 Apocrine glands of eyelashes (glands of Moll) are small sweat glands with unbranched sinuous tubules that begin as a simple spiral.
 Accessory lacrimal glands are compound serous tubuloalveolar glands that have distended lumina. They are located on the inner surface of the upper eyelids (glands of Wolfring) and in the fornix of the lacrimal sac (glands of Krause).
All glands of the human eyelid are innervated by neurons of the autonomic nervous system, and their secretion is synchronized with the lacrimal glands by a common neurotransmitter, vasoactive intestinal polypeptide (VIP).
The eyelashes emerge from the most anterior edge of the lid margin, in front of the openings of the Meibomian glands. The lashes are short, stiff, curved hairs and may occur in double or triple rows. The lashes on the same eyelid margin may have different lengths and diameters.
The lacrimal gland produces tears that moisten the cornea and pass to the nasolacrimal duct.
Tears are produced by the lacrimal glands and to a lesser degree by the accessory lacrimal glands. The lacrimal gland is duct of tarsalgland glands apocrine glands of eyelids (of Moll) eyelids (of Moll) eyelash sebaceous glands(of Zeis) of eyelashes (of Zeis)
FIGURE 24.16 • Structure of the eyelid. a. This schematic drawing of the eyelid shows the skin, associated skin appendages, muscles, tendons, connective tissue, and conjunctiva. Note the distribution of multiple small glands associated with the eyelid and observe the reflection of the palpebral conjunctiva in the fornix of the lacrimal sac to become the bulbar conjunctiva.
b. Photomicrograph of a sagittal section of the eyelid stained with picric acid for better visualization of epithelial components of the skin and the numerous glands. In this preparation, muscle tissue (i.e., orbicularis oculi muscle) stains yellow, and the epithelial cells of skin, conjunctiva, and glandular epithelium are green. Note the presence of the numerous glands within the eyelid. The tarsal (Meibomian) gland is the largest gland, and it is located within the dense connective tissue of the tarsal plates. This sebaceous gland secretes into ducts opening onto the eyelids. 20. Inset. Higher magnification of a tarsal gland from the boxed area, showing the typical structure of a holocrine gland. 60.
located beneath the conjunctiva on the upper lateral side of the orbit (Fig. 24.17). The lacrimal gland consists of several separate lobules of tubuloacinar serous glands. The acini have large lumina lined with columnar cells. Myoepithelial cells, located below the epithelial cells within the basal lamina, aid in the release of tears. Approximately 12 ducts drain from the lacrimal gland into the reflection of conjunctiva just beneath the upper eyelid, known as the fornix of the lacrimal sac.
Tears drain from the eye through lacrimal puncta, the small openings of the lacrimal canaliculi, located at the medial angle. The upper and lower canaliculi join to form the common canaliculus, which opens into the lacrimal sac. The sac is continuous with the nasolacrimal duct, which opens into the nasal cavity below the inferior turbinate. A pseudostratified ciliated epithelium lines the lacrimal sac and the nasolacrimal duct. Dacryocystitis is an infammation of the lacrimal sac that is frequently caused by an obstruction of the nasolacrimal duct. It can be acute, chronic, or congenital. It usually affects older individuals and is most often secondary to stenosis of the lacrimal canaliculi.