abducent abducting abduction accommodation acid-base balance acid-base equilibrium adaptation adducent adducting adduction adductive aerated afferent antidromic autacoidal automatic autonomic autoregulation cavernous contraction control efferent erect erectile excitable involuntary irritable isotonic oxygenated parenteral reflex reflexive sensibility sensitiveness sensitivity stimulation tonic tumid unaerated unoxygenated vegetative voluntary