CH 7

Flashcards covering the key vocabulary and concepts from the lecture notes on the skeletal system.

Axial Skeleton

Forms the longitudinal axis of the body and includes the skull, thoracic cage, vertebral column, and supplemental cartilages.

Axial Skeleton Functions

Support and protect the brain, spinal cord, and organs in the trunk; provide attachment sites for muscles that adjust the position of the head, neck, and trunk; perform respiratory movements; stabilize or position parts of the appendicular skeleton.

Suture

Joints (articulations) between the skull bones of adults.

Coronal Suture

Attaches frontal to parietal bones.

Squamous Suture

Attaches temporal and parietal bones.

Sagittal Suture

Attaches parietal bones.

Lambdoid Suture

Attaches occipital to parietal bones.

Nasal Bones

Support superior portion of the bridge of the nose; connected to cartilage supporting distal portions of the nose.

Lacrimal Bones

Form part of medial wall of the orbit (eye socket).

Palatine Bones

Form the posterior portion of the hard palate and contribute to the floor of each orbit.

Zygomatic Bones

Forms part of the cheekbone and contribute to the rim and lateral wall of the orbit.

Maxillae

Support the upper teeth and form inferior orbital rim, the upper jaw, lateral margins of the external nares, and most of hard palate.

Inferior Nasal Conchae

Create turbulence in air entering the nasal cavity and increase epithelial surface area to warm and humidify inhaled air.

Vomer

Forms the inferior portion of the bony nasal septum.

Mandible

Forms the lower jaw.

Frontal Bone

Forms the anterior portion of the cranium and roof of the orbits; frontal sinuses secrete mucus that helps flush the nasal cavities.

Sphenoid Bone

Forms part of the floor of the cranium, unites facial and cranial bones, and acts as a cross-brace to strengthen sides of the skull.

Ethmoid Bone

Forms the anteromedial floor of the cranium, the roof of the nasal cavity, and part of nasal septum and medial orbital wall.

Parietal Bones

Form part of the superior and lateral surfaces of the cranium.

Occipital Bone

Contributes to the posterior, lateral, and inferior cranial surfaces. Features the external occipital crest, which is an attachment point for the ligaments that stabilize the vertebrae of the neck.

Temporal Bones

Form part of the lateral wall of the cranium, articulate with the mandible and facial bones, and surround the sense organs of the inner ear. They also include the mastoid process for muscle attachment to rotate or extend the head and the styloid process, attached to ligaments that support the hyoid bone and tendons of several muscles.

External Acoustic Meatus

Canal beginning on the lateral surface of the temporal bone and ends at the tympanic membrane.

Zygomatic Process of the Temporal Bone

Articulates with the temporal process of the zygomatic bone to form the zygomatic arch.

Mandibular Angle

Posterior, inferior corner of the lower jaw.

Mental Protuberance

Attachment site for several facial muscles.

Alveolar Part of Mandible

Surrounds and supports lower teeth,

Alveolar Processes

Projecting ridges of maxillae and mandible that support the upper and lower teeth.

Frontal Sinuses

Hollow spaces in the frontal bone.

Petrous Part of the Temporal Bone

Encloses structures of the inner ear and auditory ossicles in the middle ear.

Internal Acoustic Meatus

Passageway for blood vessels and facial and vestibulocochlear nerves.

Hypoglossal Canal

Passageway for hypoglossal nerves.

Foramen Lacerum

Jagged slit between sphenoid and petrous portion of temporal bone containing hyaline cartilage and small arteries.

Foramen Ovale

Passage for nerves innervating the jaws.

Carotid Canal

Passage for the internal carotid artery.

Stylomastoid Foramen

Posterior to the base of the styloid process, passage for facial nerve.

Jugular Foramen

Located between the occipital and temporal bone that allows passage for the internal jugular vein.

Foramen Magnum

Connects cranial cavity with the vertebral canal and surrounds the connection between the brain and spinal cord.

Mandibular Fossa

On the inferior surface of the temporal bone and the articulation site for temporal bone and mandible.

Occipital Condyles

Articulation site between skull and first cervical vertebra.

Inferior and Superior Nuchal Lines

Intersect at the occipital crest and are attachment sites for muscles and ligaments that stabilize the head over the cervical vertebrae.

Olfactory Foramina

Permit passage of olfactory nerves.

Optic Canals

Permit passage of optic nerves.

Foramen Rotundum

Permit passage of a branch of trigeminal nerve.

Foramen Spinosum

Passage of blood vessels to CNS membranes.

Internal Occipital Crest

Anchors blood vessels and membranes that stabilize the position of the brain.

Optic Canals (Sphenoid)

Passage for optic nerves from eyes to the brain.

Lesser Wings

Extend horizontally anterior to the sella turcica.

Greater Wings

Extend laterally from the body.

Hypophyseal Fossa

Depression in the sella turcica that supports and protects the pituitary gland.

