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lecture - PowerPoint Presentatio by pengxiuhui

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									Anatomy of Skeletal Elements
              Bone Surface Markings
•   Foramen = opening (arteries, nerves)
•   Fossa = shallow depression
•   Sulcus = shallow groove (artery or nerve)
•   Canal = longer, tubelike opening
•   Fissure = narrow, cleftlike opening
•   Notch = indentation at the end of a bone
•   Meatus = type of canal
•   Condyle = large, round protuberance, attachment of muscles
•   Epicondyle = above or upon a condyle
•   Facet = smooth flat articular surface
•   Trochanter = very large projection
•   Tuberosity = large, rounded, roughened projection
•   Tubercle = rounded eminence/elevation
•   Crest = roughened border or ridge
•   Spine = sharply pointed projection
          Skeletal system includes
• Axial division
  – Skull and associated bones
     • Auditory ossicles
     • Hyoid bones
  – Vertebral column
  – Thoracic cage
     • Ribs sternum

    • Appendicular division
       -Pectoral girdle
       -Pelvic girdle
                   The Axial Skeleton
• Axial division
   – Skull and associated bones
      • Auditory ossicles
      • Hyoid bones
   – Vertebral column
   – Thoracic cage
      • Ribs sternum
The Skull and Associated Bones
                      Sutures
• Immovable joints (synarthrotic, fibrous joints)
• Form boundaries between skull bones
• Five sutures
  –   Coronal
  –   Sagittal
  –   Lambdoid
  –   Squamous
  –   Frontonasal
                        The Adult Skull
•skull = 22 bones
•cranium = 8 bones: frontal, occipital, 2 temporals, 2 parietals, sphenoid and
         ethmoid
•facial bones = 14 bones: nasals, maxillae, zygomatics, mandible, lacrimals,
         palatines, inferior nasal conchae, vomer.
•skull forms a larger cranial cavity
         -also forms the nasal cavity, the orbits, paranasal sinuses
         mandible and auditory ossicles are the only movable skull bones

•cranial bones also: attach to membranes called meninges
                 -stabilize positions of the brain, blood vessels
                 -outer surface provides large areas for muscle attachment that
                 move the head or provide facial expressions
Figure 6.4 Sectional Anatomy of
         the Skull, Part I
• Frontal bone
  – Forms the forehead
  – Roof of the orbit
  – articulates with
    parietal, sphenoid,
    lacrimal, nasal,
    ethmoid, zygomatic
    and maxilla
  – superior and lateral to
    glabellar region –
    frontal sinuses
  – inferior portion –
    supraorbital ridges
    with supraorbital
    notch (supraorbital
    nerve and artery)
•Parietal bones
   -Part of the superior and lateral surfaces of the cranium
   -articulate with each other – sagittal suture
   -articulate with occipital, frontal,
   temporal and sphenoid bones
•Temporal bone
    -Forms wall of jugular foramen
    -Petrous part: posterior portion
    -Tympanic part: associated with ear canal
    -Squamous part: anterior portion, fan-shaped
        -zygomatic process
        -forms cranial portion of the TMJ joint
        -inferior to zygo. process – mandibular fossa (mandibular condyle)
•Temporal bone – petrous portion
    •houses the inner ear
    -inferior aspect – mastoid process
    (air spaces that communicate with the
    middle
    ear)
         -also for attachment of
    sternocleidomastoid muscle
    -inferior to mastoid process –
    mastoid foramen
    -anterior to mastoid process –
    external acoustic meatus
    -inferior and medial to the MP –
    styloid process (muscle attachment)
         -stylomastoid foramen (7th
    cranial)
• Occipital bone
      • Part of the base of the skull
      • articulates with parietal, temporal
        and sphenoid
      • Surrounds the foramen magnum
      • lateral to the FM – hypoglossal
        canal (12th cranial)
      • projections = occipital condyles
      • Forms part of the jugular foramen
• Sphenoid bone
  – Contributes to floor of
    cranium
  – articulates with the frontal,
    ethmoid, temporal
    zygomatic, parietal
    maxillary, palatine, vomer
    & occipital bones
  – Bridges cranial and facial
    bones
  – Optic canal allows passage
    of optic nerve
                                     -Foramina:
                                              -superior orbital fissure – 3rd, 4th, 6th cranials
                                              -foramen ovale – 5th cranial (mandibular)
                                              -foramen rontundum – 5th cranial
                                              -foramen spinosum – middle meningeal artery
                                              -optic canal




