asphyxia is used as being equal to “lack of
oxygen” or “hypoxia”,

9. Definition
Any condition that
obstruct respiratory passages or
interferes with respiratory process
resulting in a lowered O2 (hypoxia)
and increased CO2 (Hypercapnia).

10. Mechanical Asphyxia
ASPHYXIA
• Interference with oxygenation – any where from
environment down to cellular level

11. Mechanical Asphyxia
CAUSE S OF ASPHYXIA:
 Environmental
 Obstruction of external respiratory passages
 Obstruction of internal respiratory passages
 Restriction of respiratory movements
 Lung disease
 Deficient oxygen transport

12. Mechanical Asphyxia
MECHANISMS
 Environmental
 Low or no atmospheric oxygen e.g. ships holds
 Scuba diving, surgical anesthesia, disused
refrigerators
 Suffocation
 Smothering
 Gagging
 Choking

13. Mechanical Asphyxia
 Throttling
 Ligature Strangulation
 Hanging
 Traumatic asphyxia
 Sexual asphyxia
 Positional asphyxia

15. Mechanical Asphyxia
SUFFOCATION
 Obstruction of mouth and nose
 Smothering / overlaying / plastic bags
TRAUMATIC
 Pressure fixation of chest wall & abdomen — burying
under debris / vehicle / crowd pressure- stampede/
knee abdomen pressure / scissor technique / prone
position /overlaying / anaconda large snakes

19. Mechanical Asphyxia
STRANGULATION
 Obstruction of air way at the level of larynx by a
ligature directly applied on the neck
HANGING
 Compression of the neck structures by means of
ligature-the pressure applied through suspension
of body

20. Mechanical Asphyxia
MECHANISM OF DEATH
 Oxygen deprivation
 Carbon dioxide accumulation
 Reduced blood flow to and from the brain
 Vagal stimulation resulting in cardiac inhibition
 Complex

21. Mechanical Asphyxia
PATHOLOGICAL CHANGES
• General
▫ Cyanosis
▫ Congestion
▫ Engorgement right side heart
▫ Fluidity of blood
▫ Petechial hemorrhages / Tardieus spots

30. Classify Mechanical Asphyxia;
what are specific pathological changes
in mech asph,
give one point in favour for each type
PATHOLOGICAL CHANGES
• Specific
Evidence of asphyxiating mechanism
Bruising of lips / nose(smothering)
Finger nail marks on the neck (throttling)
Ligature mark on the neck (ligature strangulation)
Signs of trauma to chest ( traumatic asph.)
Specific – Injuries to the largynx (structures)

31. Mechanical Asphyxia
PATHOLOGICAL CHANGES
• Specific – Injuries to the larynx
▫ Hyoid bone
▫ Thyroid cartilages
▫ Cricoid cartilage
▫ Carotid artery
▫ Vagus nerve

32. Mechanical Asphyxia
Sexual / Autoerotic Asphyxia / Autoerotic
Deaths

Accidental hangings, failure of safety mechanisms

Male, trasvestism or nudity, masochism,
pornographic material

Scene is diagnostic.

33. Mechanical Asphyxia
POSITIONAL ASPHYXIA
 Bodily position which obstructs airway or
impairs act of breathing
 Typically associated with sedative
intoxication
 Usually accidental (alcoholics)

34. Mechanical Asphyxia
• Environmental asphyxia
▫ Due to lack of oxygen in the environment

35. Mechanical Asphyxia
SUFFOCATION
 Obstruction of nose and mouth
 Homicidal, soft smothering
 "Overlaying"
 Plastic bags, suicidal or accidental
Difficult diagnosis; history and scene.

38. Mechanical Asphyxia
CHOKING

Obstruction of upper airway or glottis

Gag, homicide, rarely suicide

Accidental in elderly, mental defectives, children

"Cafe Coronary"

39. Mechanical Asphyxia / Throttling
THROTTLING (Manual Strangulation)
Form of mechanical asphyxia where neck structures
are compressed by hand / hands
 Different grips, different patterns
 Finger pad bruises, crescent abrasions
 Neck muscle haemorrhages - thyroid cartilage
fractures
 Mugging, bansdola / sleeper hold
 Grip for half a minute.

