Cell injury and cell death
“Common biochemical themes are important to understanding cell injury and cell death regardless of the injuring agent” (Heuther & McCance, 2012). Cellular injury arises when a cell is unable to sustain homeostasis. The injury can be reversed if the cell can recover from whatever damage was done but if it does not recover the cell will die. The three common forms of cell injury are hypoxic injury, free radicals and reactive oxygen species injury, and chemical injury.
The most common form of cell injury is hypoxic injury, or hypoxia, the deficiency of adequate oxygen. Ischemia is the most common cause of tissue hypoxia and is caused from a decrease in blood flow. Hypoxia can also be caused by a reduced amount of oxygen in the air, loss of hemoglobin, diseases of the respiratory and cardiovascular systems, and decreased production of red blood cells. Cardiac ischemia is one of the most recognizable forms of hypoxic injury and is caused by a blockage in the coronary arteries of the heart. Once the blood flow to heart tissue decreases or stops completely, the heart tissue is damaged and can lead to further complications including a myocardial infarction. Another form of cell injury is free radicals and reactive oxygen species. “An important mechanism of cellular injury is injury induced by free radicals, especially by reactive oxygen species (ROS); this form of injury is called oxidative stress” (Heuther and McCance, 2012). Free radicals are produced by cells and are crucial to normal cellular metabolism. Free radicals can form damaging chemical bonds with lipids, proteins, and carbohydrates. The most commonly defined free radicals are the reactive oxygen species (ROS) which contribute to mitochondrial dysfunction and are linked to many human diseases and the aging process. According to a holistic physician, Dr. Jill Marjama-Lyons, “oxidative stress is one of the leading theories as to what might cause dopamine cell death in Parkinson’s disease” (2003).
The most common form of cell injury is hypoxic injury, or hypoxia, the deficiency of adequate oxygen. Ischemia is the most common cause of tissue hypoxia and is caused from a decrease in blood flow. Hypoxia can also be caused by a reduced amount of oxygen in the air, loss of hemoglobin, diseases of the respiratory and cardiovascular systems, and decreased production of red blood cells. Cardiac ischemia is one of the most recognizable forms of hypoxic injury and is caused by a blockage in the coronary arteries of the heart. Once the blood flow to heart tissue decreases or stops completely, the heart tissue is damaged and can lead to further complications including a myocardial infarction. Another form of cell injury is free radicals and reactive oxygen species. “An important mechanism of cellular injury is injury induced by free radicals, especially by reactive oxygen species (ROS); this form of injury is called oxidative stress” (Heuther and McCance, 2012). Free radicals are produced by cells and are crucial to normal cellular metabolism. Free radicals can form damaging chemical bonds with lipids, proteins, and carbohydrates. The most commonly defined free radicals are the reactive oxygen species (ROS) which contribute to mitochondrial dysfunction and are linked to many human diseases and the aging process. According to a holistic physician, Dr. Jill Marjama-Lyons, “oxidative stress is one of the leading theories as to what might cause dopamine cell death in Parkinson’s disease” (2003).
Cited: M.D. Marjama-Lyons, J., & Shomon, M., (2003). What Your Doctor May Not Tell You About: Parkinson’s Disease, A Holistic Program for Optimal Wellness. New York, NY: Warner Books, Inc. Heuther, S., & McCance, K., (2012), Understanding Pathophysiology, 5th Edition. St. Louis, MI: Mosby.