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Key Terms

  • Page ID
    20214
  • alveolar process of the mandible
    upper border of mandibular body that contains the lower teeth
    alveolar process of the maxilla
    curved, inferior margin of the maxilla that supports and anchors the upper teeth
    angle of the mandible
    rounded corner located at outside margin of the body and ramus junction
    angle of the rib
    portion of rib with greatest curvature; together, the rib angles form the most posterior extent of the thoracic cage
    anterior (ventral) sacral foramen
    one of the series of paired openings located on the anterior (ventral) side of the sacrum
    anterior arch
    anterior portion of the ring-like C1 (atlas) vertebra
    anterior cranial fossa
    shallowest and most anterior cranial fossa of the cranial base that extends from the frontal bone to the lesser wing of the sphenoid bone
    anterior longitudinal ligament
    ligament that runs the length of the vertebral column, uniting the anterior aspects of the vertebral bodies
    anulus fibrosus
    tough, fibrous outer portion of an intervertebral disc, which is strongly anchored to the bodies of the adjacent vertebrae
    appendicular skeleton
    all bones of the upper and lower limbs, plus the girdle bones that attach each limb to the axial skeleton
    articular tubercle
    smooth ridge located on the inferior skull, immediately anterior to the mandibular fossa
    atlas
    first cervical (C1) vertebra
    axial skeleton
    central, vertical axis of the body, including the skull, vertebral column, and thoracic cage
    axis
    second cervical (C2) vertebra
    body of the rib
    shaft portion of a rib
    brain case
    portion of the skull that contains and protects the brain, consisting of the eight bones that form the cranial base and rounded upper skull
    calvaria
    (also, skullcap) rounded top of the skull
    carotid canal
    zig-zag tunnel providing passage through the base of the skull for the internal carotid artery to the brain; begins anteromedial to the styloid process and terminates in the middle cranial cavity, near the posterior-lateral base of the sella turcica
    cervical curve
    posteriorly concave curvature of the cervical vertebral column region; a secondary curve of the vertebral column
    cervical vertebrae
    seven vertebrae numbered as C1–C7 that are located in the neck region of the vertebral column
    clavicular notch
    paired notches located on the superior-lateral sides of the sternal manubrium, for articulation with the clavicle
    coccyx
    small bone located at inferior end of the adult vertebral column that is formed by the fusion of four coccygeal vertebrae; also referred to as the “tailbone”
    condylar process of the mandible
    thickened upward projection from posterior margin of mandibular ramus
    condyle
    oval-shaped process located at the top of the condylar process of the mandible
    coronal suture
    joint that unites the frontal bone to the right and left parietal bones across the top of the skull
    coronoid process of the mandible
    flattened upward projection from the anterior margin of the mandibular ramus
    costal cartilage
    hyaline cartilage structure attached to the anterior end of each rib that provides for either direct or indirect attachment of most ribs to the sternum
    costal facet
    site on the lateral sides of a thoracic vertebra for articulation with the head of a rib
    costal groove
    shallow groove along the inferior margin of a rib that provides passage for blood vessels and a nerve
    cranial cavity
    interior space of the skull that houses the brain
    cranium
    skull
    cribriform plate
    small, flattened areas with numerous small openings, located to either side of the midline in the floor of the anterior cranial fossa; formed by the ethmoid bone
    crista galli
    small upward projection located at the midline in the floor of the anterior cranial fossa; formed by the ethmoid bone
    dens
    bony projection (odontoid process) that extends upward from the body of the C2 (axis) vertebra
    ear ossicles
    three small bones located in the middle ear cavity that serve to transmit sound vibrations to the inner ear
    ethmoid air cell
    one of several small, air-filled spaces located within the lateral sides of the ethmoid bone, between the orbit and upper nasal cavity
    ethmoid bone
    unpaired bone that forms the roof and upper, lateral walls of the nasal cavity, portions of the floor of the anterior cranial fossa and medial wall of orbit, and the upper portion of the nasal septum
    external acoustic meatus
    ear canal opening located on the lateral side of the skull
    external occipital protuberance
    small bump located at the midline on the posterior skull
    facet
    small, flattened area on a bone for an articulation (joint) with another bone, or for muscle attachment
    facial bones
    fourteen bones that support the facial structures and form the upper and lower jaws and the hard palate
    false ribs
    vertebrochondral ribs 8–12 whose costal cartilage either attaches indirectly to the sternum via the costal cartilage of the next higher rib or does not attach to the sternum at all
    floating ribs
    vertebral ribs 11–12 that do not attach to the sternum or to the costal cartilage of another rib
    fontanelle