40. Mechanical Asphyxia / Throttling

General signs of asphyxia
 Congestion of face / bleeding from mouth and nose

Evidence of asphyxiating mechanism
 Multiple bruises on the neck / finger nail marks, bruises may not
be obvious if throttling affected through soft material
 Bruising of neck muscles
 Rupture of intima carotid artery
 Fracture of thyroid cartilage one or both superior horns.
 # Hyoid bone is rare because of lower position of grip

45. Mechanical Asphyxia / Strangulation
STRANGULATION
 Air way obstruction at larynx from pressure by a
ligature / garrotting

Horizontal groove, uniform depth, imprint abrasion,
ligature groove may be multiple / knotted

Tied, held, removed – sexual assault

46. Mechanical Asphyxia / Strangulation
 Bruises, abrasions
 Neck muscle haemorrhages, thyroid cartilage
fractures
 Suicide uncommon but possible – tourniquet /
accident occasional – children playing / babies
falling from cot / female pelion rider – dupatta /
burqa entangling in the wheel / chain

47. Mechanical Asphyxia / Strangulation
MECHANISM OF HYOID BONE FRACTURE
• Direct compression
• Indirect – pull on the thyro hyoid ligament

57. Asphyxia or asphyxiation
• (from Greek α- "without" and sphyxis,
"heartbeat") is a condition of severely deficient
supply of oxygen to the body that arises from
being unable to breathe normally
• Asphyxia causes generalized hypoxia, which
primarily affects the tissues and organs.
• There are many circumstances that can ;induce
asphyxia

58. Asphyxia can cause coma or death
 the constriction or obstruction of airways, such as
from asthma, laryngospasm, Respiratory diseases




or simple
blockage from the presence of foreign
materials;
from being in environments where oxygen is not readily
accessible: Exposure to extreme low pressure
such as underwater, in a low oxygen atmosphere, or in a
vacuum;
environments where sufficiently oxygenated air is present, but
cannot be adequately breathed because of air contamination
such as excessive smoke..

59. Other causes of oxygen deficiency
include
Carbon monoxide inhalation, such as from a car
exhaust:
carbon monoxide has a higher affinity than oxygen
to the hemoglobin in the blood's red blood
corpuscles, bonding with it tenaciously,
 Contact with certain chemicals, including
pulmonary agents (such as phosgene) and blood
agents (such as hydrogen cyanide)
 Drug overdose
 Sleep apnea

60. •
•
•
•
•
Ondine's curse,
central alveolar hypoventilation syndrome
Acute respiratory distress syndrome.
Hanging
Drowning

61. Ondine's curse
 , also called congenital central
hypoventilation syndrome (CCHS) or
primary alveolar hypoventilation, is a
respiratory disorder that is fatal if untreated.
Persons afflicted with Ondine's curse classically
suffer from respiratory arrest during sleep.
 CCHS is congenital or
 developed due to severe neurological trauma to
the brainstem

62. Stages of asphyxia
1- Stage of dyspnea:
. 2- Stage of convulsions:
. 3-Stage of apnea
(respiratory paralysis
The respiratory center (RC) is
located in the medulla
oblongata, which is the lowermost
part of the brain stem
The groups of nerve cells in the brain
which regulates the respiration rhythmically
are collectively known as respiratory
centers

63. Respiratory centre is divided four
major groups
• Inspiratory centre (Dorsal respiratory
group)
• Location: Dorsal portion of medulla
• Nucleus: Nucleus tractus solitarius
• Function: causes inspiration while stimulated.

64. Expiratory centre (Ventral respiratory
group)
 Location: Antero- lateral part of medulla, about
5 mm anterior and lateral to dorsal respiratory
group
 Nucleus: Nucleus ambiguous and nucleus retro
ambiguous.
 Function: It generally causes expiration but can
causes either expiration or inspiration
depending upon which neuron in the group are
stimulated. It sends inhibitory impulse to the
apneustic centre.

