Essay on The Colon And The Rectum

863 Words Apr 16th, 2016 4 Pages
Under normal physiological conditions, the function of the colon and the rectum is responsible for the very last phase of digestion. Water is absorbed from the digested material (mostly liquid at this point) by the colon to form stool. Subsequently, the dehydrated stool then moves into the rectum for storage until signals are sent for its expulsion from the anus (Silverthorn, 2012).
When carcinomas occur in either the colon or the rectum, they are collectively labeled as colorectal cancer. Despite the different locations of these carcinomas, the similarities in their pathophysiology and their origin in the same type of cells allow them to be labeled as one collective disease (Ballinger & Anggiansah, 2007). Colorectal cancer can develop from benign tumors called polyps that arise in cells lining the colon or rectum. When these rapidly dividing growths undergo further DNA changes, they may become malignant, resulting in the spread of cancerous cells into the walls of the colon or rectum, blood vessels, lymph nodes and other organs. These DNA changes involve turning off a number of tumor-suppressor and DNA repair genes while simultaneous activating oncogenes which will allow the colonic epithelial cells to grow rapidly. This selective and rapid growth drives the transformation process from normal colonic epithelium  polyp  invasive colorectal cancer (Ballinger & Anggiansah). This pathophysiological process is known as the adenoma-carcinoma sequence. In this sequence,…

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