. Human embryology and morphology. Embryology, Human; Morphology. DEVELOPMENT OF THE processes separate the buccal from the nasal cavities, forming the roof of the one and the floor of the other (Fig. 7). The horizontal palatal plates meet first in front; the process of fusion spreads backwards, and by the end of the second month it is complete. premaxilla naso-pal. for. palatal proc. of max. palatine foramen, palatal proc. of palatine Fig. 9.—Showing the Hard Palate at birth. The premaxillary part is formed from the Mesial Nasal Processes ; the remainder by the Palatal Plates of the Ma
. Human embryology and morphology. Embryology, Human; Morphology. DEVELOPMENT OF THE processes separate the buccal from the nasal cavities, forming the roof of the one and the floor of the other (Fig. 7). The horizontal palatal plates meet first in front; the process of fusion spreads backwards, and by the end of the second month it is complete. premaxilla naso-pal. for. palatal proc. of max. palatine foramen, palatal proc. of palatine Fig. 9.—Showing the Hard Palate at birth. The premaxillary part is formed from the Mesial Nasal Processes ; the remainder by the Palatal Plates of the Maxillary Processes. The condition of cleft palate is due to a partial or sometimes a complete failure of the process of fusion. Bones formed in each Maxillary Process.—The zygomatic process of the temporal, the malar, and the greater part of the superior maxillary are formed directly from the connective tissue within the process. They are membrane-formed bones. - Pterygo-palatine Bar.—Two other bones formed in this process have quite a different history. The internal pterygoid plate, which is originally a separate bone, and the palate, are developed over cartilage. When the maxillary process grows forwards from the base of the mandibular arch, it carries with it a prolongation of the cartilaginous bar which forms the skeletal basis of that arch. The cartilaginous bar is known as the pterygo-palatine, and in the membrane over this bar the pterygoid (internal pterygoid process) and palatal bones are developed (Fig. 10 A, B, C). From the posterior end of this bar is developed the incus in mammals and the quadrate bone in birds and reptiles. In birds and reptiles the lower jaw articulates with the quadrate bone (Fig. 10 B), and on the quadrate the superior maxilla is supported by the pterygoid and palate bones. In amphibians the quadrate, pterygoid and palate form a continuous bar of. Please note that these images are extracted from scanned page images that may have been digit
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectembryol, bookyear1902
