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The face and neck development of the human embryo refers to the development of the structures from the third to eighth week that give rise to the future head and neck.They consist of three layers, the ectoderm, mesoderm and endoderm, which form the mesenchyme (derived form the lateral plate mesoderm and paraxial mesoderm), neural crest and neural placodes (from the ectoderm). [1]
The endoderm lines the future auditory tube (pharyngotympanic Eustachian tube), middle ear, mastoid antrum, and inner layer of the tympanic membrane. Derivatives of this pouch are supplied by Mandibular nerve.
Excess tears flow through the nasolacrimal duct which drains into the inferior nasal meatus. This is the reason the nose starts to run when a person is crying or has watery eyes from an allergy, and why one can sometimes taste eye drops. This is for the same reason when applying some eye drops it is often advised to close the nasolacrimal duct ...
This arch divides into a maxillary process and a mandibular process, giving rise to structures including the bones of the lower two-thirds of the face and the jaw. The maxillary process becomes the maxilla (or upper jaw, although there are large differences among animals [11]), and palate while the mandibular process becomes the mandible or lower jaw.
In embryology, the nasal placode (or olfactory placode [1]) gives rise to the olfactory epithelium of the nose. Two nasal placodes arise as thickened ectoderm from the frontonasal process . They give rise to the nose , the philtrum of the upper lip , and the primary palate .
antihelix forms a 'Y' shape where the upper parts are: Superior crus (to the left of the fossa triangularis in the diagram) Inferior crus (to the right of the fossa triangularis in the diagram) Antitragus is below the tragus; Aperture is the entrance to the ear canal; Auricular sulcus is the depression behind the ear next to the head
The medial nasal process (nasomedial) on the inner side of each nasal pit merge into the intermaxillary segment and form the upper lip, crest, and tip of the nose. [1] The medial nasal processes merge with the maxillary prominences. The lateral nasal process from each side merge to form the alae of the nose. [1]
The topmost bony part of the nose is formed by the nasal part of the frontal bone, which lies between the brow ridges, [3] and ends in a serrated nasal notch. [4] A left and a right nasal bone join with the nasal part of the frontal bone at either side; and these at the side with the small lacrimal bones and the frontal process of each maxilla. [3]