65. Pneumotaxic centre








Location: Pons(upper part )
Nucleus: Nucleus parabrachialis
Function: It controls both rate and pattern of breathing.
Limit inspiration.
Apneustic centre
Location: Pons(lower part)
Function:
a)It discharges stimulatory impulse to the inspiratory centre
causing inspiration.
b)It receives inhibitory impulse from pneumotaxic centre
and from stretch receptor of lung.
c)It discharges inhibitory impulse to expiratory centre.

66. Respiratory center depression
• Depression of a respiratory center can be a result
of next reasons:
• medical drug action (opioids, sedatives and etc.)
• sudden cessation of blood circulation in brain
• heavy brain trauma
• sharp neuroinfections
• brain tumors
• damage of a brainstem

67. A convulsion is a medical condition where body muscles contract and relax
]
.rapidly and repeatedly, resulting in an uncontrolled shaking of the body
The pattern repeats, with each cycle usually taking 30 seconds to 2 minutes. It is
an oscillation ( periodic variation )of ventilation between apnea and hyperpnoea

78. General Post Mortem Appearance
External Appearances:.Face: oedematous and congested.
.Eye: proptosis due to retro-orbital oedema.
.Deep cyanosis: especially in nails and lips.
.Lividity appears early and is well formed.
hial hemorrhages: in the skin and eyes
articularly the eyelids, conjunctiva, sclera, face,
ps and behind the ears).

81. Petechial Hemorrhage
Sites of formation:
in the skin and eyes
, particularly the eyelids, conjunctiva, sclera, face
)
lips and behind the ears
• A petechial hemorrhage is a tiny pinpoint red
mark that is an important sign of asphyxia
caused by some external means of obstructing
the airways. They are sometimes also called
petechiae. Their presence often indicates a death
by manual strangulation, hanging, or
smothering.

83. Mechanism of formation
• The hemorrhages occur when blood leaks from
the tiny capillaries in the eyes, which can rupture
due to increased pressure on the veins when the
airways are obstructed.
• If petechial hemorrhages and facial congestion
are present, it is a strong indication of asphyxia
by strangulation as the cause of death.

84. External Postmortem (PM) picture
1- Petechial hemorrhages
3- Cyanosis
2- Postmortem hypostasis is well-developed
and dark in color
4- Rigor mortis is rapid
5- Putrefaction is rapid.

86. Internal Appearances:.Visceral congestion.
.Petechial hemorrhages: in the visceral pleurae
and pericardium are often known as "Tardieu's
spots". Tardieu's spots ; spots of ecchymosis
under the pleura after death
Dark::Blood. due to the large amount of
reduced hemoglobin.
Fluid:- release of fibrinolysin shortly after
death.

87. Internal Postmortem (PM) picture
• Petechial hemorrhages under the pleura and
pericardium and in the internal organs.
Congestion and edema of the viscera
• The blood is dark in color and more
fluidly.
• The right heart and great veins are engorged
with blood.

89. Classification of asphyxia
1-Mechanical Asphyxia
2-Toxic Asphyxia
pertaining to force and matter, as
distinguished from mental, vital, chemical,
.etc
3-Pathological Asphyxia
4-Neonatal Asphyxia
ectrical Asphyxia-5
phyxia Due To Low Atmospheric Oxygen Conten

90. MECHANICAL ASPHYXIA;













A-Hanging
B-Strangulation; Throttling ;(it is a manual strng)
Mugging
Ligature
Bansdola ;a form of strangulation where the neck is
compressed in between two bamboo or other sticks, one
in front and the other behind
Garroting A garrote (a Spanish word; is a weapon,
referring to a handheld ligature of chain, rope, scarf, wire
used to strangle a person
Suffocation'sSmothering
Choking
Gagging
drowning
Traumatic asphyxia -D

91. •HANGING ;It is violent form of Asphyxial
death caused by suspension of the body by a
ligature around the neck, the constricting
force being the weight of the body.
Lynching; is a condition where several persons acting jointly
overpower an individual &hang him by rope
Strangulation
• It is a form of violent asphyxia
• caused by constricting the neck by some mean
,other than wt of body
throttling
,mugging
,bansdola
Garroting
.are types of strang
...

