antihistamine. Antihistaminic Pharmacology An agent that counteracts the effects of histamine released during allergic reactions by blocking histamineâH 1 receptors Adverse effects Dry mouth, drowsiness, urine retention in â, tachycardia.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.
While all of these Military service branches are uniformed, have. weapons, ranks and other such details that are. similar, the specific missions and focus of. each service is quite different. The US Army is charged as the primary land. combat force.
The Cavalry branch became the Armor branch in 1950, but the term Cavalry remains in use in the U.S. Army for mounted (ground and aviation) reconnaissance, surveillance, and target acquisition (RSTA) units based on their parent Combat Arms Regimental System (CARS) regiment.