300816 Lecture Notes - Lecture 2: Atheroma, Hemoglobin, Metastasis
Document Summary
Condition in which the presence of abnormality of the body causes a loss of normal health. Abnormalities causing a disease can be both structural and functional. Normal is impossible to define, due to differences between individuals and changes in the human body (during puberty, pregnancy etc. Normality, when quantifiable, is expressed as a normal range usually encompassed by 2 standard deviations from the mean. Healthy mountaineers who ascend to rarefied atmosphere at high altitudes often develop mountain sickness" recover through adaptation such as increased haemoglobin. Ageing decreases the ability to deal with new or worsening environmental threats. Few diseases can have beneficial effects on the individual; they can confer adaptive protection against specific environmental pathogens. Susceptibility of a species to injurious environmental factors results in either its extinction or the favoured selection of a new strain of the species better adapted to withstand these factors. Aetiology is the cause of a disease. Pathogenesis is the mechanism causing the disease.
