antihistamine. a drug that counteracts the effects of histamine, a normal body chemical that among its actions is believed to cause the symptoms of persons who are hypersensitive to various allergens.hile the term antihistamine can broadly include any agent that blocks any histamine receptor, in practice it is usually used to denote those blocking the H 1 type of receptors (H1 receptor antagonists), those involved in allergic reactions.
The Executive Branch. From the President, to the Vice President, to the Cabinet, learn more about the Executive Branch of the government of the United States. The power of the Executive Branch is vested in the President of the United States, who also acts as head of state and Commander-in-Chief of the armed forces. The President is responsible for implementing and enforcing the laws written by Congress and, to that end, appoints the heads of the federal agencies, including the Cabinet.
THREE BRANCHES OF GOVERNMENT Printer Friendly (PDF) Our federal government has three parts. They are the Executive, (President and about 5,000,000 workers) Legislative (Senate and House of Representatives) and Judicial (Supreme Court and lower Courts). The President of the United States administers the Executive Branch of our government. The President enforces the laws that the Legislative Branch (Congress) makes. The President is elected by United States citizens, 18 years of age and older, who vote in the presidential elections in their states.