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Chapter 7: The Axial Skeleton - Coggle Diagram

- - - - Calvaria
        Cranial vault; skullcap
        
        Forms superior, lateral, posterior & forehead aspects of the skull
      - Cranial Base
        
        Inferior part
        
        Divided into 3 "steps" or fossae: anterior, middle & posterior cranial fossae
      - Cranial Bones
        
        8 large bones
        
        Paired: parietal & temporal
        
        Unpaired: frontal, occipital, sphenoid & ethmoid bones
        
        Paired Bones
        
        Temporal Bones
        
        Inferior to parietal bones
        
        Form inferolateral region of the skull & parts of cranial floor
        
        Specific Parts of Temporal Bone
        
        Squamous
        
        Plate-shaped
        
        Abuts the squamous suture
        
        Has a barlike zygomatic process that projects anteriorly to meet the zygomatic bone of the face
        
        Forms the zygomatic arch (cheekbone)
        
        Mandibular fossa on the inferior surface of the zygomatic process receive the condylar process of the mandible
        
        Zygomatic Process
        
        Projects anteriorly to meet the zygomatic bone of the face
        
        Forms the zygomatic arch (cheekbones)
        
        Mandibular Fossa
        
        Oval
        
        On the inferior surface of the zygomatic process
        
        Receives the condylar processes of the mandible
        
        Forms the freely movable temporomandibular joint
        
        Tympanic
        
        Surrounds the external acoustic meatus
        
        External Acoustic Meatus
        External Ear Canal
        
        Sound enters the ear through this canal
        
        External acoustic meatus & tympanic membrane (eardrum) are parts of the external ear
        
        Petrous
        
        Contributes to the cranial base
        
        Forms a bony wedge between occipital bone (posteriorly) & sphenoid bone (anteriorly)
        
        Looks like mountain ridge within the cranial cavity
        
        Posterior slop lies in posterior cranial fossa
        
        Anterior slope is in the middle cranial fossa
        
        Houses the temporal lobes of brain
        
        Middle & Inner Ear Cavities
        
        Housed inside the petrous part of temporal bone
        
        Contain the sensory apparatus for hearing & balance
        
        Styloid Process
        
        Projects inferiorly
        
        Attachment point for some muscles of the tongue, pharynx & a ligament that connects the skull to hyoid bone of the neck
        
        Mastoid Process
        
        Lateral & posterior to the styloid process
        
        Anchoring site for some neck muscles
        
        Fill of air sinuses (mastoid air cells)
        
        Parietal Bones
        
        Form most of the superior part of the skull & its lateral walls
        
        Parietal bones articulate with other cranial bones at the 4 largest sutures
        
        Unpaired Bones
        
        Frontal Bone
        
        Forms forehead & roofs of the orbits
        
        Protrudes slightly above the orbits to form superciliary arches (deep to eyebrows)
        
        Contributes to the anterior cranial fossa
        
        Holds large frontal lobes of brain
        
        Glabella
        
        Smooth part of the frontal bone medial to the eyebrows
        
        Inferior to glabella is where the frontal bone meets the nasal bones at frontonasal suture
        
        Regions of the frontal bone lateral to the labella contain air-filled frontal sinuses
        
        Supraorbital Margin
        
        Pierced by a hole/notch: supraorbital foramen/notch
        
        Occipital Bone
        
        Makes up the posterior part of the cranium & cranial base
        
        Internally, forms the walls of the posterior cranial fossa
        
        Holds the cerebellum
        
        Articulates w/ parietal bones at the lambdoid suture & with the temporal bones at the occipitomastoid suture
        
        Features on External Surface of Occipital Bone
        
        External Occipital Protuberance
        Knob in the midline, at then junction of the base & posterior wall of skull
        
        Foramen Magnum
        Large hole
        
        At base of occipital bone
        
        Inferior part of the brain connects with the spinal cord through this whole
        
        Flanked laterally by 2 occipital condyles
        
        Occipital Condyles
        
        Articulate with the 1st vertebra of the vertebral column
        
        Allows the head to nod "yes"
        
        1 more item...
        
