Problem 2RCQ: How does pressure at the bottom of a body of water relate to... How does pressure at the bottom of a body of water relate to the weight of water above each square meter of the bottom surface? Chapter , Problem is solved.
The mutations that cause carcinoid tumors often affect the MEN1 gene, the same gene responsible for most familial neuroendocrine tumors and neuroendocrine cancers. But not much is known about exactly what causes these gene changes. Doctors do know that carcinoid tumors start out very small and grow slowly. When patients have parts of their stomach or small intestine removed to treat other diseases, taking a close look under the microscope often shows small groups of neuroendocrine cells that look like tiny carcinoids.
Causes of Carcinoid Syndrome. Carcinoid syndrome occurs when you have a carcinoid tumor that is secreting chemicalsâsuch as serotoninâinto your bloodstream. The chemicals cause your blood vessels to dilate, or open up. Most carcinoid tumors do not secrete chemicals that cause this condition. If a carcinoid tumor does secrete chemicals, the liver often neutralizes them before they can spread through your body. Typically, carcinoid syndrome is a sign that your cancer has spread to your liver or lungs. According to the National Cancer Institute, 58 to 64 percent of people with carcinoid tumors of the small intestine already have metastatic disease in the lymph nodes or liver. (NCI). The cause of these tumors is unknown. However, carcinoid tumors are most likely to form in your gastrointestinal tractâwhich includes your appendix, stomach, small intestine, colon, and rectumâor in your lungs.