An 18-year-old female patient

is coming to the emergency office of the Department of Ophthalmology. She is

suffering from significant swelling of the upper eyelid. The eyelid is markedly

swollen, stiff and reddened in one spot. The eyelid is painful and causes

significant tearing of the entire eye. After examination of the eyelid, the

doctor concludes that it is a chalazion (eyelid cyst or Meibomian cyst). It is

an inflammation of the Meibomian gland of the eyelid, which can be seen in the

picture. What type of gland is it with regard to the mechanism of secretion?