Ebook Inderbir singh’s human embryology: Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook Inderbir singh’s human embryology: Part 2
Ebook Inderbir singh’s human embryology: Part 2
Chapter 11Face, Nose and PalateHIGHLIGHTS•The stomatodeum (future mouth) is a depression bounded cranially by a bulging produced by the brain, and cau Ebook Inderbir singh’s human embryology: Part 2udally by a bulging produced by the pericardial cavity.•Three prominences appear around the stomatodeum. These are the frontonasal process (above), and the right and left mandibular arches (first pharyngeal arctics)•The mandibular arch divides into a maxillary process and a mandibular process.•The r Ebook Inderbir singh’s human embryology: Part 2ight and left mandibular processes meet in the midline and fuse. They form the lower lip and lower jaw.•The upper lip is formed by fusion of the frontEbook Inderbir singh’s human embryology: Part 2
onasal process with the right and left maxillary processes. Failure to fuse completely leads to various forms of harelip.•The cheeks arc formed by fusChapter 11Face, Nose and PalateHIGHLIGHTS•The stomatodeum (future mouth) is a depression bounded cranially by a bulging produced by the brain, and cau Ebook Inderbir singh’s human embryology: Part 2om an ectodermal thickening, the nasal placode, appears over the frontonasal process. The placode gets depressed below the surface to form the nasal pit. The nasal pits enlarge to form the nasal cavity.•Paranasal sinuses appear as outgrowths from the nasal cavity.•The palate is formed by fusion of t Ebook Inderbir singh’s human embryology: Part 2hree components. These arc the right and left palatal processes (arising from the maxillary process): and the primitive palate (derived from the frontEbook Inderbir singh’s human embryology: Part 2
onaeal procese). Deficiency in fusion lead* * to various forms of cleft palate.INTRODUCTION•During the 4th week of development, after die formation ofChapter 11Face, Nose and PalateHIGHLIGHTS•The stomatodeum (future mouth) is a depression bounded cranially by a bulging produced by the brain, and cau Ebook Inderbir singh’s human embryology: Part 2loping brain cranially-Pericardium caudally•The floor of the stomatodeum is formed by the buccopharyngeal membrane, which separates it from the foregut. On each side, the stomatodeum Is bounded by first arch.•Soon, mesoderm covering the developing forebrain proliferates and forms a downward projecti Ebook Inderbir singh’s human embryology: Part 2on that overlaps the upper part of the stomatodeum. Thisdownward projection is called the frontonasal process (Fig. 11.2).•the pharyngeal arches are lEbook Inderbir singh’s human embryology: Part 2
aid down in the lateral and ventral walls of the most cranial part of the foregut (chapter 9, Fig. ‘1.1 B). These are also, therefore, in very close rChapter 11Face, Nose and PalateHIGHLIGHTS•The stomatodeum (future mouth) is a depression bounded cranially by a bulging produced by the brain, and cau Ebook Inderbir singh’s human embryology: Part 2 the stomatodeum-Unpaired'. Frontonasal process from above.-Paired: First pharyngeal (or mandibular) arch of each side (Fig. 11.3A).mebooksfree.comFace, Nose and Palate153•Each mandibular arch forms the lateral wall of the stomatodeum (Fig. 11.3A). This arch gives off a bud from its dorsal end. This Ebook Inderbir singh’s human embryology: Part 2 bud is called the maxillary process (Fig. 11.38). It grows venlromedially cranial to the main part of the arch which is now called the mandibular proEbook Inderbir singh’s human embryology: Part 2
cess.•The five prlmordia for face development are an unpaired frontonasal process and paired maxillary and mandibular processes.Fig. 11.2: Formation oChapter 11Face, Nose and PalateHIGHLIGHTS•The stomatodeum (future mouth) is a depression bounded cranially by a bulging produced by the brain, and cau Ebook Inderbir singh’s human embryology: Part 2tomatodeum (Fig. 11.4A) on either side of midline. These are called the nasal placodes. The formation of these placodes is induced by the underlying forebrain. The placodes soon sink below the surface to form nasal pits (Fig. 11.4B). The pits are continuous with the slornatodeum below. The edges of Ebook Inderbir singh’s human embryology: Part 2each pit arc raised above the surface: the medial raised edge is called the medial nasal process and the lateral edge is called the lateral nasal procEbook Inderbir singh’s human embryology: Part 2
ess. Lateral and cranial to the nasal placodes pair of thickenings appear and are called lens placodes.DEVELOPMENT OF VARIOUS PARTS OF FACEWe arc now Chapter 11Face, Nose and PalateHIGHLIGHTS•The stomatodeum (future mouth) is a depression bounded cranially by a bulging produced by the brain, and cau Ebook Inderbir singh’s human embryology: Part 2 are shown in Table 11.1.Lower LipThe mandibular processes of the two sides grow toward each other (Fig. 11.38) and fuse in the midline (Fig. 1 l.'1A). They now form the lower margin of the stomatodcum. If it is remembered that the mouth develops from the stomatodeum, it will be readily understood t Ebook Inderbir singh’s human embryology: Part 2hat the fused mandibular processes give rise to the lower lip. and to the lower jaw ( Fig. 11.7).Upper LipChapter 11Face, Nose and PalateHIGHLIGHTS•The stomatodeum (future mouth) is a depression bounded cranially by a bulging produced by the brain, and cauChapter 11Face, Nose and PalateHIGHLIGHTS•The stomatodeum (future mouth) is a depression bounded cranially by a bulging produced by the brain, and cauGọi ngay
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