Are all the physical symptoms of anxiety caused by adrenaline. By physical symptoms I mean the muscle tension chest tightness and high blood pressure. I guess if thats true then anxiety and anger are the same at least physiologically well are they? If not what is the chemical responsible for the physical symptoms of anxiety
Yes, they are actually similar, and they can be thought as two extremes of the same continuum. Many studies (here's a review by Lang and McTeague)suggest that the psychophysiological reactivity in the anxiety spectrum disorder is threat-related.
Ohman (2009) noted how predator-prey relationship is asymmetrical because there’s a larger pressure on prey than on predators.
Failure in defense against a predator determines the end of reproductive potential of prey animals. A hunting failure does not preclude future breeding.
This simple asymmetry implies that prey animals are evolutionarily shaped to exaggerate caution and avoidance of danger and this may provide a biological foundation for human anxiety disorders. In prey-predator race, prey arms became a strong capacity to associate subtle cues (smell, sounds) to the presence of a predator before its actual appearance. Learning to identify subtle signs is likely to be an evolutionary prepared ability, in the sense that very little environmental input is required. Therefore, from an evolutionary point of view, the organisms which learned to fear environmental threats faster had a survival and reproductive advantage.
LeDoux (2000) proposed a model according to which we have preferential pathways to encode emotional stimuli and particularly threat stimuli. The Thalamo-Amygdala pathway is a very fast road that brings the information to the amygdala (which extrapolates emotional contents from the stimuli) bypassing the cortex. It is a subcortical pathway which allows us to orient the attention toward the stimulus and to prepare our organism for responding (by sending of information from the amygdala to the brainstem which controls physiological responses). This "quick and dirty" pathway (dirty because it brings raw information that has to be integrated with the information from the cortices)is in common for fear and anxiety.
Of snakes and faces: an evolutionary perspective on the psychology of fear. Ohman (2009)
The anxiety disorder spectrum Lang and McTeague (2009).