. A laboratory manual and text-book of embryology. Embryology. TRANSVERSE SECTIONS OF A TEN MM. PIG EMBRYO 135 thelium. The first, second and third branchial arches show on either side of the section, the third being slightly sunken in the cervical sinus. The dorsal diverticula of the third pharyngeal pouches extend toward the ectoderm of the third branchial cleft. The ventral diverticula or thymic anlages may be traced caudad in the series. The floor of the pharynx is sectioned through the epiglottis. Ventral to the pharynx are sections of the third aortic arches and the solid cords of the me
. A laboratory manual and text-book of embryology. Embryology. TRANSVERSE SECTIONS OF A TEN MM. PIG EMBRYO 135 thelium. The first, second and third branchial arches show on either side of the section, the third being slightly sunken in the cervical sinus. The dorsal diverticula of the third pharyngeal pouches extend toward the ectoderm of the third branchial cleft. The ventral diverticula or thymic anlages may be traced caudad in the series. The floor of the pharynx is sectioned through the epiglottis. Ventral to the pharynx are sections of the third aortic arches and the solid cords of the median thyreoid gland. Dorsally the section passes through the spinal cord and first pair of cervical ganglia. Between the cord and pharynx, named in order, are the internal jugular veins, the hypoglossal nerve, and the nodose ganglion of the vagus. Lateral to the ganglion Myelencephahn. Neural cavity Hoots of n. hypoglossus Int. jugular vein vagus et accessorius Descend Aorta !\l. facialis Br. arch 2 Tongue Mandible Maxillary process Telencephalon Fig. 125.—Transverse section passing through the first and second pharyngeal pouches of a 10 mm. pig embryo. X is the external branch of the n. accessorius, and mesial to the ganglia are the small descending aorta. Section through the Fourth Pharyngeal Pouches (Fig. 127).—This region is marked by the disappearance of the head and the appearance of the heart in the pericardial cavity. The tips of the atria are sectioned as they project on either side of the bulbus cordis. The bulbus is divided into the aorta and pulmonary artery, the latter connected with the right ventricle, which has spongy muscular walls. The pharynx is crescentic and continued laterally as the small fourth pharyngeal pouches. Into the mid-ventral wall of the pharynx opens the vertical slit of the trachea. A section of the vagus complex is located between the descending. Please note that these images are extracted from scanned
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectembryology, bookyear1
