KEY CONCEPTS Print Section Listen Hormones are signaling molecules that reach their target cells via the bloodstream. The hypothalamus is the key regulator of the endocrine system by releasing hormones…
KEY CONCEPTS Print Section Listen Both sleep and arousal are active processes mediated by specific brain regions and neurotransmitter systems. Sleep can be divided into two phases, nonrapid eye movement…
KEY CONCEPTS Print Section Listen Emotions activate physiologic, cognitive, and behavioral outputs that facilitate adaptive responses to salient external and internal stimuli. A crucial emotion, important in several mental disorders,…
KEY CONCEPTS Print Section Listen The autonomic nervous system plays a central role in maintaining homeostasis and regulates almost every organ system in the body. The major functional divisions are…
KEY CONCEPTS Print Section Listen The monoamine neurotransmitters (dopamine [DA], norepinephrine [NE], epinephrine, serotonin, and histamine), the related small molecule neurotransmitter, acetylcholine (ACh), and the neuropeptides, orexin A and B,…
KEY CONCEPTS Print Section Listen Neurons are the principal cells in the brain that process information. There is a great diversity of neuronal cell types based on morphology, chemistry, location,…
KEY CONCEPTS Print Section Listen Immune mechanisms, both intrinsic to the brain and spinal cord and derived from the periphery, are important in fighting central nervous system infections and mediating…
KEY CONCEPTS Print Section Listen The major excitatory neurotransmitter in the brain is glutamate; the major inhibitory neurotransmitter is γ-aminobutyric acid (GABA). Glutamate receptors comprise two large families, ligand-gated ion…
KEY CONCEPTS Print Section Listen The common designation of a group of neurotransmitters as purines is a misnomer; what are called purinergic signaling molecules are the nucleoside and nucleotide derivatives…
