The Pathology of Trauma

Dr A Tay

The Anatomy Lesson of Dr. Tulp by Rembrandt

Abrasion

• An abrasion is a superficial injury, commonly known as a 'graze' or 'scratch'.'glancing' impact

'crush' injury

Abrasions

• Patterned abrasions

Lacerations

'gashes, tears or cuts' of the skin. The skin surface is split or torn following blunt trauma, and the force causes the full thickness of the skin to be damaged. Lacerations therefore bleed profusely.

• Incised wound

Incised wounds• Incised wounds are sharp cut-like injuries, made by knives or

broken glass etc.

• Slash Wounds These are wounds where the length is greater than the depth, eg a

slice wound across the skin. If the wound involves major blood vessels, it can be life threatening, but in general, they are not as serious as stab wounds

• Stab Wounds These are wounds where the depth of injury is greater than the

length. They penetrate more deeply than slash wounds and tend to come into contact with vital organs in the chest and abdomen.

Stabbing is the most common mode of homicide in the UK, due to the strict control of guns.

• Stab wound

• Defence wounds

• Stab wound with hilt

mark

Bruises• Bruises are caused by blunt trauma / injury to tissues, resulting in

damage to blood vessels beneath the surface. Blood leaks out ('extravasation') into surrounding tissues from damaged capillaries, venules and arterioles. Bruises may be surface bruises, or deeper within tissues or organs.

• characteristics of the object causing a bruise cannot easily be determined

• ecchymoses - smaller than a few milimeters

• petechiae - pinpoint bruises. (However, this type of bruise or haemorrhage are usually due to venous engorgement, for example in asphyxia, or in defects in blood coagulation such as Disseminated Intravascular Coagulation (DIC) than trauma). Light trauma may produce petechial haemorrhage, but those caused by venous congestion etc are more diffuse in nature.

Scalp contusions

Asphyxia

• Asphyxia can literally be translated from the Greek as meaning 'absence of pulse', but is usually the term given to deaths due to 'anoxia' or 'hypoxia'.

• Categorising asphyxial deaths: Neck Compression Chest Compression

Postural/ Positional Asphyxia Airway Obstruction Exhaustion or Displacement of Environmental Oxygen

Asphyxia

Classic signs of asphyxia • congestion of the face - due to venous congestion

(venous return to the heart is prevented)

• facial oedema - increased venous pressure causes tissue fluid transudation (Starling forces)

• cyanosis - excess de-oxygenated haemoglobin in the venous blood

• petechial haemorrhages in the skin and eyes (particularly the eyelids, conjunctiva, sclera, face, lips and behind the ears) - due to raised venous pressure 

Petechial hemorrhages

Gunshot wounds

• Types of firearms

• Distance

• Entrance

wound

• Exit

wound

Rembrandt – The Nightwatch