Human Anatomy – Axial Skeleton (Chapter 7)

Vocabulary flashcards covering major terms, bones, landmarks, and clinical conditions of the axial skeleton from Chapter 7 lecture notes.

Axial skeleton

80 bones of the skull, vertebral column, and thoracic cage.

Appendicular skeleton

126 bones of the upper and lower limbs plus their girdles.

Cranial bones

Eight bones that enclose and protect the brain.

Facial bones

Bones that form the face, hold teeth, and anchor facial muscles.

Cranial vault (calvaria)

Dome-like superior part of the cranium.

Anterior cranial fossa

Shallow depression of skull base supporting the frontal lobes.

Middle cranial fossa

Cranial floor region that houses the temporal lobes.

Posterior cranial fossa

Deepest skull depression that supports the cerebellum.

Paranasal sinuses

Air-filled cavities in skull bones surrounding the nasal cavity.

Foramen (plural: foramina)

Natural openings in bone that transmit nerves and vessels.

Parietal bones

Paired cranial bones forming superior and lateral skull walls.

Frontal bone

Bone forming the forehead and roofs of the orbits.

Occipital bone

Posterior cranial bone containing the foramen magnum.

Temporal bones

Paired bones inferior to parietals; house middle and inner ears.

Sphenoid bone

Bat-shaped ‘keystone’ bone spanning the cranial floor.

Ethmoid bone

Medial bone between nasal cavity and orbits; contains cribriform plate.

Coronal suture

Joint between parietal bones and frontal bone.

Sagittal suture

Midline joint between right and left parietal bones.

Lambdoid suture

Joint between parietal bones and occipital bone.

Squamous suture

Lateral joint between parietal and temporal bones.

Supraorbital margin

Superior ridge of the orbit on the frontal bone.

Foramen magnum

Large opening in occipital bone for spinal cord passage.

Occipital condyles

Paired projections that articulate with the atlas (C1).

Hypoglossal foramen

Occipital bone opening for cranial nerve XII.

External occipital protuberance

Midline bump on posterior occipital bone anchoring ligamentum nuchae.

Superior and inferior nuchal lines

Occipital ridges that attach neck and back muscles.

Jugular foramen

Temporal-occipital opening for internal jugular vein and CN IX–XI.

Carotid canal

Temporal bone passageway for the internal carotid artery.

Internal acoustic meatus

Temporal canal transmitting cranial nerves VII and VIII.

Optic canal

Sphenoid opening for cranial nerve II.

Superior orbital fissure

Gap in sphenoid transmitting nerves and vessels to orbit.

Foramen rotundum

Sphenoid opening for branch of cranial nerve V (maxillary).

Foramen ovale

Sphenoid opening for mandibular branch of cranial nerve V.

Foramen spinosum

Sphenoid opening for middle meningeal artery.

Cribriform plate

Ethmoid roof perforated by olfactory foramina for CN I.

Mandible

Lower jaw; only movable bone of the skull.

Condylar process

Mandibular projection that forms the temporomandibular joint.

Coronoid process

Anterior mandible projection for temporalis muscle attachment.

Mental foramen

Opening in mandible for vessels and nerves to chin.

Maxillae

Paired ‘keystone’ facial bones forming upper jaw and hard palate.

Infraorbital foramen

Maxillary opening below orbit for infraorbital nerve and vessels.

Zygomatic bones

Cheekbones forming lateral walls of orbits.

Vomer

Thin bone forming inferior part of nasal septum.

Palatine bones

Paired bones completing posterior hard palate.

Nasal bones

Small paired bones forming bridge of the nose.

Lacrimal bones

Tiny bones in medial orbit walls containing lacrimal sac.

Inferior nasal conchae

Thin curved bones projecting into nasal cavity to increase airflow turbulence.

Orbit

Cone-shaped cavity housing the eye; built from seven bones.

Hyoid bone

U-shaped bone inferior to mandible; no direct articulation; supports tongue.

Vertebral column

26-bone column transmitting trunk weight and protecting spinal cord.

Primary curvatures (kyphosis)

Thoracic and sacral curves present at birth.

Secondary curvatures (lordosis)

Cervical and lumbar curves that develop with head-lifting and walking.

Anterior longitudinal ligament

Wide ligament preventing hyperextension of vertebral column.

Posterior longitudinal ligament

Narrow ligament preventing hyperflexion of spine.

Intervertebral disc

Cushion-like pad between vertebrae containing nucleus pulposus and anulus fibrosus.

Nucleus pulposus

Gelatinous core of intervertebral disc absorbing compressive stress.

Anulus fibrosus

Outer fibrocartilage rings of disc that bind vertebrae and limit expansion.

Herniated (slipped) disc

Protrusion of nucleus pulposus through ruptured anulus fibrosus.

Vertebral foramen

Opening formed by vertebral arch and body; houses spinal cord.

Spinous process

Posterior projection from vertebral arch for muscle attachment.

Transverse process

Lateral vertebral projection providing muscle and ligament attachment.

Intervertebral foramina

Openings between vertebrae for spinal nerve exit.

Atlas (C1)

First cervical vertebra lacking body; supports skull and allows nodding 'yes'.

Axis (C2)

Second cervical vertebra bearing the dens; enables head rotation 'no'.

Dens (odontoid process)

Peg-like projection of axis acting as pivot for atlas.

Transverse foramina

Openings in cervical transverse processes for vertebral arteries.

Costal facets

Articular surfaces on thoracic vertebrae for ribs.

Lumbar vertebrae

L1–L5; large kidney-shaped bodies; allow flexion and extension but resist rotation.

Sacrum

Five fused vertebrae forming posterior pelvis; articulates with L5 and coccyx.

Sacral promontory

Anterior projecting ridge on S1 body.

Coccyx

Tailbone made of four fused vertebrae; minimal function.

Thoracic cage

Bony framework of chest: thoracic vertebrae, ribs, sternum, and costal cartilage.

Sternum

Flat bone of chest composed of manubrium, body, and xiphoid process.

Manubrium

Superior sternum part articulating with clavicles and first two ribs.

Xiphoid process

Inferior sternum tip made of hyaline cartilage until ~age 40.

True ribs (1-7)

Ribs attaching directly to sternum via costal cartilage.

False ribs (8-12)

Ribs that attach indirectly or not at all to sternum.

Floating ribs (11-12)

Posterior ribs without any sternal attachment.

Angle of rib

Point where rib curves sharply forward.

Costal groove

Inferior rib indentation housing intercostal nerves and vessels.

Temporomandibular joint (TMJ)

Jaw joint formed by mandibular condyle and temporal mandibular fossa.

Scoliosis

Abnormal lateral curvature of the vertebral column.

Cleft palate

Congenital failure of right and left palatal bones to fuse.

Lumbar spinal stenosis

Degenerative narrowing of lumbar vertebral canal causing nerve compression.

Ligamentum nuchae

Strong ligament attaching to external occipital protuberance and cervical spines.

Petrous part (temporal)

Hard, pyramid-shaped portion housing middle and inner ear cavities.

Pterygoid process

Inferior sphenoid projections serving as muscle attachment for chewing.

Hard palate

Bony roof of mouth formed by palatine processes of maxilla and horizontal plates of palatine bones.

Auricular surface

Ear-shaped sacral area articulating with the ilium.