Tear bone

Skull side view:
1. frontal bone ( frontal )
2. parietal ( parietal )
3. nose ( nasal bone )
4. ethmoid ( ethmoid )
5. lacrimal ( lacrimal )
6. sphenoid (sphenoid)
7. occiput ( occipital bone )
8. temporal bone ( temporal bone )
9. cheekbone ( zygomatic bone )
10. upper jaw ( maxilla )
11 lower jaw ( mandible )

Skull of a sheep
os lacrimale marked in color

The tear bone ( os lacrimale ) is one of the skull bones and part of the facial skull. It is a pair of thin bone plates that form part of the eye socket and the side wall of the nasal cavity .

The lacrimal bone (in humans together with the upper jaw ) forms the tears sac pit ( Fossa sacci lacrimalis , also known as "tear funnel"), in which the tear sac lies. It also forms part of the lacrimal canal ( canalis lacrimalis ), in which the membranous teardrop-nasal duct ( ductus nasolacrimalis ) lies. The entrance to the lacrimal canal is the lacrimal foramen . In ruminants , the lacrimal bone is vesified ventrocaudally to the bulla lacrimalis .

In Paarhufern the lacrimal bone is pneumatized . This sinus is called lacrimal cave ( sine lacrimal called). In horses , the very large maxillary sinus extends into the tearbone.

The length of the tear bone is used in some animal species to identify subspecies . This is the case with the wild boar , for example .

literature

• Franz-Viktor Salomon: Bony skeleton . In: Franz-Viktor Salomon et al. (Hrsg.): Anatomie für die Tiermedizin . 3. Edition. Enke, Stuttgart 2015, ISBN 978-3-8304-1288-5 , pp. 99 .

Web links

Commons : Lacrimal bone  - collection of images, videos, and audio files

Individual evidence

1. ↑ Federative Committee on Anatomical Terminology (FCAT) (1998). Terminologia Anatomica . Stuttgart: Thieme