1. Opioids and immune modulation: more questions than answers
M Al-Hashimi, S.W.M. Scott, J.P. Thompson, D.G. Lambert 
British Journal of Anaesthesia 
Volume 111, Issue 1, Pages (July 2013)
DOI: /bja/aet153
Copyright © 2013 The Author(s) Terms and Conditions

2. Fig 1
Immune-regulation. The top half illustrates the process of immune cell generation from stem cells into individual cell populations which then exert feedback control onto stem cell maturation. The bottom half illustrates antigen-antibody immune function. Antigens will be bound by antigen presenting cells (APC like macrophages) which in turn will activate T-helper precursor cells and end up forming an antigen specific T-helper cell that once formed can be directly activated by the antigen and the APC. These antigen specific T cells help B cells (with some help from the APC) to form antibodies by antibody producing cells, a process that exerts a feedback control mechanism on the APC. Another function of the APC is to activate the T inducer and T stimulator cells, a process that has feedback loop control as well affecting the function of the APC.
British Journal of Anaesthesia  , 80-88DOI: ( /bja/aet153)
Copyright © 2013 The Author(s) Terms and Conditions

3. Fig 2
Potential sites of immunomodulatory effects of opioids that can be categorized into central and peripheral effects.
British Journal of Anaesthesia  , 80-88DOI: ( /bja/aet153)
Copyright © 2013 The Author(s) Terms and Conditions

4. Fig 3
Effects of opioids on markers of HPA axis activity. ACTH, adrenocorticotrophic hormone.
British Journal of Anaesthesia  , 80-88DOI: ( /bja/aet153)
Copyright © 2013 The Author(s) Terms and Conditions