92. suffocation
 ;smothering ;obstruction to air passages from
outside)nose ,mouth by hand or cloth
 Choking
Obststruction from inside by solid object( foreign body)
results reflex spasm , death is due to vagal inhibition or
laryngeal spasm
Drowning
It is a form of violent asphyxia in which death results
from submersion of mouth and nostrils of a living
person under water
traumatic asphyxia or crush asphyxia is usually used to describe
compressive asphyxia resulting from being crushed or pinned under
a large weight or force

93. Violent Asphyxial Deaths
1- Hanging It is Asphyxial death caused by
suspension of the body by a ligature around the
neck, the constricting force being the weight of
the body.
2- Ligature strangulation A violent Asphyxial
death caused by constricting the neck by a
ligature
3- Manual strangulation (Throttling)
4- Smothering:
5- Choking
6- Traumatic asphyxia (Crush asphyxia)

94. .Hanging:- suspension of the body by the use of a ligature. It
resembles Ligature strangulation except for the fact that in hanging the
constriction Force
being the weight of the body and the force of gravity as well.

99. 1- Hanging
 It is Asphyxial death caused by suspension of the body by a
ligature around the neck, the constricting force being the weight
of the body.
A) It may be either complete or partial:
on the basis of degree of suspension
B) It may be either typical or atypical:
on the basis of position of knot
Complete ; when wt of the body acts as constricting force
Incomplete; when part of the body act as constricting force
Typical; Knot at the occipit
Atypical; Knot at any site other than the occipit

102. Types of knot
Running noose
Fixed knot

103. Complete hanging

106. Incomplete hanging

110. That form of asphyxial death,
caused
by suspension of body by a ligature round the
neck, constricting force is wt of the body.
.
hanging
Cause of death
1-asphyxia due to blocking of air passages, by
ligature.
 2-cerebral congestion due to compression of
jugular veins(congestive hypoxia)
3 -pressure on carotid arteries, obstruction of
arterial blood, thus cerebral anoxia &coma.
4-vagal shock from compression of trigger area.
5 -injury to spinal cord as in judicial hanging.

111. Mechanical Asphyxia / Hanging
Mechanism of Death in Hanging
• Asphyxia – anoxic hypoxia
• Reflex cardiac arrest
• Cerebral anoxia
• Cerebral congestion
• Fracture dislocation cervical vertebrae

112. Mechanical Asphyxia / Hanging
AUTOPSY FINDINGS
• Body partly / completely suspended by ligature around the
neck
• Brown leathery ligature furrow, imprint abrasion
• Fixed noose-inverted v-shape, knot mark
• Running noose – horizontal

113. Mechanical Asphyxia / Hanging
• Low suspension point – groove less marked,
lower, horizontal
• Typically no classical asphyxial features
• Scene shows preparation and precautions

114. Mechanical Asphyxia / Hanging
INTERNAL SIGNS:
 Bruising – occasionally rupture of neck muscles –
sternomastoid
 Bleeding between pharynx and spine
 Injury to carotid arteries with bleeding in the walls
or horizontal breech of the intima at the level of
ligature

115. Mechanical Asphyxia / Hanging
 Fracture of Hyoid bone – greater cornu at junction
of outer third with inner two thirds esp. after age
40
 Fracture thyroid cartilage – great horn/s
 Fractures of Hyoid and thyroid may occur alone or
together – may not occur in low suspensions

121. Mechanical Asphyxia / Hanging
JUDICIAL HANGING
 Body given a drop of 2 – 4 feet, the noose tightening
and cervical spine receiving a jerk – dislocation and
fracture at 3rd and 4th or 2nd and 3rd cervical vertebrae
severing the upper part of spinal cord – instantaneous
death , heart may continue to beat for a few minutes

122. Mechanical Asphyxia / Hanging
• Incomplete Suspension
▫ Body not completely suspended – continuous
pressure of ligature causes asphyxia

128. 







Death is instantaneous usualy but,5-8 minutes
is common fatal period.
Pm appearances;
ext-dribbling of saliva due to stimulation of
salivary glands by ligature is a vital sign,
indicating that victim was alive at the time of
suspension.
Ligature mark on the neck;
in complete hanging mark is situated over the
level of thyroid cartilage b/w larynx&chin.seen
in front, sides of neck.
Lig knot may form a fixed or running noose
Internal appearance;
local injury ,spinal cord inj

129. Ml aspects;









1-wether death was due to hanging;
ligature mark is usually found,
2-lig mark e pet hmrge,
dribble saliva, carotid art tear,
absence of fatal inj &poisoning.
Suicidal hang;
it is common in men,
there is no signs of struggle,
farewell note will be present.

