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.
The Executive Branch. Article II of the United States Constitution created and empowered our executive branch of government. The United States president leads the executive branch, which also includes the president's advisors, the 15-member cabinet and all federal agencies. Our president serves as our chief executive, or commander-in-chief.