Answer :
Final answer:
The statement is false; the facial development involves multiple structures and begins earlier than week 6. The frontonasal process, maxillary processes, and mandibular portions of the first pharyngeal arch are all crucial. Facial development starts in the fourth week of gestation and includes the formation of the nasal cavity and jaw structures.
Explanation:
The statement is false; during facial development, the major structures that form the face include the frontonasal process, maxillary processes, and mandibular portions of the first pharyngeal arch, not just the frontonasal process and pharyngeal arch I. Facial development initiates earlier than week 6 in utero.The major facial structures during facial development are the frontonasal process and the pharyngeal arch I. This process begins during week 6 in utero.
Facial development in the human embryo includes the formation of various structures that give rise to the face. Around the fourth week of development, ectodermal tissue begins to invaginate to form olfactory pits, which eventually contribute to the nasal cavity. Simultaneously, the first pharyngeal arch divides into a maxillary and a mandibular portion. By the sixth week, these processes develop into the prominences that shape the face. As facial development progresses, structures such as the palatine bones form, contributing to the upper portion of the palette, while the mandible forms the lower jaw. This intricate process of development involves the coordination of several embryonic structures, including the ectoderm and endoderm, to ultimately shape the human face.
