Glossary of Medical Terms

A network of sac-like structures and tubes in the cytoplasm (gel-like fluid) of a cell. Proteins and other molecules move through the endoplasmic reticulum. The outer surface of the endoplasmic reticulum can be smooth or rough. The rough endoplasmic reticulum has many ribosomes on its outer surface and makes proteins the cell needs. The smooth endoplasmic reticulum makes other substances that the cell needs, such as lipids (fats) and carbohydrates (sugars). The endoplasmic reticulum is a cell organelle.

A procedure in which a probe that sends out high-energy sound waves is inserted into the rectum. The sound waves are bounced off internal tissues or organs and make echoes. The echoes form a picture of body tissue called a sonogram. Endorectal ultrasound is used to look for abnormalities in the rectum and nearby structures, including the prostate. Also called ERUS, transrectal ultrasound, and TRUS.

One of several substances made in the body that can relieve pain and give a feeling of well-being. Endorphins are peptides (small proteins) that bind to opioid receptors in the central nervous system. An endorphin is a type of neurotransmitter.

A thin, tube-like instrument used to look at tissues inside the body. An endoscope has a light and a lens for viewing and may have a tool to remove tissue.

A procedure that uses an endoscope to remove abnormal growths or tissue from the lining of the digestive tract without open surgery. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. The endoscope may be passed through the mouth into the esophagus, stomach, or upper part of the small intestine, or it may be passed through the anus into the colon. Special tools are then inserted through the endoscope to remove the abnormal tissue, which will be checked under a microscope for signs of disease. Sometimes suction is used to remove the abnormal tissue, or a solution is injected around the abnormal tissue to separate it from other tissue before it is removed. Endoscopic mucosal resection may be used to help diagnose and treat early-stage cancers of the esophagus, stomach, small intestine, colon, or rectum. It may also be used to treat Barrett esophagus or other precancerous conditions of the digestive tract.

A procedure that uses an endoscope to examine and x-ray the pancreatic duct, hepatic duct, common bile duct, duodenal papilla, and gallbladder. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. The endoscope is passed through the mouth and down into the first part of the small intestine (duodenum). A smaller tube (catheter) is then inserted through the endoscope into the bile and pancreatic ducts. A dye is injected through the catheter into the ducts, and an x-ray is taken. Also called ERCP.

A procedure in which an endoscope is inserted into the body. An endoscope is a thin, tube-like instrument that has a light and a lens for viewing. A probe at the end of the endoscope is used to bounce high-energy sound waves (ultrasound) off internal organs to make a picture (sonogram). Also called endosonography and EUS.

A procedure to take a sample of tissue for examination under a microscope. An endoscope with an ultrasound probe and a biopsy needle at the end is inserted through the mouth into the esophagus. An endoscope is a thin, tube-like instrument that has a light and a lens for viewing. The ultrasound probe is used to bounce high-energy sound waves off internal organs and tissues to make a picture on a monitor. This picture helps the doctor see where to place the biopsy needle. Also called EUS-FNA.

A procedure that uses an endoscope to examine the inside of the body. An endoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease.

A procedure in which an endoscope is inserted into the body. An endoscope is a thin, tube-like instrument that has a light and a lens for viewing. A probe at the end of the endoscope is used to bounce high-energy sound waves (ultrasound) off internal organs to make a picture (sonogram). Also called endoscopic ultrasound and EUS.