The Skull and Axial Skeleton Review Flashcards

Comprehensive vocabulary flashcards covering the anatomy of the skull, vertebral column, and thoracic cage based on lecture materials.

Cranium (Skull)

The skeletal structure of the head that supports the face and protects the brain, subdivided into facial bones and the brain case.

Mandible

The U-shaped lower jaw bone; it is the only moveable bone of the adult skull.

Orbit

The bony socket that houses the eyeball and the muscles that move it or open the upper eyelid.

Supraorbital foramen

A small opening located near the midpoint of the supraorbital margin that provides passage for a sensory nerve to the forehead skin.

Infraorbital foramen

The point of emergence for a sensory nerve supplying the anterior face below the orbit, located on the anterior maxilla.

Nasal septum

The structure dividing the nasal cavity into halves, formed superiorly by the perpendicular plate of the ethmoid bone and inferiorly by the vomer bone.

Inferior nasal concha

An independent bone of the skull that forms a curved bony plate projecting into the nasal cavity space from the lower lateral wall.

Zygomatic arch

The bony bridge on the side of the skull formed by the junction of the temporal process of the zygomatic bone and the zygomatic process of the temporal bone.

Temporal fossa

A shallow space on the lateral side of the brain case above the level of the zygomatic arch.

Infratemporal fossa

A space located below the level of the zygomatic arch and deep to the vertical portion of the mandible.

Calvaria

The rounded top of the skull, also commonly referred to as the skullcap.

Cranial fossae

Three large spaces in the floor of the brain case (anterior, middle, and posterior) that increase in depth and house specific regions of the brain.

Parietal bone

A paired bone that forms most of the upper lateral side of the skull.

Temporal bone

A paired bone forming the lower lateral side of the skull, subdivided into squamous, mastoid, and petrous regions.

Mastoid process

A large bony prominence on the temporal bone just behind the earlobe that serves as a muscle attachment site.

Petrous portion

The prominent, diagonally oriented petrous ridge in the floor of the cranial cavity that houses middle and inner ear structures.

Mandibular fossa

A deep, oval-shaped depression on the external base of the skull where the mandible joins with the temporal bone.

Carotid canal

A zig-zag shaped tunnel in the base of the skull providing passage for a major artery supplying the brain.

Foramen magnum

The large opening in the base of the occipital bone that allows for the passage of the spinal cord.

Occipital condyle

Oval-shaped bony structures on either side of the foramen magnum that form joints with the first cervical vertebra.

Sphenoid bone

A single, complex midline bone of the central skull that joins with almost every other skull bone; often called the keystone bone.

Sella turcica

A Turkish saddle-shaped region of the sphenoid bone located at the midline of the middle cranial fossa.

Hypophyseal (pituitary) fossa

The rounded depression in the floor of the sella turcica that houses the pea-sized pituitary gland.

Ethmoid bone

A single midline bone that forms the roof and lateral walls of the upper nasal cavity and a portion of the anterior cranial cavity floor.

Crista galli

A small upward bony projection at the midline of the ethmoid bone that serves as an attachment point for brain coverings.

Cribriform plate

A flattened area of the ethmoid bone containing olfactory foramina for the passage of nerve branches from the nasal cavity.

Suture

An immobile joint between adjacent bones of the skull united by dense, fibrous connective tissue.

Pterion

An H-shaped suture region uniting the frontal, parietal, temporal, and sphenoid bones; it is considered the weakest part of the skull.

Hard palate

The bony plate forming the roof of the mouth and floor of the nasal cavity, formed by the maxillary and palatine bones.

Lacrimal bone

A small, rectangular bone forming the anterior medial wall of the orbit containing the lacrimal fossa.

Hyoid bone

A small U-shaped bone in the upper neck that does not contact any other bone and serves as a base for the tongue.

Vertebral column

The sequence of 24 vertebrae, plus the sacrum and coccyx, that supports the head/body and protects the spinal cord.

Cervical vertebrae

The seven vertebrae located in the neck region, designated C1–C7.

Thoracic vertebrae

The 12 vertebrae of the chest region (T1–T12) that possess facets for rib attachment.

Lumbar vertebrae

The five vertebrae of the lower back (L1–L5) which are characterized by large, thick bodies to support body weight.

Sacrum

A triangular bone formed by the fusion of five sacral vertebrae.

Coccyx

The tailbone, derived from the fusion of four small coccygeal vertebrae.

Primary curves

The thoracic and sacrococcygeal curvatures of the spine that are retained from the original fetal curvature.

Secondary curves

The cervical and lumbar curvatures of the spine that develop gradually after birth.

Kyphosis

An excessive posterior curvature of the thoracic region of the vertebral column, also known as humpback.

Lordosis

An excessive anterior curvature of the lumbar region of the vertebral column, also known as swayback.

Scoliosis

An abnormal lateral curvature accompanied by twisting of the vertebral column.

Vertebral foramen

The large opening between the vertebral arch and the body through which the spinal cord passes.

Atlas

The C1 vertebra, which supports the skull on top of the vertebral column and has no body or spinous process.

Axis

The C2 vertebra, which acts as the axis for rotation of the head and features an upward bony projection called the dens.

Anulus fibrosus

The tough, fibrous outer ring of an intervertebral disc anchored to the margins of adjacent vertebral bodies.

Nucleus pulposus

The gel-like center of an intervertebral disc that resists compression for weight bearing.

Nuchal ligament

The expanded supraspinous ligament in the posterior neck that attaches to the cervical spines and the base of the skull.

Thoracic cage

The structure consisting of 12 pairs of ribs with their costal cartilages and the sternum that protects the heart and lungs.

Sternal angle

The junction between the manubrium and body of the sternum where the second rib attaches.

True ribs

Ribs 1–7, which attach directly to the sternum via their costal cartilages.

False ribs

Ribs 8–12, whose costal cartilages either attach indirectly to the sternum or do not attach at all.

Floating ribs

The last two pairs of false ribs (11–12) that do not attach to the sternum.

Fontanelle

An area of dense connective tissue found at birth between the brain case bones, commonly called a soft spot.

Craniosynostosis

A condition involving the premature closure of a suture line, leading to abnormal skull growth and deformity.