        Sphenoid Bone
        
        Spans width of the cranial floor
        
        Resembles a bat with spread out wings
        
        Articulates with every other cranial bone
        
        Consists of a central body & 3 pairs of processes
        
        Central Body
        
        Sella Turcica
        
        On superior surface of the sphenoid body
        
        Seat of saddle (hypophyseal fossa) holds the pituitary gland
        
        Optic Canal
        
        Lies just anterior to the sella turcica
        
        Option nerve passes through this hole from the orbit into the cranial cavity
        
        Sphenoidal Sinuses
        
        Paired
        
        The greater wings project laterally from the sphenoid body
        
        Form parts of the middle cranial fossa & orbit
        
        Ethmoid Bone
        
        Most deeply situated bone of the skull
        
        Lies anterior to the sphenoid bone & posterior to the nasal bone
        
        Form most of the medial bony area between the nasal cavity & orbitals
        
        Cribriform Plates
        
        Superior surface of ethmoid bone
        
        Contributes to the roof of the nasal cavities & the floor of anterior cranial fossa
        
        Contains cribriform foramina
        
        Cribriform Foramina
        
        Olfactory nerve pass through these foramina as they run from nasal cavity to the brain
        
        Crista Galli
        
        Superior projection between the 2 cribriform plates
        
        Fibrous membrane (falx cerebri) attaches to crista galli to secure brain in the cranial cavity
        
        Perpendicular Plate
        
        Projects inferiorly in the median plane
        
        Forms the superior part of the nasal septum
        
        Vertical partition that divides the nasal cavity into right & left halves
        
        Superior & Middle Nasal Conchae
        
        Extend medially from the perpendicular plate
        
        Protrude into the nasal cavity
        
        Curved like scrolls
        
        Named after the conch cells found on beaches
    - - Coronal Suture
        
        Runs in coronal plane
        
        Occurs anteriorly where parietal bones meet the frontal bone
      - Squamous Suture
        
        Occurs where each parietal bone meets a temporal bone inferiorly on each lateral aspect of the skull
      - Sagittal Suture
        
        Occurs where the right & left parietal bones meet superiorly in the middle of cranium
      - Lambdoid Suture
        
        Occurs where the parietal bones meet the occipital bone posteriorly
        
        Resembles the Greek letter lambda
    - - Facial Bones
        
        14 Bones
        
        Paired: maxillae, zygomatics, nasals, lacrimals, palatines & inferior nasal conchae
        
        Unpaired: mandible & vomer
        
        Unpaired
        
        Mandible
        
        Lower jawbone
        
        Largest, strongest bone in face
        
        Horizontal body + 2 upright rami
        
        Rami
        Branches
        
        Each ramus meets the horizontal body posteriorly at a mandibular angle
        
        At the superior margin of each ramus are 2 processes
        
        Coronoid Process
        
        Anterior
        
        Flat, triangular projection
        
        Condylar Process
        
        Posterior
        
        Articulates with the temporal bone
        
        Forms the temporomandibular joint
        
        Mandibular Notch
        
        Separates the coronoid & condylar processes
        
        Mandibular Foramen
        
        On the medial surface of each ramus
        
        Where tooth sensation nerve enters the mandibular body supplies the roots of the lower teeth
        
        Horizontal Body
        
        Anchors the lower teeth & forms the chin
        
        Superior border of the horizontal body is the alveolar process
        
        Alveolar Process
        
        Tooth sockets open onto this surface
        
        Mental Foramen
        
        Opens on the anterolateral side of the mandibular body
        
        Transmits blood vessels & nerves to the lower lip & skin of chin
        
        Vomer
        Forms the inferior part of the nasal septum
        
        Inferior Nasal Conchae
        
        Thin, curved bones that project medially from the lateral walls of the nasal cavity
        
        Paired
        
        Maxillary Bones
        Maxillae
        
        Form the upper jaw & central part of the facial skeleton
        
        Keystone bones of the face
        
        Articulate with other facial bones, except mandible
        
        Lines lateral to the nasal cavity & contain the maxillary sinuses
        
        Laterally, the maxillae articulate with the zygomatic bones at the zygomatic processes
        
        Forms the borders of the inferior orbital fissure
        
        Inferior Orbital Fissure
        
        Floor of the orbit
        
        Transmits several vessels & nerves
        
        Maxillary Sinuses
        
        Largest of the paranasal air sinuses
        
        Extend from the orbit down to the roots of the upper teeth
        
        Zygomatic Bones
        Cheek Bones
        Form lateral walls of orbits
        
        Nasal Bones
        Forms bridge of the nose
        
        Lacrimal Bones
        Located in the medial orbital walls
        
        Palatine Bones
        Complete the posterior part of the hard palate
    - - Nasal Cavity
        
