BMS291 Lecture Notes - Lecture 2: Reperfusion Injury, Ionizing Radiation, Decompression Sickness
Document Summary
Week 2 cellular responses to stress and injury. Cells respond to stress in physiological (normal) ways. Hypertrophy muscles enlarge in response to exercise. Atrophy increasing age can cause shrinkage in organs and tissues. Muscle atrophy through lack of use or stimulation. Cells respond to abnormal or excessive stress in pathological ways. Brain atrophy as a result of alzheimer"s disease. Cardiac hypertrophy in response to increased peripheral resistance and hypertension. Hyperplasia in response to hypersensitivity to growth factors in cancer. Ciliated epithelium of bronchi change to squamous epithelia in response to toxins in cigarette. Abnormal change cells no longer look like the original cell. Damages dna inhibiting cellular processes for maintenance and repair. Lack of sufficient oxygen to produce sufficient atp to drive na+-k+ pump. Results when oxygen returned to hypoxic tissue which generates free radicals. Highly reactive and interact with most nearby molecules. Normally removed by anti-oxidants within cells and mitochondria.