Sella Turcica

Saddle-shaped enclosure.

Sphenoidal Spine

Projection at the posterior, lateral corner of each greater wing.

Body (Sphenoid)

Forms the central axis of the sphenoid.

Sphenoidal Sinuses

Inferior to the sella turcica, hollow spaces on either side of the body.

Pterygoid Processes

Vertical projections on either side of the body, each forming a pair of pterygoid plates that are attachment sites for muscles moving the mandible and soft palate.

Cribriform plate

Forms anteromedial cranial floor and nasal cavity roof.

Crista galli

Bony ridge that projects superior to cribriform plate, attachment point for falx cerebri (membrane that stabilizes the brain)

Ethmoidal labyrinth

Interconnected air-filled cavities that open into the nasal cavity

Perpendicular plate

forms part of the nasal septum

Palatine bone

Forms posterior portion of the hard palate and contributes to the floor of each orbit

Complexes

Collections of facial bones protecting sense organs

Orbital complexes

Form the orbits and each contain an eye

Nasal complex

Surrounds the nasal conchae

Lacrimal fossa

marks location of the lacrimal (tear) gland

Supra-orbital margin

Thickened part of frontal bone that helps protect the eye

Supra-orbital notch

Passageway for blood vessels to eyebrow, eyelids, and frontal sinuses

Lacrimal sulcus

marks location of lacrimal sac

Nasolacrimal canal

Protects lacrimal sac and nasolacrimal duct

Infra-orbital foramen

Sensory nerve path

Zygomaticofacial foramen

Carries sensory nerve that innervates the cheek

Paranasal sinuses

Lighten skull weight , Allow the voice to resonate , Provides extensive area of mucous epithelium

Mandible

Forms the entire lower jaw

Hyoid bone

Supports the larynx. Greater horn (greater cornu) – Attachment for muscles that move the tongue Lesser horn (lesser cornu) – Attachment for hyoid and laryngeal ligaments

Auditory ossicles

Located within each middle ear cavity Play key role in hearing – Conduct vibrations from the tympanic membrane to internal ear

Fontanelles

Allow for cranial growth to keep pace with brain growth in later fetal stages; Ease passage of head through birth canal

anterior fontanelle

Intersection of frontal, sagittal, and coronal sutures Largest fontanelle Commonly called the “soft spot” Persists until about age 2 Covers a major blood vessel • Pulses as heart beats

Sphenoidal fontanelle

Junction of squamous and coronal sutures

Mastoid fontanelle

Junction of squamous and lambdoid sutures

Posterior fontanelle

Junction of lambdoid and sagittal sutures

Articular processes

Extend superiorly and inferiorly to articulate with adjacent vertebrae

Vertebral arch

Forms posterior and lateral margins of the vertebral foramen

Vertebral body

Transfers weight along the axis of the vertebral column

Vertebral foramen

The opening framed by the vertebral body and the vertebral arch

Articular facet

Forms the joint with the adjacent vertebra

Superior articular processes

Articulate with the inferior articular processes of a superior vertebra

Inferior articular processes

Articulate with the superior articular processes of an inferior vertebra

Laminae

Form the “roof” of the vertebral foramen

Pedicles

Form the sides of the vertebral arch

Spinous process

Projects posteriorly from point of fusion of the laminae

Transverse processes

Project laterally from where pedicles join the laminae sites of muscle attachment May articulate with the ribs

The vertebral canal

Formed by the vertebral foramina of successive vertebrae Encloses the spinal cord

Intervertebral discs

Pads of fibrocartilage separating the bodies of adjacent vertebrae

Intervertebral foramina

Spaces formed between successive pedicles Allow passage of nerves and blood vessels

Cervical Vertebrae

Support skull, stabilize relative positions of brain and spinal cord, and allow controlled head movements. Have transverse foramina. Large vertebral foramen

Thoracic Vertebrae

Support weight of head, neck, upper limbs, and chest; articulate with ribs to allow changes in volume of thoracic cage. facets for rib articulations Smaller vertebral foramen

Lumbar Vertebrae

Support weight of head, neck,upper limbs, and trunk. Smallest vertebral foramen

Ligamentum nuchae

Elastic ligament that connects the vertebra prominens to the external occipital crest Acts like a bow string to maintain the cervical curvature without muscular effort

Thoracic cage

Bony support to thoracic cavity walls Protects heart, lungs, thymus, and other thoracic cavity organs Composed of thoracic vertebrae, ribs, and sternum Ribs and sternum form the rib cage

Vertebrosternal ribs

Connect to sternum by individual costal cartilages Also called True ribs

Vertebrochondral ribs (ribs 8–10) Also called false ribs - Ribs 8-12 are called false ribs in general

Connect to sternum by shared costal cartilages

Vertebral ribs (ribs 11 and 12)

No connection to sternum Also known as floating ribs Also called false ribs