        Constructed of bone & cartilage
        
        Roof is the ethmoid's cribriform plates
      - Paranasal Sinuses
        
        The bones surrounding the nasal cavity contain hollow spaces internally
        
        Frontal, ethmoid, sphenoid & both maxillary bones
        
        Air-filled sinuses are called paranasal sinuses
        
        Para = near
        
        Lined by mucous membrane
        
        Help warm, moisten & filter inhaled air
        
        Lighten the skull
        
        Connect to the nasal cavity
      - Orbits
        
        Cone-shaped cavities that hold the eyes, muscles that move the eyes, some fat & tear-producing glands
      - Hyoid Bone
        
        Not really part of the skull
        
        Inferior to the mandible on the anterior neck
        
        Resembles an archer's bow
        
        Only bone with no direct articulation with other bones
        
        Acts as a movable base for the tongue
- - - - T1-T10
        
        Each side of the body of T1-T10 bears demifacets for articulation with ribs
        
        Facets on transverse processes of T1-T10 articulate with the tubercles of the ribs
    - - [Sacrum
        
        Inferior to the lumbar vertebrae
        
        Articulates with the hip bones of the pelvic
        
        Triangular
        
        Shapes the posterior wall of the pelvis
        
        Formed by 5 fused vertebrae (S1-S5)
        
        Articulates superiorly with L5 via a pair of superior articular processes & an intervertebral disc
        
        Articulates inferiorly with coccyx](https://coggle.it/diagram/akTc6m2JQW3pcUgT)
        
        Coccyx
        Tailbone
        
        Most inferior part of the vertebral column
        
        Consists of 3-5 fused vertebrae
        
        Offers only slight support to pelvic organs
        
        Sacral Promontory
        Where S1 bulges into pelvic cavity
        
        Ala
        
        Wings of the sacrum
        
        Develops from fused rib elements
        
        Sacral Foramina
        
        Anterior sacral foramina: passage for ventral rami of sacral spinal nerves
        
        Posterior sacral foramina: passage for dorsal rami of sacral spinal nerves
    - - 4 Curvatures that give the vertebral column its S shape
        
        Concave Posteriorly
        
        Develop during 1st 2 years of childhood
        
        Secondary curvatures
        
        Lumbar Curvature
        
        Develops when the baby begins to walk (~1 yr)
        
        Provides optimal balance during standing
        
        Cervical Curvature
        
        Present before birth, but isn't pronounced until the baby starts to lift its head (3 months)
        
        Convex Posteriorly
        
        Well developed at birth
        
        Primary curvatures
        
        Thoracic Curvature
        
        Sacral Curvature
    - - Major Supporting Ligaments
        
        Anterior Longitudinal Ligaments
        
        Wide
        
        Attaches strongly to both the bony vertebrae & intervertebral discs
        
        Supports & prevents hyperextension of the back
        
        Hyperextension: bending too far backward
        
        Run vertically along the anterior & posterior surfaces of the bodies of the vertebrae
        
        From neck to sacrum
        
        Posterior Longitudinal Ligaments
        
        Narrow
        
        Relatively weak
        
        Attaches only to the intervertebral discs
        
        Helps to prevent hyperflexion
        
        Hyperflexion: bending the veretebral column too sharply forward
    - - Nucleus Pulposus
        
        Gelatinous & acts like a rubber ball
        
        Enables the spine to absorb compressive stress
      - Anulus Fibrosus
        
        ~12 concentric rings
        
        Outer rings consist of ligament
        
        Inner rings consist of fibrocartilage
        
        Main function of the rings is to contain the nucleus pulposus
        
        Limiting its expansion when the spine is compressed
        
        Function of the Rings
        
        Contain the nucleus pulposus
        
        Limiting its expansion when the spine is compressed
        
        Bind the successive vertebrae together
        
        Resist tension on the spine
        
        Absorbing compressive forces
    - - Structure of Typical Vertebrae
        
        Vertebral Arch
        
        Forms the posterior portion of the vertebra
        
        Composed of 2 pedicles & 2 laminae
        
        Protects the spinal cord & spinal nerves located in the vertebral foramen
        
        Pedicles
        
        Short, bony walls that project posteriorly from the vertebral body
        
        Form the sides of the arch
        
        Laminae
        
        Flat, bony plates that complete the arch posteriorly
        
        End from the transverse processes to the spinous process
        
        Vertebral Foramen
        
        Large hole encircled by the body & vertebral arch
        
        Successive vertebral foramina of the articulated vertebrae form the long vertebral canal
        