130. Is it suicidal, homicidal, or accidental
hanging?
Suicidal: (most common):
• Circumstantial evidence (history of failure).
• Absence of signs of struggle.
• Presence of signs of previous suicidal attempts.
• Suicidal note

131. Homicidal hanging;
 is suspected ,when knot is tied in the back of
neck,
 mouth is gagged ,
 limbs are tied,
 injuries on body,
 signs of struggle are present.
 Lynching; is a condition where several persons
acting jointly overpower an individual &hang
him by rope.
 Sexual asph (auto erotic hanging) also described.

132. Externally:
• The neck is stretched.
• The face is pale or bluish.
• The rest of the body is cyanosed.
• Saliva may be seen dripping from the mouth
(It is a vital sign and is present only in hanging but
not in postmortem suspension).

133. Ligature mark:
• Shape:
It is a depression at the site of the ligature
• Situation:
Transverse and complete
(if running noose).
• The pattern of the ligature:
Is imprinted on the neck as a pressure
abrasion.

135. Ligature mark:
• Shape: as in hanging.
• Situation: At the level of thyroid cartilage or
below.
• Transverse and
• complete (this is the usual).

139. Mechanical Asphyxia / Hanging
 Almost all hangings are suicidal
 Sudden compression of the neck blocks the blood
vessels disrupting blood supply to and from the brain
 Usual point of suspension is the side of the neck
(typical hanging) followed by back and front (atypical
hanging)

140. Strangulation
It is a form of violent asphyxia
 caused by constricting the neck by some means
 other than wt of body.
The means used may be
;ligature,
 hand((throttling) ,
elbow(mugging)or
 stick(bansdola)
Strangulation should be assumed to be homicidal,
until contrary is proved
Mugging; strangulation by compression neck again
forearm
garroting; strng by grasping the throat , throwing a
over neck.
Throttling ;it is a manual strng

141. .Strangulation

142. 2- Ligature strangulation
 A violent Asphyxial death caused by constricting
the neck by a ligature.
 Mechanism of death:
 Asphyxia: from compression of air passage
 Cerebral congestion or apoplexy:
 Reflex vagal inhibition
 Cerebral anoxia:
 Combination of any of the above

151. 3- Manual strangulation (Throttling)
• caused by constricting the neck by the hand.
• Autopsy appearances:
• Externally:
• Injuries on the neck:
• Abrasions (caused by finger nails).
• Contusions (caused by finger pads).

152. .Throttling:- constriction of the neck by the use of hands.

157.  Suffocation; this is a form of asph
 ,caused by mechanical obstruction of air
passages,by means other than constriction of neck
 It includes ;
 smothering (obstruction to air passages from
outside)nose ,mouth by hand or cloth.
 Choking
 ;obstr from inside by solid object( foreign body)
results reflex spasm , death is due to vag inhibition
or laryngeal spasm.
 Drowning; submersion of mouth&nostrils under
water
 Traumatic asph;obst to resp movements

160. Autopsy appearances:
• Externally:
• The face is either pale or bluish and congested.
The rest of the body is cyanosed.
• The tongue may be protruded, swollen and
bitten.
• Bleeding from ears and nose may be seen.

162. 4- Smothering:
 Caused by mechanical occlusion of the air
passages from outside (i.e. the mouth and
nostril) by hand or by any object.
 PM picture
 Asphyxial signs will be present except in case of
plastic bag suffocation.
 Abrasions and contusions on the skin of the face
around mouth and nose
(Absent if a soft material, such as a pillow, is used).

163. Smothering :
Is blockage of external air passages by (fabric, sheet, solid
material)
Groups of risk are elderly , infants
A part from classical signs of asphyxia such as petechiea
may appear and there is usually a lack of objective
finding.
Plastic bag suffocation can be rapid and symptomless
depending on how it is done.
The death in plastic bag facial occlusion is some rapid
cardio inhibitory mode rather than purely hypoxic
process.

