Cellular Enviroment Assignment Example | Topics and Well Written Essays - 500 words

Cellular Enviroment - Assignment Example 16-17). According to McCance & Huether (2010), cellular swelling is the initial sign of cell injury; triggered by direct damage to the cell membrane, hypoxia, or damage to the electrolyte-pumping enzymes. The most common cause of cellular injury is hypoxia, which disrupts the cell’s capability of maintaining fluid homeostasis due to deficiency in oxygen. The main cellular mechanisms of cell injury include loss of calcium homeostasis, ATP depletion, oxidative stress, damage to mitochondria, and increases permeability of membranes. These adaptive mechanisms thus fail to maintain normal homeostasis, leading to a fall in oxidative phosphorylation. This triggers the depletion of cellular ATP and the swelling of mitochondria. What follows next is the failure of membrane calcium pumps, protein synthesis, NaK ATPase pump, and generation of reactive oxygen metabolites. This leads to an influx of Na+ and water, efflux of K+, entry of free calcium into the cytoplasm, and a drop in intracellular pH. This results to accumulation of water into the cell triggered by failure of membrane NaK ATPase pump, and cellular swelling due to swelling of endoplasmic reticulum (p. 54-92). Cellular swelling during the early stages is a reversible lesion, which is non-lethal; however, it becomes reversible if hypoxia persists for some time depending on the oxygen demands of the cell. An irreversible injury leads to cell death, mainly via apoptosis or necrosis. Aging is a gradual deterioration of a mature organism leading to irreversible structural changes as time passes by. According to Brashers (2006), cellular changes facets of aging include hypertrophy, and the weakened capability to undergo mitosis. Cellular function is impaired by the deposition of lipids (lipid peroxidation products), programmed changes in gene expression, damage from free radicals and advanced glycation end products. These