AP PSYCHOLOGY

Detailed explanation-1: -Opioid medications function by mimicking natural endorphins, competing for receptor binding. In the acute setting, exogenous opiates inhibit the production of endogenous opiates while in the chronic setting, exogenous opiates inhibit the production of both endogenous opiates and mu-opioid receptors.

Detailed explanation-2: -Opioids produce euphoria, tranquility, and rewarding behavior. Euphoria is mediated by receptors. Activation of receptors produces dysphoria. The dopaminergic pathways, particularly involving the NAcc, are responsible for drug-induced reward.

Detailed explanation-3: -beta-Endorphin, an opiate-like peptide containing 31 amino acids, is localized to the pituitary gland from which it can be released into the circulation to act presumably at peripheral target organs. In the brain beta-endorphin is concentrated in the hypothalamus.

Detailed explanation-4: -Opioid peptides are peptides that bind to opioid receptors in the brain; opiates and opioids mimic the effect of these peptides. Such peptides may be produced by the body itself, for example endorphins. The effects of these peptides vary, but they all resemble those of opiates.