164. .Smothering:-occlusion of external respiratory openings

165. 5- Choking
• Caused by mechanical occlusion of the air
passage from inside.
Mechanism of death:
Asphyxia: due to either complete occlusion of air
passage, or
partial occlusion that is completed by spasm,
edema and mucus secretion.

166. . Choking:- Obstruction to the air passage due to foreign
body impaction.

168. Accidental: (most common)
May arise from:
• Inhalation of irritant fumes.
• Impaction of foreign material, such as food or
denture.
• Inhalation of dust and sand in falling of houses.
• Inhalation of vomit or blood during operations.
• Falling back of the tongue epileptic fit.

170. Choking
Refer to the blockage of the internal air
way( glottis or trachea) by foreign bodies .
Almost Accidental
Death can be of purely hypoxic origin from
occlusion of airway with characteristic signs of
congestion , cyanosis & petechiae.
The groups most at risk are :
Children, old people, mentally disorder, drunk,Greedy
Eaters ,Drugged

171. Café coronary
This is a condition of accidental choking
where a bolus of food produces complete
obstruction of larynx .it is so called b.c it
mimics heart attack .it may be d/t
Suppressed gag reflex – alcoholics, drug
intoxicated
Reflex cardiac arrest; due to stimulation of
laryngeal nerve
The victim who was healthy apparantly
collapses & suddenly turns blue while eating

177. Mechanical Asphyxia
Medicolegal Aspects
 Mode of death – asphyxia / anoxia / cerebral
congestion / vagal inhibition / fracture dislocation
cervical vertebrae
 Cause of death – suffocation / throttling /
strangulation / hanging / drowning
 Manner of death – suicidal / homicidal /
accidental

178. Mechanical Asphyxia / Manner of
Death

Suffocation – accidental / homicidal – plastic bags

Gagging – homicidal

Throttling – homicidal

Strangulation – homicidal – accidental esp. children

179. Mechanical Asphyxia / Manner of
Death
 Hanging – almost always suicidal – accidental
 Suspension of body after death to simulate suicidal
hanging – circumstances / scene / locus examination
 Evidence of other cause of death
 Sexual asphyxias – accidental

181. What is a "cafe coronary?
• "Cafe coronary" is poorly named because it has
nothing to do with a heart attack. This condition
got its name because onlookers may think they
are witnessing a heart attack when a diner is
really choking to death. "Cafe coronary" is
blockage in the upper airway, usually caused by
food or vomit stuck in the throat. The blockage
causes choking and makes it hard to breathe. It
can be life threatening.

182. Choking (Cafe Coronary)
• How does choking occur?
• Choking occurs when a piece of food or some
other object gets stuck in the airway. Chicken,
fish bones, and pieces of meat that have not been
chewed properly get stuck in the throat easily. If
you have been drinking alcohol, your risk of
choking is greater because you may be careless
about chewing food well.

183. What are the symptoms?
• Symptoms of choking may include:
• trouble talking or inability to talk
• high-pitched breathing, wheezing, or not
breathing at all
• forceful coughing or inability to cough
• clutching the throat or chest as a sign of distress
• fainting.

184. How does choking occur?
• Choking occurs when a piece of food or some
other object gets stuck in the airway. Chicken,
fish bones, and pieces of meat that have not been
chewed properly get stuck in the throat easily. If
you have been drinking alcohol, your risk of
choking is greater because you may be careless
about chewing food well.

185. What are the symptoms?
• Symptoms of choking may include:
• trouble talking or inability to talk
• high-pitched breathing, wheezing, or not
breathing at all
• forceful coughing or inability to cough
• clutching the throat or chest as a sign of distress
• fainting.

186. What are the symptoms?
• Symptoms of choking may include:
• trouble talking or inability to talk
• high-pitched breathing, wheezing, or not
breathing at all
• forceful coughing or inability to cough
• clutching the throat or chest as a sign of distress
• fainting.