        Where spinal cord & spinal nerve roots pass
        
        Spinous Process
        
        Median, posterior projection arising at the junction of the 2 laminae
        
        Attachment site for muscles & ligaments that move & stabilize the vertebral column
        
        Transverse Process
        
        Projects laterally from each pedicle-lamina junction
        
        Attachment sites for muscle & ligaments
        
        Articular Processes
        
        Protrude superiorly & inferiorly from the pedicle-lamina junctions
        
        Form movable joints between successive vertebrae
        
        Inferior articular processes of each vertebra join with the superior articular processes of the vertebra immediately inferior
        
        Facets
        Smooth joint surfaces of these processes
        
        Intervertebral Foramina
        
        Lateral openings between adjacent vertebrae
        
        Formed by notches on the superior & inferior borders of the pedicles
        
        Spinal nerves from spinal cord pass through these foramina
        
        Body
        
        Anterior portion of the vertebra
        
        Disc-shaped
        
        Weight-bearing region of the vertebra
      - General Types of Movement Between Vertebrae
        
        Flexion & extension
        
        Bending forward & sitting up straight
        
        Lateral flexion
        
        Bending upper body right/left
        
        Rotation
        
        Vertebrae rotate on one another in the long axis of the vertebral column
    - - Unusual
        
        C1 & C2 are unusual
        
        No intervertebral disc lies between them
        
        Have unique structural & functional features
        
        C1
        Atlas
        
        Lacks a body & spinous process
        
        Ring of bone consisting of anterior & posterior arches & a lateral mass on each side
        
        Superior articular facets receive the occipital condyles of the skull
        
        Participates in flexion & extension of the head and neck
        
        Nod "yes"
        
        Inferior articular facets form joints with axis
        
        C2
        Axis
        
        Has a body, spinous process & other typical vertebral processes
        
        Not as specialized as C1
        
        Has knoblike dens
        
        Dens
        
        Projects superiorly from the body
        
        Acts as a pivot for the rotation of the atlas & skull
        
        Participates in rotating the head from side to side
        
        Shake head "no"
      - Typical
        
        C3-C7
        
        Body is wider laterally
        
        Spinous process is short, projects posteriorly & is bifid
        
        Bifid: split/forked at its tip
        
        Except C7
        
        Vertebral foramen is large & triangular
        
        Each transverse process contains a transverse foramen
        
        Blood vessels pass through
        
        C7
        Vertebra Prominens
        
        Spinous process is not bifid
        
        Larger than the other cervical vertebrae
- - - - Sections
        
        Body
        
        Midportion
        
        Makes up bulk of sternum
        
        Sides of sternal body are notched where it articulates with the costal cartilages of ribs 2-7
        
        Xiphoid Process
        
        Forms inferior end of the sternum
        
        Ossifies ~ 40yrs old
        
        Manubrim
        
        Superior section
        
        Shaped like the knot in a necktie
        
        Clavicular notches articulate with medial end of clavicles
      - Anatomical Landmarks
        
        Jugular Notch
        Suprasternal Notch
        
        Central indentation at superior border of manubrim
        
        Sternal Angle
        
        Horizontal ridge where the manubrim joins the body
        
        Xiphisternal joint
        
        Where sternal body and diploid process fuse
        
        Lies at the level of the 9th thoracic vertebra
    - - True Ribs
        Vertebrosternal
        
        Superior 7 pairs
        
        Attach directly to the sternum by their costal cartilages
      - False Ribs
        
        Inferior 5 pairs (8-12)
        
        Attach indirectly to sternum, or not at all
        
        8-10 attach to sternum directly
        
        Vertebrochondral ribs
        
        11 & 12 have no anterior attachments
        
        Floating ribs
        
        Vertebral ribs