Meckel's cartilage

The ( paired ) Meckel's cartilage ( Meckel's cartilage, the cartilage Meckeli, named after its discoverer JF Meckel (1820 ) is the embryonic precursor of the mandible of the gnathostomes. Traditionally puts you him serial homologous a Ceratobranchiale the gill arch (which is not necessary for thought ). in part, he is wrapped in the ontogeny of covering bones (eg, the tooth-bearing dentary ), sometimes by replacing bone (the largest is the articular ) displaced ( ossify front and rear end even in humans yet). in teleosts remains the cartilage throughout life contributes a functionally important element in the lower jaw, the elasticity.

In mammalian forms of Meckel's cartilage, as soon as the dental occurs as the sole mandible in appearance, only the basis for the series of the ossicles ( the primary jaw joint between palatoquadrate and Meckel bones became the hinge between the anvil and hammer ). Thus, only the dorsal portion, the former primary jaw joint, ie the malleus-incus joint, articulatio incudomallearis retained and later forms a part of the sound -conducting apparatus of the middle ear.

Is the stapes, incus from the cartilage of the proximal end of the second branchial arch. The rest of the first distal portion forms a long tracheal cartilage, the Reichert 's cartilage - named after Karl Reichert Bogislaus - that is after his chondral ossification of the styloid process and unites with the temporal bone. The middle portion is styloideum for ligament and the distal portion of the small ossified hyoid horn, Cornu minor ossis hyoidei.

The Meckel's cartilage is a tracheal cartilage of the first branchial arch, it acts as embryonic and temporary lead for the lower jaw the system ( mandible ), which laterally forms of Meckel cartilage via endochondral bone formation, endochondral ossification to this, the cartilage builds completely and is bone replaced.

In the embryological development of Meckel's cartilage is gradually reduced until week 24. Located on both sides develop at the two ends of the dorsal part of the ossicles, ossicles auditus, more precisely, the hammer, anvil and the Malleus, Incus and the ligamentum sphenomandibular.