Splanchnocranium

Splanchnocranium is a part of the skull that is derived from the embryonic pharyngeal arches. It forms the facial bones and includes the bones that support the gills in fish and some amphibians. In mammals, it contributes to the bones of the lower face and neck.

Development

The splanchnocranium originates from the neural crest cells, which migrate from the neural tube to the pharyngeal arches. Each arch gives rise to specific bones and structures. For example, the first arch forms the mandible and maxilla, while the second arch forms the stapes, styloid process, and part of the hyoid bone.

Structure

The splanchnocranium includes several bones, such as the ethmoid bone, vomer, inferior nasal conchae, mandible, maxilla, palatine bone, zygomatic bone, lacrimal bone, and hyoid bone. These bones form the lower face, support the oral cavity, and provide attachment points for muscles of mastication and facial expression.

Function

The splanchnocranium supports the gills in fish and some amphibians, allowing for respiration. In mammals, it supports the structures of the lower face and neck, enabling functions such as mastication, speech, and facial expression.

Clinical significance

Abnormalities in the development of the splanchnocranium can lead to conditions such as Pierre Robin sequence, Treacher Collins syndrome, and Goldenhar syndrome. These conditions are characterized by facial deformities, such as micrognathia, cleft palate, and ear anomalies.

See also

• Chondrocranium
• Dermatocranium
• Pharyngeal arch