Apparent authority can legally be found, even if actual authority has not been given. There must be some act or some knowing omission on the part of the principal-if the agent alone acts to give the third party this false impression, then the principal is not bound.
An endogenous agonist for a particular receptor is a compound naturally produced by the body that binds to and activates that receptor. For example, the endogenous agonist for serotonin receptors is serotonin, and the endogenous agonist for dopamine receptors is dopamine. Full agonists bind to and activate a receptor with the maximum response that an agonist can elicit at the receptor. One example of a drug that can act as a full agonist is isoproterenol, which mimics the action of adrenaline at Î² adrenoreceptors.
Agonists and Antagonists. Agonists are chemicals that mimic the action of a particular neurotransmitter. They bind to receptors and generate postsynaptic potentials. Antagonists are chemicals that block the action of a particular neurotransmitter. They bind to receptors but canât produce postsynaptic potentials.Because they occupy the receptor site, they prevent neurotransmitters from acting.eurons, Hormones, and the Brain. 1  The Nervous System. 2  Neurons: Cells of the Nervous System. 3  Neurotransmitters. 4  Studying the Brain. 5  Structure and Functions of the Brain. 6  The Endocrine System. 7  Quick Review. 8  Review Questions. 9  Neurons, Hormones, and the Brain Quiz. 10  How to Cite This SparkNote.