HPA Axis:
http://dujs.dartmouth.edu/2011/02/the-phys...s/#.VyHmknrQrIU
http://www.simplypsychology.org/stress-biology.html
http://www.health.harvard.edu/staying-heal...stress-response
Cortisol + reward:
http://images.google.de/imgres?imgurl=http...57&biw=1366

ANS+HPA (pic)
http://flylib.com/books/en/2.159.1.12/1/

Video SAM axis vs HPA axis
https://www.youtube.com/watch?v=d-Kv-G5MTzY

Llabre, M. M., Spitzer, S., Siegel, S., Saab, P. G., & Schneiderman, N. (2004).
Applying latent growth curve modeling to the investigation of individual differences
in cardiovascular recovery from stress. Psychosomatic Medicine, 66,
29–41.

Sympathoneural and Adrenomedullary Responses to Mental Stress

Jason R. Carter1, David S. Goldstein2