Intrinsic Factors Definition And Example....
This word designates the ageing process. Familiar as we are with the general appearance of the changes produced by ageing, we as yet know practically nothing about the reasons for the inevitability of ageing, why it should happen at different rates in different individuals, or most important why it should occur prematurely in some.
Metabolism. Sometimes the chemical processes occurring in some or all cells take a wrong pathway and result in the formation of a new substance or more usually in the accumulation of one present normally in very small concentration which has a toxic effect on the cells. The accumulation of lactic acid in exercising muscle is an example that can be readily cured by resting the muscle; however, in gout the accumulation of uric acid in soft tissues around joints is not so easily corrected.
Nutrition. In order to survive, cells must receive the raw materials for their metabolism, and their waste-products must be removed. Disturbances affecting blood supply or respiratory gas exchange in general are important and may threaten life . Localized disturbances may also occur, due to obstruction of the local blood vessels supplying or draining the area.
Neoplasia. This word literally means new growth. It is synonymous with the layman's term 'cancer'. The essential characteristic of neoplasia is that certain cells grow in an inappropriate and disorderly fashion. It is important to recognize that even in a fully grown adult almost every cell in the body is growing by dividing into two new cells (the exceptions are the cells of the central nervous system). This process is essential because cells are also dying. In health there must be mechanisms (although we know practically nothing about them) that balance the rate of growth against the rate of destruction. In neoplasia, certain cells escape from the restriction of these mechanisms and grow unchecked. The extent of this escape can vary within very wide limits. Often the new growth (tumour) increases in size only for a limited period and then remains static. Such tumours are called benign, because they hardly disturb the rest of the body.
At the other extreme are fast-growing tumours which spread inexorably either by local continuity or by discontinuous spread to a distance (metastasis) in the bloodstream, the lymphatics, or across body cavities like the peritoneum, and finally kill the patient by the interference that the widespread deposits of tumour (metastases) exert on the vital functions of such organs as liver, lungs or brain.
Malignant tumours are subdivided into: (a) carcinomas derived from the skin lining the external surface of the body or the mucous membranes lining the digestive, respiratory and urogenital tracts and their related glands; and (6) sarcomas, derived from the connective tissues such as bone, muscle, cartilage, fascia, etc.
Auto-immunity. This phenomenon is described with immunity.
Advances in the last 100 years have gone fati-ocards solving the problems posed by external physical and biological agents that cause injury. The problems of degeneration and neoplasia, and to a less extent the errors of metabolism, now dominate the thoughts and efforts of medical scientists.
This word designates the ageing process. Familiar as we are with the general appearance of the changes produced by ageing, we as yet know practically nothing about the reasons for the inevitability of ageing, why it should happen at different rates in different individuals, or most important why it should occur prematurely in some.
Metabolism. Sometimes the chemical processes occurring in some or all cells take a wrong pathway and result in the formation of a new substance or more usually in the accumulation of one present normally in very small concentration which has a toxic effect on the cells. The accumulation of lactic acid in exercising muscle is an example that can be readily cured by resting the muscle; however, in gout the accumulation of uric acid in soft tissues around joints is not so easily corrected.
Nutrition. In order to survive, cells must receive the raw materials for their metabolism, and their waste-products must be removed. Disturbances affecting blood supply or respiratory gas exchange in general are important and may threaten life . Localized disturbances may also occur, due to obstruction of the local blood vessels supplying or draining the area.
Neoplasia. This word literally means new growth. It is synonymous with the layman's term 'cancer'. The essential characteristic of neoplasia is that certain cells grow in an inappropriate and disorderly fashion. It is important to recognize that even in a fully grown adult almost every cell in the body is growing by dividing into two new cells (the exceptions are the cells of the central nervous system). This process is essential because cells are also dying. In health there must be mechanisms (although we know practically nothing about them) that balance the rate of growth against the rate of destruction. In neoplasia, certain cells escape from the restriction of these mechanisms and grow unchecked. The extent of this escape can vary within very wide limits. Often the new growth (tumour) increases in size only for a limited period and then remains static. Such tumours are called benign, because they hardly disturb the rest of the body.
At the other extreme are fast-growing tumours which spread inexorably either by local continuity or by discontinuous spread to a distance (metastasis) in the bloodstream, the lymphatics, or across body cavities like the peritoneum, and finally kill the patient by the interference that the widespread deposits of tumour (metastases) exert on the vital functions of such organs as liver, lungs or brain.
Malignant tumours are subdivided into: (a) carcinomas derived from the skin lining the external surface of the body or the mucous membranes lining the digestive, respiratory and urogenital tracts and their related glands; and (6) sarcomas, derived from the connective tissues such as bone, muscle, cartilage, fascia, etc.
Auto-immunity. This phenomenon is described with immunity.
Advances in the last 100 years have gone fati-ocards solving the problems posed by external physical and biological agents that cause injury. The problems of degeneration and neoplasia, and to a less extent the errors of metabolism, now dominate the thoughts and efforts of medical scientists.
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