Strangulation

Strangulation is a form of asphyxia (lack of oxygen) characterized by closure of blood vessels or air passages of neck as result of external pressure on the neck

Rudimentary knowledge of neck anatomy is critical in order to understand adequately the clinical features of strangled victim

General clinical sequence of victim, who is being strangled, is one of severe pain followed by unconsciousness, which is followed by brain death

Victim loses consciousness by any one or all of the following: blocking of carotid arteries (depriving brain of oxygen); blocking of jugular veins (preventing deoxygenated blood from exiting brain); and, closing off airway, causing victim to be unable to breathe

Visible injuries to neck include scratches, abrasion and scrapes

Said injuries may be from victim's own fingernails as defensive manoeuvre, but the same commonly are combination of lesions caused by both victim's and assailant's fingernails

Lesion location varies depending on whether victim or assailant has used one or two hands, and whether the assailant has strangled the victim from the front or back

Three types of fingernail markings may occur, singly or in combination: impression; scratch; or claw marks

Chin abrasions are also common in victims of manual strangulation as victim lowers the chin in an instinctive effort to protect neck and in so doing , scrapes the chin against the assailant's hands.