http://www.animalresearch.info/en/medical-advances/154/neurotransmission-demonstrated/

Discussion of the discovery of neurotransmission.

http://nba.uth.tmc.edu/neuroscience/s1/chapter05.html

Mechanisms of Neurotransmitter Release: open-access ebook chapter with animations and self-quiz.

http://nba.uth.tmc.edu/neuroscience/s1/chapter06.html

Synaptic Transmission in the Central Nervous System: open-access ebook chapter with animations and self-quiz.

http://nba.uth.tmc.edu/neuroscience/s1/chapter07.html

Synaptic Plasticity: open-access ebook chapter with animations and self-quiz.

http://nba.uth.tmc.edu/neuroscience/s1/chapter14.html

Neuropeptides and Nitric Oxide: open-access ebook chapter with animations and self-quiz.

http://www.livescience.com/26496-endocrine-system.html

Review of the endocrine system.

https://www.youtube.com/watch?v=EVF6CyRR4Xs

Animation about G-protein activation.