-greater wing – posterolateral portion
-lesser wing
-Pterygoid processes – inferior to the
greater wings – sites of muscle
attachment
     -lateral and medial plates with a
     fossa located between
-body: sella turcica, tuberculum
sellae, dorsum sellae, sphenoid
Ethmoid bone   –
               –
                 Irregularly shaped bone
                 Forms part of orbital wall
               – Forms roof of nasal cavity
               – articulates with: frontal, sphenoid,
                 lacrimal and maxillary bones
               – connects with the vomer
               – two lateral masses – contain the
                 ethmoid sinuses
                   • projections called the superior and
                     middle nasal conchae
               – two plates: perpendicular plate
               & the cribiform plate
               – Cribiform plate: perforations for
                 olfactory nerve, midline is the crista
                 galli
               – Perpendicular plate = upper part
                 of nasal septum
                   14 Facial Bones




Nasal (2)                    Maxillae (2)   Zygomatic (2)
Mandible (1)                 Lacrimal (2)   Palatine (2)
Inferior nasal conchae (2)                  Vomer (1)
                 Bones of the Face
• Maxillae
  – Paired bone
  – Largest of facial
    bones
  – Form upper jaw
  – body = orbital, nasal,
    infratemporal and
    facial surfaces
  – body contains the
    maxillary sinuses
          Maxillary bones: Anterior View




• frontal process – articulates with frontal bone and nasal bones & forms medial
  orbital rim
• facial surface – body of maxilla
    – infraorbital foramen – landmark for local
    – inferior to this IF – canine fossa
    – inferior portion of the maxilla – alveolar processes of the teeth (contains the roots of
      the maxillary teeth
                       • Inferior view:
• zygomatic process:      – palatine process – major portion of
                            the hard palate
  articulates with        – joined by the median palatine
  zygomatic bone            suture covered by the median
                            palatine raphe (fibrous tissue)
                          – anterior portion – incisive foramen
                            (nasopalatine nerves and vessels)
              Zygomatic Bones




• Cheekbones
• Lateral wall of orbit along with sphenoid
• Part of zygomatic arch along with part of temporal
• Palatine bones
   –   Small, L-shaped
   –   link between maxilla and sphenoid
   –   Form posterior portion of hard palate
   –   Contribute to floor of orbit
   –   made up of horizontal plate and a vertical plate +
       orbital process
   -midpoint of horizontal plate = nasal crest
   -vertical plates – forms lateral wall of
   nasal cavity




-two foramina in each palatine bone
         1. greater palatine – about 3rd molar
           -greater palatine nerve, landmark
            for administration of local
         2. lesser palatine – lesser palatine
                   nerve to soft palate
• Inferior nasal concha
   – Located on each side of nasal septum
   – Increase epithelial surface
   – Create turbulence in inspired air




• Lacrimal bones
   – Smallest bones in skull
   – Forms nasolacrimal groove leading to nasolacrimal canal
   – Delivers tears to nasal cavity
               Palatine & Vomer




• Vomer
  – posterior part of nasal septum
  – Forms inferior portion of nasal septum
  – Articulates with maxillae and palatines
                Mandible
• lower jaw
• only freely movable bone of the skull
• moving articulations with temporal bone
Mandible: Anterior surface
• many landmarks on the
  body
  – mental protruberence –
    beneath the roots of the
    mandibular incisors
  – faint ridge at the midline –
    mandibular symphysis
    (fusion of right and left
    processes during
    development)
  – lateral to the midline –
    mental foramina (mental
    nerve and vessels into the
    mandibular canal)
     Mandible: Anterior &
      Lateral surfaces

•   superior to the body – alveolar
    processes of the mandible
•   body is capable of elongation in
    children
•   like the maxillary alveolar processes,
    the alveolar processes of the mandible
    can become completely resorbed upon
    loss of teeth
•   ramus – superior and posterior to the
    body
     – primary area for attachment of muscles
       for mastication
     – also grows
     – anterior border is the coronoid process
     – posterior border – mandibular condyle
     – between in the mandibular notch or
       coronoid notch (landmark for local)
     – ramus and body joined at the external
       oblique line
     – superior to this – coronoid notch
                                                Mandible: Inferior
                                                    surface

