title: Observations on altered patterns of response in old age.
mesh_terms: D000375:Aging / Q000276:immunology / Q000502:physiology*; D001341:Autonomic Nervous System / Q000502:physiology; D004723:Endorphins / Q000502:physiology; D006321:Heart / Q000502:physiology; D006801:Humans; D007109:Immunity
chemical_list: D004723:Endorphins