187. Choking (Cafe Coronary)
• How can I help someone who is choking?
• If someone is choking but still able to breathe
and cough and is not turning a bluish color, let them
try to cough up the object. If they are having trouble
breathing and turning blue, have someone call while
you do the following to help:
• Ask the person if they are choking. If they cannot
answer you, or they grab their throat, they need help
right away.
• Give 5 back blows.
▫ Stand behind the person and wrap one arm around their
chest.

191. Crush asphyxia
traumatic asphyxia or crush asphyxia is
usually used to describe compressive asphyxia
resulting from being crushed or pinned under a
large weight or force
Ex..
collapsing trenches,
panic in crowds,
 car-jack while repairing from below, even
anacondas(monstor snake) and pythons(ajdaha)
 These case tend to exhibit gross congestion,cyanosis,and
petechiae of the face, neck and shoulder with bleeding
from the ear and the nose

196. Pressure on the chest and abdomen
due to:
• Burial in earth following house collapse.
• Crushing by a crowd, as in case of a fire.

197. Drowning:-This is due to submersion of the respiratory openings under.
.water or any other fluids

204. It is a form of violent asphyxia in which death results
from submersion of mouth and nostrils of a living person
under water
• Classification (types) of drowning:
1- Typical (wet) drowning:
2- Dry drowning.
3- Secondary drowning (Near-drowning).

205. Drowning is...
• Death secondary to asphyxia
while immersed in a liquid,
usually water, or within 24 hours
of submersion

206. In drowning...
air hunger and usually panic
Reflex inspiratory efforts lead to aspiration of
water and laryngospasm
asphyxia and hypoxaemia / acidosis

207. Asphyxia
Laryngospasm maintained
Relaxation of the airway
Respiratory arrest
Water enters lungs
Cardiac arrest
Surfactant washout
“Dry drowning”
“Wet drowning”
mechanism in fresh and salt water slightly*
different

208. 2- Sure external signs:
A-Froth:
(Fine – White – Odorless _ increase)
B-Cadaveric spasm
of the hands on weeds, mud, sand, etc.

210. Immersion is suffocatioin of mouth
&nostrils in liquid
• goose-skin, or anserina cutis, which is
roughening, or pimpling of the skin,
skin maceration, or washer-woman's skin, which
is swelling and wrinkling of the skin, and
adipocere, which is the transformation of the
fatty layer beneath the skin into a soap-like
material - a process requiring many weeks or
months

212. External appearances
1. Signs of immersion:
These are found in any body found dead in water
(whatever the cause of death).
• Coolness of the body.
• Goose-skin the skin is wrinkled.
• Washerwoman-skin: the skin is sodden.
• Peeling of the epidermis in the form of gloves
and stockings.
• Hypostasis

213. Goose skin

214. Goose

215. Washerwoman’s hands

217. Internal appearances
• Voluminous lungs with indentation marks of
ribs on their lateral surfaces.
• Respiratory passages contain froth (having the
same characters of that found externally at the
mouth and nostrils),

218. Diatoms: microscopic, unicellular algae, found
• These are
in fresh as well as salt water.
• When a live person is drowned in water, they
penetrate his alveolar membrane and pass with
the circulation to distant organs.
• But when a dead body is thrown into water, the
absence of beating heart prevents circulation of
diatoms to distant organs.

219. The medico-legal (ML) importance of diatoms:
• 1- Sure signs of drowning,
• 2- Could still be identified in putrefied bodies,
• 3- Could give an evidence of the site of drowning
(fresh or salt water species).

220. In putrefied bodies:
• Only diatoms could be identified

224. 2-Toxic Asphyxia
.Due to intoxication with poisons such as:
.Cyanide.
.Carbon monoxide.
.Organic Phosphate fertilizers.

225. 3-Pathological Asphyxia
Pulmonary Embolism.
Glottic Oedema.
Acute Pulmonary Oedema.

226. 4-Neonatal Asphyxia
Hypoxic hypoxia due to distorted umbilical cord
or uterus spasm.

227. Asphyxia is Asphyxia
5-Electrical due to
• Convulsions and spasm of respiratory muscles.
•Central due to depression of respiratory
center.

228. 6-Asphyxia Due To Low Atmospheric
Ambient Anoxic Anoxia.
Oxygen Content
Specially in:
•high altitudes
•Presence of CO2 or N2