-visible are the genial tubercles – or mental spines
          -muscle attachment area
-two fossas: 1) sublingual (sublingual salivary gl.)
          2) submandibular (submandibular gl.)
   -divided by the mylohyoid line (mylohyoid m.)
-mandibular foramen – opening of the mandibular canal
          -for the exit of the alveolar nerve and vessels
          -can be lost with alveolar process reabsorption
          -overhanging the foramen – lingula (attachment of sphenomandibular
          ligament – TMJ)
                The Hyoid Bone
• Suspended by stylohyoid ligaments
• Consists of a body, greater horns and lesser
  horns
• Base for muscles of the tongue and larynx
   The Orbital and Nasal Complexes
• Orbital complex
  – Bony recess that holds the eye
  – Seven bones
     •   Frontal bone
     •   Lacrimal bones
     •   Palatine bones
     •   Zygomatic bones
     •   Ethmoid
     •   Sphenoid
     •   Maxillae
    Orbital Complex: Eye socket
•   medial wall: frontal process, lacrimal bone and part of
    ethmoid
• lateral wall: sphenoid, zygomatic
• floor: maxillary, zygomatic
• back: sphenoid + superior orbital
fissure
-top: frontal bone
• sphenoid and frontal bones
are separated by the infaorbital
fissure (infraorbital & zygomatic
nerves, infraorbital artery
and inferior opthalmic vein)
    -continues on as the infraorbital sulcus
    -becomes the infraorbital canal
    -terminates on the facial surface as the
    infraorbital foramen (infraorbital nerve)
• Bones and           The Nasal Complex
  cartilage that
  enclose the nasal
  cavity
                  Nasal bones & cavities
• Nasal bones
   – Paired bones – forms the bridge
   – Articulate with frontal bone
   – nasion: junction between frontal and nasal bones
• Nasal cavity
   – anterior, triangular opening: piriform aperture
   -lateral wall: nasal conchae (superior, middle, inferior)
   -superior and middle - ethmoid
   -inferior nasal conchae – separate bone
   -divided into separate cavities – nasal septum
       -anterior portion is nasal septal cartilage
       -superior portion formed by perpendicular plate
       -inferior portion formed by the vomer


        deviated nasal septum: nasal septum divides the nasal cavity into right and left
                  halves
                  -three components: vomer, septal cartilage & perpendicular plate of the
                  ethmoid
                  -deviation results in a later deflection of the septum
                  -severe deviation may affect breathing
                          Paranasal Sinuses
                                                         • part of the nasal complex
                                                         • Paired cavities in ethmoid,
                                                           sphenoid, frontal and maxillary
                                                         • Lined with mucous membranes
                                                           and open into nasal cavity
                                                           though openings called ostia
                                                         • Resonating chambers for voice,
                                                           lighten the skull
                                                         • Sinusitis is inflammation of the
                                                           membrane (allergy)
•   frontal sinuses: frontal bone, separated by a septum • infection can easily spread from
      – connects with nasal cavity – frontonasal duct      one sinus to the other through
•   sphenoid sinuses: body of the sphenoid bone            the nasal cavity
      – also drain into nasal cavity                     • can also spread to other tissues
•   ethmoid sinuses: or ethmoid air cells, located in the    – secondary sinusitis
    lateral masses
     – anterior, middle and posterior sinuses
•   maxillary: body of the maxilla
     – size varies with individual and age
     – largest of the sinuses
     – close proximity to alveolar processes – periodontal
       tissues may be in direct contact with sinus’ mucus
       membranes
                        Cranial Fossae

• Depressions in cranial
  floor
• Anterior cranial fossa
   – Frontal bone, ethmoid,
     lesser wings of
     sphenoid
• Middle cranial fossa
   – Sphenoid, temporal
     bones, parietal bones
• Posterior cranial fossa
   – Occipital bone,
     temporal bones,
     parietal bones
Cranial Fossae
     The Vertebral Column


http://www.wisc-online.com/objects/index.asp?objID=AP12104
             Adult Vertebral Column

• 26 vertebrae
    – 24 individual vertebrae
    – Sacrum
    – Coccyx
•   Seven cervical vertebrae
•   Twelve thoracic vertebrae
•   Five lumbar vertebrae
•   Sacrum and coccyx are fused
Typical Vertebrae   • Body
                      – weight bearing
                    • Vertebral arch
                      – pedicles
                      – laminae
                    • Vertebral foramen
                    • Seven processes
                      – 2 transverse
                      – 1 spinous
                      – 4 articular
                    • Vertebral notches
Typical Cervical Vertebrae (C3-C7)

                  • Smaller bodies
                  • Larger spinal canal
                  • Transverse processes
                     – shorter
                     – transverse foramen
                       for vertebral artery
                  • Spinous processes of
                    C2 to C6 often bifid
                  • 1st and 2nd cervical
                    vertebrae are unique
                     – atlas & axis
               Atlas & Axis (C1-C2)




• Atlas -- ring of bone, superior facets for occipital condyles
   – nodding movement at atlanto-occipital joint signifies “yes”
• Axis -- dens or odontoid process is body of atlas
   – pivotal movement at atlanto-axial joint signifies “no”
Thoracic Vertebrae
    (T1-T12)
• Larger and stronger bodies
• Longer transverse &
  spinous processes
• Facets or demifacets on
  body for head of rib
• Facets on transverse
  processes (T1-T10) for
  tubercle of rib
                 Lumbar Vertebrae

• Strongest & largest
• Short thick spinous &
  transverse processes
   – back musculature
Intervertebral Foramen & Spinal Canal




  • Spinal canal is all vertebral foramen together
  • Intervertebral foramen are 2 vertebral notches together
Herniated discs:
•distortion in the
intervertebral discs
between vertebral bodies
•bulges out into the
intervertebral foramen
•presses on spinal nerves
which pass through this
foramen
•pain, numbness, paralysis

								
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