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Unformatted text preview: www.brain101.info 1 HEAD AND NECK Development of the Head and Neck Cranial Nerves The Face Spinal Cord and Suboccipital Region Scalp and Cranial Fossa Eye and Orbit Triangles of the Neck Nose and Paranasal Sinuses The Mouth The Pharynx The Larynx The Ear Lymphatics DEVELOPMENT OF THE HEAD AND NECK NEUROCRANIUM: The part of the skull that surrounds the brain. CARTILAGINOUS NEUROCRANIUM (CHONDROCRANIUM): Neurocranium that develops by endochondral ossification (with a cartilaginous intermediate) MEMBRANOUS NEUROCRANIUM: That part of the skull that develops by membranous ossification. o The Frontal and Parietal bones are membranous. o Sutures are connections between bones. They allow for growth of the cranium . o Fontanelles occur at the intersection of two sutures. There are six of them. The Anterior Fontanelle stays open until the middle of the 2nd year . KNOW THAT! o Craniostenosis is the failure for the skull to expand due to malformed sutures. VISCEROCRANIUM: The rest of the skull, not overlying the brain. The Maxilla, Mandible, and facial skeleton. ENDOCHONDRAL VISCEROCRANIUM: o The middle ear bones are endochondral. o Styloid Process of Temporalis o Greater Cornu and Inferior body of the Hyoid o Laryngeal Cartilages MEMBRANOUS VISCEROCRANIUM: Maxillary and Mandibular Prominences SPECIAL VISCERAL EFFERENT (SVE) FIBERS: They all innervate Branchial Muscles , derived from Branchial arches They all originate from the Nucleus Ambiguus . GENERAL EFFERENT (GSE, GVE) FIBERS: They innervate muscles that are derived from somites . BRANCHIAL (PHARYNGEAL) ARCHES: They are primitive gills in the neck region of the embryo. In humans, we form a primitive gill but then we don't break down the membranes to form mature gills. This is an example of ontogeny recapitulating phylogeny, and so is the Mesonephric Duct of the Kidney, which develops and then disintegrates, being replaced by metanephric duct. Two different types of mesenchyme compose the Neural Arches: o Neural Crest: Forms the Arch Cartilages . The arch cartilages are made of neural crest! So this would be ectodermal (neural crest) mesenchyme . o Mesodermal: The rest of the neural arch is mesodermal mesenchyme. www.brain101.info 2 BRANCHIAL POUCHES: The outpocketing of endoderm, or the endodermal component on the inside of each arch. BRANCHIAL CLEFTS (GROOVES): The ectodermal ingrowths, found in between each set of arches. All of the clefts disappear except the 1st Branchial Cleft, which becomes the External Auditory Meatus . and the outer epithelium of the tympanic membrane. ARCH POUCH CARTILAGE MUSCLE NERVE Arch I Tubotympanic Recess, Eustachian Tube Meckel's Cartilage -- Malleus and Incus; Sphenomandibular Ligament Muscles of Mastication Trigeminal (V), Mandibular Branch Arch II Palatine Tonsils Reichert's Cartilage -- Stapes; Styloid Process; Lesser Cornu and superior part of hyoid bone; Stylohyoid Ligament...
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This note was uploaded on 01/30/2011 for the course BIO 210 taught by Professor S during the Spring '10 term at University of Toronto- Toronto.
- Spring '10