Chapter 7: Axial Skeleton Practice Flashcards

A set of vocabulary flashcards covering the axial skeleton, including specific skull bones, vertebral structure, thoracic cage components, and developmental changes associated with aging.

Axial Skeleton

The part of the skeletal system consisting of the skull, vertebral column, and thoracic cage, totaling 80 bones.

Appendicular Skeleton

The part of the skeletal system that includes the shoulder and hip bones as well as the upper and lower extremities.

Cranial Bones

A group of eight bones that surround and enclose the brain, including the ethmoid, frontal, occipital, sphenoid, parietal, and temporal bones.

Facial Bones

A group of 14 bones that form the face and have no brain contact, including the vomer, mandible, maxillae, nasal, lacrimal, zygomatic, palatine, and inferior nasal conchae.

Calvaria

Also known as the skullcap; it is the roof of the cranium made of parietal bones and parts of the frontal and occipital bones.

Sutures

Immovable joints between skull bones that typically begin to disappear in adulthood as bones fuse.

Coronal Suture

The junction between the frontal and parietal bones.

Lambdoid Suture

The junction between the occipital and parietal bones.

Sagittal Suture

The junction between the two parietal bones.

Squamous Suture

The junction between the temporal and parietal bones.

Sella Turcica

A feature of the sphenoid bone that houses the pituitary gland.

Crista Galli

An attachment site on the ethmoid bone for cranial dural septa to help stabilize the brain within the skull.

Foramen Magnum

A large opening in the posteroinferior part of the occipital bone that forms part of the base of the skull.

Mandibular Fossa

An articulation point on the temporal bone that joins with the mandible.

Hyoid Bone

A bone located between the mandible and larynx that does not articulate with any other bone and serves as an attachment site for the tongue and larynx muscles.

Auditory Ossicles

Three tiny bones located in the petrous part of each temporal bone (malleus, incus, and stapes) used for hearing.

Fontanelles

Flexible areas of dense regular connective tissue, often called 'soft spots,' that connect infant cranial bones.

Primary Curvatures

The thoracic and sacral curvatures of the spine that appear during fetal development.

Secondary Curvatures

The cervical and lumbar curvatures of the spine that appear at $3$–$4$ months of age to help shift weight over the legs.

Atlas ($C_1$)

The first cervical vertebra which articulates with the occipital condyles of the skull and supports the head.

Axis ($C_2$)

The second cervical vertebra which contains a process called the dens used as a pivot point for head rotation.

Dens

A process on the axis ($C_2$) that permits rotation of the head.

Sacrum

A triangular bone forming the posterior wall of the pelvic cavity, formed from five fused sacral vertebrae ($S_1$–$S_5$).

Coccyx

Also known as the 'tailbone,' it is formed from four coccygeal vertebrae ($Co_1$–$Co_4$) that begin to fuse during puberty.

True Ribs

Ribs $1$–$7$ that articulate anteriorly with the sternum via costal cartilages.

False Ribs

Ribs $8$–$12$ whose costal cartilages do not attach directly to the sternum.

Floating Ribs

The specific pairs of false ribs ($11$ and $12$) that do not articulate with the sternum at all.

Xiphoid Process

The small, inferior-most part of the adult sternum.

Osteoporosis

A condition where skeletal mass and density are reduced, making bones more porous and brittle, which increases the chance of fracture.