antagonist. 1. a muscle that counteracts the action of another muscle, its agonist. 2. a drug that binds to a cellular receptor for a hormone, neurotransmitter, or another drug blocking the action of that substance without producing any physiological effect itself.
in the body (Figure 20â1). In general, the more widely a cancer spreads, the harder it becomes to eradicate. It is generally metastases that kill the cancer patient. Cancers are traditionally classified according to the tissue and cell type from which they arise. Carcinomas are cancers arising from epithelial cells, and they
Urothelial carcinoma is the most common type of bladder cancer and occurs in 90 percent of the cases, as noted by the John Hopkins University Department of Pathology. It is further divided into two subtypes: superficial cancers and muscle tumors.