    expanded area of fibrous connective tissue that separates the brain case bones of the skull prior to birth and during the first year after birth
    foramen lacerum
    irregular opening in the base of the skull, located inferior to the exit of carotid canal
    foramen magnum
    large opening in the occipital bone of the skull through which the spinal cord emerges and the vertebral arteries enter the cranium
    foramen ovale of the middle cranial fossa
    oval-shaped opening in the floor of the middle cranial fossa
    foramen rotundum
    round opening in the floor of the middle cranial fossa, located between the superior orbital fissure and foramen ovale
    foramen spinosum
    small opening in the floor of the middle cranial fossa, located lateral to the foramen ovale
    frontal bone
    unpaired bone that forms forehead, roof of orbit, and floor of anterior cranial fossa
    frontal sinus
    air-filled space within the frontal bone; most anterior of the paranasal sinuses
    glabella
    slight depression of frontal bone, located at the midline between the eyebrows
    greater wings of sphenoid bone
    lateral projections of the sphenoid bone that form the anterior wall of the middle cranial fossa and an area of the lateral skull
    hard palate
    bony structure that forms the roof of the mouth and floor of the nasal cavity, formed by the palatine process of the maxillary bones and the horizontal plate of the palatine bones
    head of the rib
    posterior end of a rib that articulates with the bodies of thoracic vertebrae
    horizontal plate
    medial extension from the palatine bone that forms the posterior quarter of the hard palate
    hyoid bone
    small, U-shaped bone located in upper neck that does not contact any other bone
    hypoglossal canal
    paired openings that pass anteriorly from the anterior-lateral margins of the foramen magnum deep to the occipital condyles
    hypophyseal (pituitary) fossa
    shallow depression on top of the sella turcica that houses the pituitary (hypophyseal) gland
    inferior articular process
    bony process that extends downward from the vertebral arch of a vertebra that articulates with the superior articular process of the next lower vertebra
    inferior nasal concha
    one of the paired bones that project from the lateral walls of the nasal cavity to form the largest and most inferior of the nasal conchae
    infraorbital foramen
    opening located on anterior skull, below the orbit
    infratemporal fossa
    space on lateral side of skull, below the level of the zygomatic arch and deep (medial) to the ramus of the mandible
    internal acoustic meatus
    opening into petrous ridge, located on the lateral wall of the posterior cranial fossa
    intervertebral disc
    structure located between the bodies of adjacent vertebrae that strongly joins the vertebrae; provides padding, weight bearing ability, and enables vertebral column movements
    intervertebral foramen
    opening located between adjacent vertebrae for exit of a spinal nerve
    jugular (suprasternal) notch
    shallow notch located on superior surface of sternal manubrium
    jugular foramen
    irregularly shaped opening located in the lateral floor of the posterior cranial cavity
    kyphosis
    (also, humpback or hunchback) excessive posterior curvature of the thoracic vertebral column region
    lacrimal bone
    paired bones that contribute to the anterior-medial wall of each orbit
    lacrimal fossa
    shallow depression in the anterior-medial wall of the orbit, formed by the lacrimal bone that gives rise to the nasolacrimal canal
    lambdoid suture
    inverted V-shaped joint that unites the occipital bone to the right and left parietal bones on the posterior skull
    lamina
    portion of the vertebral arch on each vertebra that extends between the transverse and spinous process
    lateral pterygoid plate
    paired, flattened bony projections of the sphenoid bone located on the inferior skull, lateral to the medial pterygoid plate
    lateral sacral crest
    paired irregular ridges running down the lateral sides of the posterior sacrum that was formed by the fusion of the transverse processes from the five sacral vertebrae
    lesser wings of the sphenoid bone
    lateral extensions of the sphenoid bone that form the bony lip separating the anterior and middle cranial fossae
    ligamentum flavum
    series of short ligaments that unite the lamina of adjacent vertebrae
    lingula
    small flap of bone located on the inner (medial) surface of mandibular ramus, next to the mandibular foramen
    lordosis
    (also, swayback) excessive anterior curvature of the lumbar vertebral column region
    lumbar curve
    posteriorly concave curvature of the lumbar vertebral column region; a secondary curve of the vertebral column
    lumbar vertebrae
    five vertebrae numbered as L1–L5 that are located in lumbar region (lower back) of the vertebral column
    mandible
    unpaired bone that forms the lower jaw bone; the only moveable bone of the skull
    mandibular foramen
    opening located on the inner (medial) surface of the mandibular ramus
    mandibular fossa
    oval depression located on the inferior surface of the skull
    mandibular notch
    large U-shaped notch located between the condylar process and coronoid process of the mandible
    manubrium
    expanded, superior portion of the sternum
    mastoid process
