Endocrine gland hormones at target cells "Permissiveness" is the situation in which a hormone cannot exert its full effects without the presence of another hormone. "Synergism" occurs when two or more hormones produce the same effects in a target cell and their results are amplified. "Antagonism" occurs when a hormone opposes or reverses the effect of another hormone. The endocrine glands belong to the body's control system. The hormones which they produce help to regulate the functions of cells and tissues throughout the body. Endocrine organs are activated to release their hormones by humoral, neural or hormonal stimuli. Negative feedback is important
Ciaccio's glands Ciaccio's glands Ciaccio's glands or Wolfring's glands are small tubular accessory lacrimal glands ("glandulae lacrimales accessoriae") found in the lacrimal caruncle of the eyelid. They are located in the upper border of the tarsus, approximately in the middle between the extremities of the tarsal glands. Sometimes they are situated slightly above the tarsus. There are usually 2 to 5 of these glands in the upper eyelid, and their function is to produce tears which are secreted onto the surface of the conjunctiva. They are named after Italian anatomist Giuseppe Vincenzo Ciaccio (1824–1901), who described these glands in 1874. They are