Antrum: A general term for a nearly closed cavity or chamber. For example, the antrum of the stomach (gastric antrum) is a portion before the outlet, which is lined by mucosa and does not produce acid. The paranasal sinuses can be referred to as the frontal antrum, ethmoid antrum, and maxillary antrum.
- Ants, fire
Ants, fire: Originally from S. America. Among the worst insect pests ever to invade the U.S. Red or yellowish ants of small-to-medium size with a severe sting that burns like fire. They normally feed on small insects but, with denser populations, they eat seeds and seedling plants, damage grain and vegetable crops, invade kitchens, attack […]
- Ants, velvet
Ants, velvet: Common in most parts of the world including the Southern and Southwestern U.S., velvet ants are not true ants but rather parasitic wasps. Their sting can trigger allergic reactions. Avoidance, prompt treatment and, in selected cases, allergy injection therapy are useful.
- ANUG (acute necrotizing ulcerative gingivitis)
ANUG (acute necrotizing ulcerative gingivitis): This is trench mouth, a progressive painful infection with ulceration, swelling and sloughing off of dead tissue from the mouth and throat due to the spread of infection from the gums. Certain germs (including fusiform bacteria and spirochetes) have been thought to be involved, but the full story behind this […]
- Anus, imperforate
Anus, imperforate: A birth defect in which the rectum is a blind alley and there is no anus. Imperforate anus occurs in about 1 in 5,000 births, and it can be corrected by surgery.
A feeling of apprehension and fear, characterized by physical symptoms such as palpitations, sweating, and feelings of stress.