    large bony prominence on the inferior, lateral skull, just behind the earlobe
    maxillary bone
    (also, maxilla) paired bones that form the upper jaw and anterior portion of the hard palate
    maxillary sinus
    air-filled space located with each maxillary bone; largest of the paranasal sinuses
    medial pterygoid plate
    paired, flattened bony projections of the sphenoid bone located on the inferior skull medial to the lateral pterygoid plate; form the posterior portion of the nasal cavity lateral wall
    median sacral crest
    irregular ridge running down the midline of the posterior sacrum that was formed from the fusion of the spinous processes of the five sacral vertebrae
    mental foramen
    opening located on the anterior-lateral side of the mandibular body
    mental protuberance
    inferior margin of anterior mandible that forms the chin
    middle cranial fossa
    centrally located cranial fossa that extends from the lesser wings of the sphenoid bone to the petrous ridge
    middle nasal concha
    nasal concha formed by the ethmoid bone that is located between the superior and inferior conchae
    mylohyoid line
    bony ridge located along the inner (medial) surface of the mandibular body
    nasal bone
    paired bones that form the base of the nose
    nasal cavity
    opening through skull for passage of air
    nasal conchae
    curved bony plates that project from the lateral walls of the nasal cavity; include the superior and middle nasal conchae, which are parts of the ethmoid bone, and the independent inferior nasal conchae bone
    nasal septum
    flat, midline structure that divides the nasal cavity into halves, formed by the perpendicular plate of the ethmoid bone, vomer bone, and septal cartilage
    nasolacrimal canal
    passage for drainage of tears that extends downward from the medial-anterior orbit to the nasal cavity, terminating behind the inferior nasal conchae
    neck of the rib
    narrowed region of a rib, next to the rib head
    notochord
    rod-like structure along dorsal side of the early embryo; largely disappears during later development but does contribute to formation of the intervertebral discs
    nuchal ligament
    expanded portion of the supraspinous ligament within the posterior neck; interconnects the spinous processes of the cervical vertebrae and attaches to the base of the skull
    nucleus pulposus
    gel-like central region of an intervertebral disc; provides for padding, weight-bearing, and movement between adjacent vertebrae
    occipital bone
    unpaired bone that forms the posterior portions of the brain case and base of the skull
    occipital condyle
    paired, oval-shaped bony knobs located on the inferior skull, to either side of the foramen magnum
    optic canal
    opening spanning between middle cranial fossa and posterior orbit
    orbit
    bony socket that contains the eyeball and associated muscles
    palatine bone
    paired bones that form the posterior quarter of the hard palate and a small area in floor of the orbit
    palatine process
    medial projection from the maxilla bone that forms the anterior three quarters of the hard palate
    paranasal sinuses
    cavities within the skull that are connected to the conchae that serve to warm and humidify incoming air, produce mucus, and lighten the weight of the skull; consist of frontal, maxillary, sphenoidal, and ethmoidal sinuses
    parietal bone
    paired bones that form the upper, lateral sides of the skull
    pedicle
    portion of the vertebral arch that extends from the vertebral body to the transverse process
    perpendicular plate of the ethmoid bone
    downward, midline extension of the ethmoid bone that forms the superior portion of the nasal septum
    petrous ridge
    petrous portion of the temporal bone that forms a large, triangular ridge in the floor of the cranial cavity, separating the middle and posterior cranial fossae; houses the middle and inner ear structures
    posterior (dorsal) sacral foramen
    one of the series of paired openings located on the posterior (dorsal) side of the sacrum
    posterior arch
    posterior portion of the ring-like C1 (atlas) vertebra
    posterior cranial fossa
    deepest and most posterior cranial fossa; extends from the petrous ridge to the occipital bone
    posterior longitudinal ligament
    ligament that runs the length of the vertebral column, uniting the posterior sides of the vertebral bodies
    primary curve
    anteriorly concave curvatures of the thoracic and sacrococcygeal regions that are retained from the original fetal curvature of the vertebral column
    pterion
    H-shaped suture junction region that unites the frontal, parietal, temporal, and sphenoid bones on the lateral side of the skull
    ramus of the mandible
    vertical portion of the mandible
    ribs
    thin, curved bones of the chest wall
    sacral canal
    bony tunnel that runs through the sacrum
    sacral foramina
    series of paired openings for nerve exit located on both the anterior (ventral) and posterior (dorsal) aspects of the sacrum
    sacral hiatus
    inferior opening and termination of the sacral canal
    sacral promontory
    anterior lip of the base (superior end) of the sacrum
    sacrococcygeal curve
    anteriorly concave curvature formed by the sacrum and coccyx; a primary curve of the vertebral column
    sacrum
    single bone located near the inferior end of the adult vertebral column that is formed by the fusion of five sacral vertebrae; forms the posterior portion of the pelvis
