Axial Skeleton - Skull Neurocranium Dermatocranium Splanchnocranium.
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Axial Skeleton - Skull Neurocranium Dermatocranium Splanchnocranium Slide 2 Dermatocranium Phylogeny membrane bone which evolved from dermal armor Roofing bones Along side and above brain Slide 3 Roofing Bones Nasal Frontal Parietal Orbital Lacrimal Jugal = Infraorbital = Zygomatic Squamosal Slide 4 Slide 5 Slide 6 Slide 7 Look at the Skull & Lower Jaw components page. Examine the roofing bones. Slide 8 Upper jaw Premaxilla Maxilla Slide 9 Slide 10 Slide 11 Lower Jaw Dentary - largest Splenial small, dorsomedial Surangular - lateral Angular medial, becomes typanic bulla Coronoid medial Prearticular medial & caudal becomes anterior malleus in mammals Slide 12 Slide 13 Slide 14 Slide 15 Key Points Look at upper and lower jaw dermatocranium bones on Skull & Lower Jaw Components page Give an example of homology. What trend do you see in lower jaw evolution? Slide 16 Primary Palate Bones Roof of oropharyngeal cavity in fish, amphibians Roof of nasal cavity in amniotes Slide 17 Slide 18 Primary Palate Vomer Palatine Pterygoid Slide 19 Slide 20 Slide 21 Primary Palate Examine Skull & Lower Jaw Components page Slide 22 Dermatocranium Operculum Slide 23 Key Point Describe dermatocranium bones in the shark Slide 24 Axial Skeleton - Skull Neurocranium Dermatocranium Splanchnocranium Visceral skeleton Slide 25 Splanchnocranium Supports & allows movement of jaws, gill, tongue Associated with hearing Ancient in evolution Replacement bone Slide 26 Splanchnocranium Typically 6 gill slits between Visceral arches A typical visceral arch that is gill in function has five segments Pharyngobranchial Epibranchial Ceratobranchial Hypobranchial Basibranchial Slide 27 Slide 28 Slide 29 Splanchnocranium Mandibular arch = Visceral Arch I Palatoquadrate Mandibular = Meckels Cartilage Slide 30 Slide 31 Slide 32 Splanchnocranium Hyoid arch = Visceral arch II Hyomandibula Ceratohyal Basihyal Slide 33 Slide 34 Interrelationships The neurocranium, dermatocranium and splanchnocranium eventually becomes intimately associated to form one single, firm skull Slide 35 Key Point Describe the origin of jaws from this picture Slide 36 Key Point The three main components of the cranium are: