• Is the closure of the air passages as a result of external pressure of the neck which prevents the ingress or regress of air during respiration.

Symptoms of asphyxia

  • Asphyxia is manifested by symptoms divided into 3 stages
    • Dyspnoea
    • Convulsions
    • Exhaustion
  • Dyspnoea: caused by the accumulation of carbondioxide in the blood due to deficient oxygenation of the RBC’s carbondioxide stimulates the respiratory centre in the medulla and respiration becomes deep, hurried and laboured. The blood pressure rises and pulse become rapid. Animal bears an anxious look, eyes prominent and Lips are livid.
  • Convulsions: Expiratory muscles of respiration become more active with spasmodic movements which are followed by convulsions of all the muscles of the body. Owing to venous and capillary stagnation, the m.m are deeply congested and cyanosed. Tongue is protruding consciousness is lost. The sphincters are relaxed.
  • Exhaustion: It is the 3 stage. Respiratory centre is paralysed. Muscles become flaccid, completely insensibly, reflexes are lost, pupils are widely dilated.
    • Blood pressure ↓ falls
    • Respirations – prolonged sighing occur, at longer and longer interrals until they cease altogether and death ensues.
    • Pulse is scarcely perceptible. Heart beat continue for some minutes after respiration has ceased.

Post Morterm appearance

  • External
    • Mucous membrane 
    • Tongue - Protruded
    • Frothy and blood stained mucus at nostrils and from mouth
    • Rigor mortis – commences slowly but may be rapid in some cases
  • Internal
    • Mucous membrane of the Trachea and Larynx - Cinnabar red and slight frothy mucus
    • Lungs
      • Dark and purple in colour
      • Gorged with dark venous blood
      • On being cut, lung exlude frothy, dark fluid blood.
      • Air sacs are distended or ruptured due to emphysema
    • Heart - Right cavity of the heart filled with dark – coloured imperfectly clotted blood and so in the pulmonary artery and the vena cava.
      • Heart – The left side cavity, aorta and the pulmonary veins are empty.
      • In many cases, both sides of the heart are found to be full, if examined soon after death but after rigor mortis has sent in, the heart is found contracted and empty. The tension in the abdomen presses on the inferior vena cava and drives the blood up into the heart.
      • Similarly, the lungs are found heavier with blood if examined sometime after death, or the tension in the abdomen or contraction of the heart muscle will drive more blood into the lungs, irrespective of the cause of death.
    • Brain – is congested and excess of serous fluid is found in the lateral ventricles. Cranial sinuses are filled with dark – coloured blood.
    • Abdominal organs are found congested.
    • Petechial haemorrhages or ecchymoses are seen under serous membranes of various organs due to rupture of capillaries caused by increased pressure. Petechial haemorrhages are observed under visceral pleume, pericardium, thymus meninges of the brain and spinal cord, conjunctiva, epiglottis and under skin of the face and neck.
Last modified: Tuesday, 5 June 2012, 10:01 AM