Face and neck development of the human embryo

Face and Neck Development of the Human Embryo

The development of the face and neck in the human embryo is a complex process that involves the interaction of several different types of cells and tissues. This process begins in the third week of embryonic development and continues until birth.

Pharyngeal Arches

The face and neck structures are primarily derived from the pharyngeal arches, which are a series of bulges that form on the lateral sides of the embryo. There are six pharyngeal arches, but only the first four contribute significantly to the formation of the face and neck.

• The first pharyngeal arch (also known as the mandibular arch) gives rise to the lower jaw (the mandible), two bones in the middle ear (the malleus and the incus), and the muscles of mastication (chewing).
• The second pharyngeal arch (also known as the hyoid arch) forms the upper part of the throat, including the styloid process, the stapes (another bone in the middle ear), and the muscles of facial expression.
• The third pharyngeal arch contributes to the formation of the lower part of the throat, including the hyoid bone and the pharyngeal muscles.
• The fourth pharyngeal arch forms the upper part of the larynx, including the thyroid cartilage and the cricoid cartilage.

Facial Prominences

The face is formed from five facial prominences, which are outgrowths of tissue that develop around the stomodeum (the primitive mouth). These include one frontonasal prominence, two maxillary prominences, and two mandibular prominences.

• The frontonasal prominence forms the forehead, the bridge of the nose, and the medial and lateral nasal prominences.
• The maxillary prominences form the upper jaw, the cheeks, and the lateral parts of the upper lip.
• The mandibular prominences form the lower jaw and the lower lip.

Neck Development

The neck is formed from the lower pharyngeal arches and the pharyngeal pouches. The third and fourth pharyngeal pouches give rise to the thymus and the parathyroid glands, respectively.

See Also

• Embryonic development
• Pharyngeal arch
• Stomodeum