Arachnophobia: An abnormal and persistent fear of spiders. Sufferers from arachnophobia experience undue anxiety, even though they realize that the risk of encountering a spider and being harmed by it is small or nonexistent. They may avoid going barefoot and may be especially alert when taking showers or getting into and out of bed.
- Arbitration agreement
Arbitration agreement: An arrangement in which the patient waives the right to sue the physician and, instead, agrees to submit any dispute to arbitration. Arbitration agreements are legal and binding. The arguments in their favor are that, for patients, the case can be settled faster, and more money can go to the patient (rather than […]
- Arboviral encephalitis
Arboviral encephalitis: Inflammation of the brain (encephalitis) caused by infection with an arbovirus, a virus transmitted by a mosquito, tick or another arthropod. Infection of vertebrates, including humans, occurs when an infected arthropod feasts upon them for a blood meal. There are a number of types of arboviral encephalitis. Those that occur in the US […]
Arbovirus: A class of viruses transmitted to humans by arthropods such as mosquitoes and ticks. The first two letters of the words arthropod’ and borne, make up the ‘arbo’ that now designates this group of viruses as arthropod-borne. The name arbovirus was coined in part by Dr. William C. Reeves (1916-2004) to connote the class […]
- Arch, aortic
Arch, aortic: The second section of the aorta following the ascending aorta. As it continues from the heart, it gives off the brachiocephalic trunk, and the left common carotid and subclavian arteries. The brachiocephalic trunk splits to form the right subclavian and the right common carotid arteries, which supply blood to the right arm and […]
- Arch, zygomatic
Arch, zygomatic: The bone that forms the prominence of the cheek. The zygomatic bone is also known as the zygoma, the zygomatic arch, malar bone, yoke bone. The word “zygomatic” comes from the Greek “zygon” meaning a yoke (as for oxen).