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Atlas of Human Embryos Chapter   Figure

C-2 spinal ganglion, C-2 ventral primary ramus, aortic arch 3, auricular hillock, branchial arch 2, branchial arch 3, branchial groove 1, carotid duct, choroid fissure, corneal ectoderm, deep lens epithelium, dense mesenchyme of branchial arch 2, dorsal portion of pharyngeal pouch 3, ependymal layer, ependymal layer of spinal cord, epithalamus, inferior ganglion of vagus nerve (CN X), intraretinal space (optic vesicle cavity), lens vesicle, loose mesenchyme in optic cup cavity, mandibular nerve, mantle layer, mantle layer of spinal cord, marginal layer, marginal layer of spinal cord, maxillary nerve (CN V₂), maxillary vein, optic stalk lumen, pigmented layer of retina, precardinal vein, premuscle mass of tongue, primitive oral fissure, primitive pharynx, spinal accessory nerve (CN XI), sternocleidomastoid / trapezius premuscle mass, stomodeum, sulcus dorsalis, superficial lens epithelium, thyroglossal duct

A section through the optic stalk lumen and lens vesicle.

Observe:
1. The dense mesenchyme of the second branchial arch where the facial nerve has terminated.
2. The dorsal portion of the third pharyngeal pouch where the caudal (inferior) parathyroid gland develops.
3. The parts of the lens vesicle and layers of the optic cup.
4. The three layers of the spinal cord.
5. The thyroglossal duct in the midline between the primitive pharynx and tongue musculature.


Keywords: C-2 spinal ganglion, C-2 ventral primary ramus, aortic arch 3, auricular hillock, branchial arch 2, branchial arch 3, branchial groove 1, carotid duct, choroid fissure, corneal ectoderm, deep lens epithelium, dense mesenchyme of branchial arch 2, dorsal portion of pharyngeal pouch 3, ependymal layer, ependymal layer of spinal cord, epithalamus, inferior ganglion of vagus nerve (CN X), intraretinal space (optic vesicle cavity), lens vesicle, loose mesenchyme in optic cup cavity, mandibular nerve, mantle layer, mantle layer of spinal cord, marginal layer, marginal layer of spinal cord, maxillary nerve (CN V₂), maxillary vein, optic stalk lumen, pigmented layer of retina, precardinal vein, premuscle mass of tongue, primitive oral fissure, primitive pharynx, spinal accessory nerve (CN XI), sternocleidomastoid / trapezius premuscle mass, stomodeum, sulcus dorsalis, superficial lens epithelium, thyroglossal duct

Source: Atlas of Human Embryos.