Final answer:
50% of carcinoid tumors are found in the small intestine, with the remainder spread throughout the GI tract. They are influenced by carcinogens and involve hormonal functions essential for digestion. Colorectal carcinoma is a significant type of cancer within the GI tract.
Step-by-step explanation:
Approximately 50% of carcinoid tumors are found in the small intestine. Carcinoid tumors are a type of neuroendocrine tumor that predominantly arise within the gastrointestinal (GI) tract. The remainder of carcinoid tumors are distributed throughout the GI tract, with occurrences in the stomach, colon, rectum, and other locations. Carcinoid tumors, like other types of cancer, can be influenced by exposure to certain carcinogens. The table referencing major carcinogens in the most common cancers demonstrates the link between specific carcinogens and cancer types such as lung, breast, colon, and stomach cancers.
The gastrointestinal tract also produces hormones responsible for digestion, with endocrine cells located throughout the mucosa of the stomach and small intestine. These cells are instrumental in releasing gastric juices necessary for food digestion, which emphasizes the complex function of the GI tract and the potential impact if these cells become cancerous.
Colorectal carcinoma is a major concern within the lower gastrointestinal tract and is one of the most common cancers affecting the colon and rectum. Illustrative of this, the Gross appearance of an opened large intestine specimen containing an invasive colorectal carcinoma clearly shows the severity of cancerous growth when cells multiply uncontrollably and form a tumor.