THE PHYSIOLOGY OF DEATH
MECHANISMS OF DEATH:
Organs are interdependent for their function. Failure of one organ may cause other organs to fail.
BRAIN ↔ LUNG ↔ HEART ↔ CIRCULATION ↔ KIDNEY ↔ LIVER
1 in 3 people die of Heart Attack. 1 in 5 dies of Cancer. The Brain houses the Respiratory centre which generates breath impulse and maintains Blood Pressure. The Heart pumps blood to the Lungs and the Brain, failing which breathing will not be possible or brain will not function and circulation will stop.
The Circulation holds blood volume and overload causes pulmonary (air sac) oedema and under load causes dehydration and blood deprivation to brain and heart. The circulatory system of arteries, veins and capillaries hold 5 litres of blood. Under load of blood causes dehydration and blood deprivation to brain, heart and lungs. Pulmonary oedema (internal drowning by water collection in air sacs) and failure of breathing.
Liver failure and kidney failure causes circulatory overload and pulmonary oedema (air sac drowning). Hardened Arteries due to ageing cause blocks and blood clots to form in arteries supplying heart resulting in death of heart chamber walls (called Heart attack or Myocardial infarction) or death of brain part (called Stroke or Brain attack) causing paralysis of one half of the body both of which may cause death.
Age causes blockages in the arteries supplying blood to the heart and the brain. Abrupt and complete block of the heart arteries cause death of a chamber wall (heart attack) and fall in its pumping capacity (heart failure) and death.
Abrupt and complete block of the brain arteries cause death of a portion of the brain, causing muscular paralysis (stroke). If, this extends to cause death of the stem, the breath impulse generation fails resulting in death.
Loss of blood supply can also occur if blood pressure falls due to bleeding, dehydration or heart failure. Acute fall in blood pressure can cause death.
Cancer can cause death not by itself but by unrelated Heart attacks.
Duration of death:
The process of death involves causing multiple organ failure to stop life. Death can come after different durations
(a) Sudden –Death in a few hours
(b) Acute – pre death disease for a few days
(c) Sub acute – pre death disease for a few weeks
(d) Chronic –pre death disease for a few months