Skeletal System:Axial Skeleton

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• Skeletal SystemAxial Skeleton

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The Complete Skeleton

• Axial skeleton
• Skull
• Hyoid bone
• Vertebral column
• Thoracic (rib) cage

• Appendicular skeleton
• Limbs
• Girdles

Fig. 7.1
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Superior and Posterior Views of Skull or Cranium
Modified from Fig. 7.2
Modified from Fig. 7.3

• External occipital protuberance
• Ligamentum nuchae Helps keep head erect
• Nuchal lines Neck muscle attachment

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Lateral View of Skull

• External acoustic (auditory) meatus
• Mastoid Process
• Temporal lines (temporalis muscle)
• Zygomatic arch
• Mandible
• Condyle
• Coronoid process

Modified from Fig. 7.4
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Frontal View of Skull
Modified from Fig. 7.8
Modified from Fig. 7.6

• Optic foramen (optic nerve)
• Nasolacrimal canal (tears from eye to nasal
  capsule)

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Inferior View of Skull

• Foramen magnum
• Occipital condyles
• Jugular foramen, carotid canal (foramen)
• Mandibular fossa
• Hard palate - maxilla and palatine

Modified from Fig. 7.12
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Hyoid Bone and Auditory Ossicles

• Hyoid bone
• Unpaired
• No direct bony attachment to skull
• Attachment point for some tongue muscles
• Attachment point for neck muscles that elevate
  larynx during speech and swallowing
• Auditory ossicles
• Incus
• Malleous
• Stapes

Images from Table 7.8
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Vertebra

• Parts
• Body
• Vertebral foramen
• Vertebral arch
• Superior and inferior articular processes
• Transverse Processes
• Articular facets for rib
• Spinous process

Table 7.9
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Vertebral Column

• Regions
• Cervical (7vertebrae)
• Thoracic (12 vertebrae)
• Lumbar (5vertebrae)
• Sacral bone(5 fused)
• Coccygeal bone (4 fused)

Fig. 7.13
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Cervical Vertebrae

• Atlas
• First vertebra
• yes motion
• Axis
• Second vertebra
• Dens or ______________
• no motion

Modified from Fig. 7.17
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Thoracic and Lumbar Vertebrae
Modified from Fig. 7.18
Modified from Fig. 7.19
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Sacrum and Coccyx
Modified from Fig. 7.20
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Thoracic or Rib Cageand Sternum

• Parts
• Thoracic vertebrae
• Ribs (12 pair)
• True or Vertebrosternal
• False
• Sternum (manubrium, body.xyphoid process is
  cartilage)

Modified from Fig. 7.21
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Points to Remember

• Two major components of the human skeleton
• Axial skeleton arranged along the medial axis
• Appendicular skeleton connects to the axial
  skeleton
• Skull consists of
• 22 bones (single and paired)
• 6 auditory ossicles (3 each side) and 1 hyoid
• Vertebral column consists of
• Cervicals (7)
• Thoracics (12)
• Lumbars (5)
• Sacrum (5, fused)
• Coccyx (3-5, fused)
• Rib cage has true (bone) ribs and false
  (cartilage) ribs

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Questions?