Veins and their control.
D001794:Blood Pressure; D004644:Emotions; D006333:Heart Failure / Q000503:physiopathology; D006470:Hemorrhage / Q000503:physiopathology; D006801:Humans; D005082:Physical Exertion; D011187:Posture; D012119:Respiration; D013564:Sympathetic Nervous System / Q000502:physiology*; D013696:Temperature; D014655:Vascular Resistance; D014680:Veins / Q000187:drug effects / Q000294:innervation* / Q000502:physiology*