Volcanologists classify eruptions into several different types. Some are named for particular volcanoes where the type of eruption is common; others concern the resulting shape of the eruptive products or the place where the eruptions occur. Here are some of the most common types of eruptions:
The study of anxiety is at the root of psychoanalytic explorations of the human condition. Anxiety is a warning signal that danger is present and that overwhelming emotions may be felt, giving rise to unmanageable helplessness. The danger may be perceived as arising from internal or external sources, and be the response to a variety of powerful phantasies in the unconscious mind.
The anatomy of anxiety. Anxiety is a reaction to stress that has both psychological and physical features. The feeling is thought to arise in the amygdala, a brain region that governs many intense emotional responses. As neurotransmitters carry the impulse to the sympathetic nervous system, heart and breathing rates increase, muscles tense, and blood flow is diverted from the abdominal organs to the brain. In the short term, anxiety prepares us to confront a crisis by putting the body on alert.