PATH1001 Lecture Notes - Lecture 2: Wound Healing, Hyperlipidemia, Frostbite
Document Summary
Causes of cellular injury: most disease begin with cell injury, cellular injury occurs if cell cant maintain homeostasis when faced with injurious stimuli. Ie lack of 02 (hypoxia), chemical/physical/infectious agents, genetic factors and nutritional imbalance-all are noxious (cause harm) Extent of injury depends on: type and state of cell (dividing/matured, severity and duration of stimulus, modifying factors (nutritional status) Hypoxia-lack of adequate oxygen: most common cause of cellular injury is hypoxia. Conditions that cause lack of 02: disease of respiratory system (asthma, blockage of upper airways in the lungs, lower conc of 02 (increasing altitude) Insufficient transport causes: a decrease in haemoglobin, decreased production of rbc (decreased 02 carrying capacity, disease of cardiovascular system (heart pumping insufficient) Most common cause is ischaemia-restriction in blood flow caused by: narrowing of arteries (arteriosclerosis, complete blockage by blood clots (thrombosis) Physical agents: damage tissues by penetrating skin (surgical incisors, environmental stressors (high/low temp, atmostpheric pressure and sunlight)