Chapter 6: The Skeletal System - Axial Division

Vocabulary practice flashcards covering the axial division of the human skeletal system based on Chapter 6 lecture notes.

Axial skeleton

The skeletal division consisting of 80 bones that acts as a framework supporting and protecting organs in the body cavities, accommodating special sense organs, and providing muscle attachment sites.

Cranial cavity

A fluid-filled chamber formed by 8 cranial bones (occipital, 2 parietal, frontal, 2 temporal, sphenoid, and ethmoid) that supports and protects the brain.

Facial bones

The 14 bones of the skull, including 6 paired bones (maxillae, palatine, nasal, zygomatic, lacrimal, inferior nasal conchae) and 2 single bones (vomer, mandible).

Paranasal sinuses

Interconnected hollow spaces inside the frontal, ethmoid, sphenoid, and maxillary bones that lessen skull weight, generate mucus, and provide voice resonance.

Hyoid bone

An associated bone of the skull located superior to the larynx that serves as an attachment site for muscles controlling the tongue and larynx.

Fontanels

Fibrous membrane regions between cranial bones in infant skulls, including the anterior, posterior, sphenoidal, and mastoid fontanels.

Primary curves

Spinal curves of the thoracic and sacral regions that sweep posteriorly and develop prior to birth to accommodate abdominopelvic organs.

Secondary curves

Anteriorly sweeping spinal curves in the cervical and lumbar regions that develop in infants and toddlers as they learn to support their head and walk.

Abnormal curves of the vertebral column

Structural distortions of the spine, including kyphosis (exaggerated thoracic curve), lordosis (exaggerated lumbar curve), and scoliosis (abnormal lateral curve).

Atlas (C1)

The first cervical vertebra, which lacks a body, features anterior and posterior arches, and articulates with the occipital condyles to permit head-nodding.

Axis (C2)

The second cervical vertebra, distinguished by the presence of the dens process that acts as a pivot point for head rotation.

Dens

A prominent peg-like projection on the axis (C2) created by the developmental fusion of the atlas body with the axis.

Vertebra prominens (C7)

The seventh cervical vertebra, characterized by a long, slender spinous process and large transverse processes that connect to the ligamentum nuchae.

Ligamentum nuchae

A sturdy elastic ligament running from the spinous process of C7 upward to the external occipital crest.

Transverse foramina

Passageways in cervical vertebrae bounded by the costal process and transverse process, transmitting vital blood vessels.

Bifid tip

A notched or split extremity found on the short spinous processes of typical cervical vertebrae.

Thoracic vertebrae

The 12 vertebrae of the upper back that feature heart-shaped bodies, long posterocaudally angled spinous processes, and costal facets for rib articulations.

Lumbar vertebrae

The 5 lower back vertebrae that possess large oval bodies, triangular vertebral foramina, and flat, stumpy spinous processes.

Thoracic cage

The bony structure of the chest composed of 25 bones (1 sternum and 24 ribs) that shields internal organs and provides attachment for respiratory muscles.

True ribs

Rib pairs 1 through 7 that attach directly to the sternum via individual costal cartilages.

False ribs

Rib pairs 8 through 12 that do not attach directly to the sternum.

Vertebrochondral ribs

Rib pairs 8 through 10 whose costal cartilages merge together before connecting to the cartilage of rib pair 7.

Floating ribs

Rib pairs 11 and 12 that lack any anterior attachment to the sternum or adjacent costal cartilages.