Welcome to the beginning of the second module, all about paleopathology. Paleopathology is a favorite topic of osteoarchaeology students and professors alike. In fact, I teach an entire course just on this topic. So in this module, we clearly cannot cover all of the topics within paleopathology. Rather we have chosen three interesting case studies about trauma, infection and a vitamin deficiency. And shortly, we'll provide you with an introduction to bone biology that focuses on the way that the skeleton can respond to injury and disease. Let's begin with the definition. The term paleopathology was first coined by Sir Alfred Rucker in 1910, to mean the science of diseases whose existence can be demonstrated from human and animal remains from ancient times. Within this module, we'll be focusing solely on human examples. So, we look for the mark left on a bone or a tooth as a result of injury or disease, which we call a lesion. For example, on this left femur, your upper leg bone, you can see a rather large lesion here, just below mid-shaft. The subjects covered within the field of paleopathology can be categorized as follows. First, we have acquired conditions, so conditions obtained during life. These consists of trauma, infectious disease, joint disease, metabolic conditions, neoplastic conditions like cancer and dental disease. And then second we have congenital conditions. These exist at birth or just after, and refer to anomalies, malformations or diseases, which are either hereditary or acquired during gestation. Paleopathology provides evidence for the appearance and evolution of diseases. Because most of the skeletons we study come from the period before modern medicine. So before things like germ theory, vaccinations, antibiotics and chemotherapy. We can assess how a disease would progress in the absence of the medical treatment. We can also see the manifestation of a disease across the entire skeleton, including lesions not usually detectable with medical scans like x-ray or CT and not typically looked for by clinicians or pathologists. In regards to the importance of paleopathology for understanding past populations, we can make comparisons of the prevalence of a lesion or a disease in different geographic groups or between different time periods to try and say something about the health of a population. And this brings us to a really important point. And I'll explain why I used air quotes when using the term health. How do we define health? Even practitioners working with living people, with the whole body, have struggled to come up with a wholly satisfactory definition for health. There is an online forum discussion about this if you want to know more. So, it is perhaps easier to define the opposite of health, that is illness, injury, or abnormal condition and quite simply, an abnormal condition impairs bodily functions in some way. Thus health can be thought of as the absence of impaired function. But researchers have increasingly come to realize that we're never completely healthy. That is free from any and all impairment. Particularly when considering not only your physical health, but also your mental health. And it's for this reason largely that it's useful to think of health and disease as occurring on a continuum of more or less, not either or, and that the state of one bodily system may differ from the state of another within the same person. Before moving on to the next video, a few final definitions to ensure we're all on the same page. You'll often hear us talk about morbidity and mortality. Mortality, you probably know, means death. Morbidity, however, is different. And it means sickness, ill health, the disease state. It's the condition before death that you may survive. Finally, osteoarchaeologists work with prevalence data. With prevalence, meaning the total number of cases of a disease or injury within a population or the sample we're analyzing, over the entire time period during which they were buried. And this is different from the term incidence. Incidence is what modern health researchers usually use and refers to the number of new cases or new individuals who contract the particular condition during a specific period of time. In archaeology, we typically don't have good enough time resolution to study incidence. We've quickly introduced you to the field of paleopathology, and familiarized you with some of the terms needed before diving into the upcoming video, which explains how our bones respond to injury and disease. Stick with us, learn how the appearance and distribution of pathological lesions can be an incredible source of information about the ways of life. And in this case sometimes the ways of death of past peoples. For instance, do you know what disease caused the bowing deformity seen on this tibia? This is one of the bones from your lower leg. Well stick with us, and by the time this module is over you will know the cause of this deformity.
