Structure | Lacrimal ducts

Structure

The lacrimal apparatus with all its components is mostly located in the inner (medial) corner of the eye. Each eye has its own tear apparatus. These lacrimal ducts are completely independent of each other and can also cause individual complaints.

The tear ducts are divided into a tear-producing and a tear-transporting part. Tear production Tears are produced by the tear gland located in the upper outer corner of the eye. Not only these glands contribute to the production of tears, but also so-called accessory (additional) tear glands are involved.

The actual lacrimal gland lies under the outer bony edge of the eye socket. It is divided by a muscle into a (lower) eyelid part and an (upper) eye socket part. This muscle is the lifting muscle of the upper eyelid (Musculus levator palpebrae).

The lacrimal gland produces about 5 to 7 microliters of tear fluid per minute. The accessory lacrimal glands are located in the fold of the conjunctiva, i.e. the place where the conjunctiva of the eye turns into the conjunctiva of the eyelid. You can see the lower corneal fold simply by pulling down the lower limb.

The upper fold remains hidden and can only be seen by turning it around or by folding the upper lid outwards. The accessory glands are located in both the upper and the lower fold. The different parts of the tear film are led from the glands through so-called excretory ducts to the surface of the eye.

Tear removal From the outer upper corner of the eye, the tears are distributed over the entire eye by the blinking of the eyelid. In the inner corner of the eye, the tears are then absorbed by small tear dots (lacrimal point). There are two lacrimal tear dots.

One is located at the upper, the other at the lower edge of the eyelid. If you look closely, you can see them on your eyes.The tears now enter the lacrimal sac through a tear duct. The lacrimal canals (Canaliculi lacrimales) act like a pump through their muscular embrace of a facial muscle and press the tears into the lacrimal sac (Saccus lacrimalis).

The further way now leads through the so-called Ductus nasolacrimalis (a passage that connects the lacrimal sac with the nasal cavity) in the lower nasal concha. So sooner or later, all our tears reach our nose. This explains why one always has to blow one’s nose when crying.

  • Lacrimal gland
  • Eye muscle
  • Eyeball
  • Iris (iris)
  • Pupil
  • Eye Socket