    sagittal suture
    joint that unites the right and left parietal bones at the midline along the top of the skull
    sclerotome
    medial portion of a somite consisting of mesenchyme tissue that will give rise to bone, cartilage, and fibrous connective tissues
    scoliosis
    abnormal lateral curvature of the vertebral column
    secondary curve
    posteriorly concave curvatures of the cervical and lumbar regions of the vertebral column that develop after the time of birth
    sella turcica
    elevated area of sphenoid bone located at midline of the middle cranial fossa
    septal cartilage
    flat cartilage structure that forms the anterior portion of the nasal septum
    skeleton
    bones of the body
    skull
    bony structure that forms the head, face, and jaws, and protects the brain; consists of 22 bones
    somite
    one of the paired, repeating blocks of tissue located on either side of the notochord in the early embryo
    sphenoid bone
    unpaired bone that forms the central base of skull
    sphenoid sinus
    air-filled space located within the sphenoid bone; most posterior of the paranasal sinuses
    spinous process
    unpaired bony process that extends posteriorly from the vertebral arch of a vertebra
    squamous suture
    joint that unites the parietal bone to the squamous portion of the temporal bone on the lateral side of the skull
    sternal angle
    junction line between manubrium and body of the sternum and the site for attachment of the second rib to the sternum
    sternum
    flattened bone located at the center of the anterior chest
    styloid process
    downward projecting, elongated bony process located on the inferior aspect of the skull
    stylomastoid foramen
    opening located on inferior skull, between the styloid process and mastoid process
    superior articular process
    bony process that extends upward from the vertebral arch of a vertebra that articulates with the inferior articular process of the next higher vertebra
    superior articular process of the sacrum
    paired processes that extend upward from the sacrum to articulate (join) with the inferior articular processes from the L5 vertebra
    superior nasal concha
    smallest and most superiorly located of the nasal conchae; formed by the ethmoid bone
    superior nuchal line
    paired bony lines on the posterior skull that extend laterally from the external occipital protuberance
    superior orbital fissure
    irregularly shaped opening between the middle cranial fossa and the posterior orbit
    supraorbital foramen
    opening located on anterior skull, at the superior margin of the orbit
    supraorbital margin
    superior margin of the orbit
    supraspinous ligament
    ligament that interconnects the spinous processes of the thoracic and lumbar vertebrae
    suture
    junction line at which adjacent bones of the skull are united by fibrous connective tissue
    temporal bone
    paired bones that form the lateral, inferior portions of the skull, with squamous, mastoid, and petrous portions
    temporal fossa
    shallow space on the lateral side of the skull, above the level of the zygomatic arch
    temporal process of the zygomatic bone
    short extension from the zygomatic bone that forms the anterior portion of the zygomatic arch
    thoracic cage
    consists of 12 pairs of ribs and sternum
    thoracic curve
    anteriorly concave curvature of the thoracic vertebral column region; a primary curve of the vertebral column
    thoracic vertebrae
    twelve vertebrae numbered as T1–T12 that are located in the thoracic region (upper back) of the vertebral column
    transverse foramen
    opening found only in the transverse processes of cervical vertebrae
    transverse process
    paired bony processes that extends laterally from the vertebral arch of a vertebra
    true ribs
    vertebrosternal ribs 1–7 that attach via their costal cartilage directly to the sternum
    tubercle of the rib
    small bump on the posterior side of a rib for articulation with the transverse process of a thoracic vertebra
    vertebra
    individual bone in the neck and back regions of the vertebral column
    vertebral (spinal) canal
    bony passageway within the vertebral column for the spinal cord that is formed by the series of individual vertebral foramina
    vertebral arch
    bony arch formed by the posterior portion of each vertebra that surrounds and protects the spinal cord
    vertebral column
    entire sequence of bones that extend from the skull to the tailbone
    vertebral foramen
    opening associated with each vertebra defined by the vertebral arch that provides passage for the spinal cord
    vomer bone
    unpaired bone that forms the inferior and posterior portions of the nasal septum
    xiphoid process
    small process that forms the inferior tip of the sternum
    zygomatic arch
    elongated, free-standing arch on the lateral skull, formed anteriorly by the temporal process of the zygomatic bone and posteriorly by the zygomatic process of the temporal bone
    zygomatic bone
    cheekbone; paired bones that contribute to the lateral orbit and anterior zygomatic arch
    zygomatic process of the temporal bone
    extension from the temporal bone that forms the posterior portion of the zygomatic arch
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