300816 Lecture Notes - Lecture 4: Ricinus, Mercury Poisoning, Endoplasmic Reticulum
Document Summary
Drugs and poisons can cause direct injury through binding and destruction of cellular components. Mercuric chloride (mercury poisoning) increases permeability of the membrane and reduces atpase dependent transport. Infectious organisms deliver chemicals that may be toxic to the host"s metabolism or membrane integrity. Cause passive cell destruction by membrane disruption or functional impairment. Trauma and thermal injury cause cell death by disrupting cells and denaturing proteins. Freezing damages cells mechanically because their membranes are perforated by ice crystals (hypothermal injury). It lowers heart rate and increases blood viscosity. A hyperthermal injury leads to increased metabolic rate and increased oxygen demand. A localised heating burn coagulates proteins and disrupts tissues. At the translational level there is a constant requirement to replace enzymes and proteins, thus cell function is compromised is protein synthesis is blocked. Ricin, a potent toxin from the castor oil plant acts in this manner. Free radicals are atoms or groups of atoms with an unpaired electron.
