CH8 BONES PT4 - AXIAL SKELETON -

A comprehensive set of vocabulary flashcards covering the major bones, joints, and spinal concepts from the human skeleton lecture.

Axial skeleton

The portion of the skeleton that includes the skull, vertebral column (including sacrum and coccyx), rib cage with sternum, and the hyoid bone.

Appendicular skeleton

The bones of the limbs; begins with the clavicle and includes the shoulder girdle, arms, legs, and pelvis (os coxae).

Clavicle

An appendicular bone that forms the sternoclavicular joint with the sternum, linking the upper limb to the axial skeleton.

Sternoclavicular joint

The joint between the sternum (axial skeleton) and the clavicle (appendicular skeleton).

Os coxae

Hip bones; part of the pelvis that joins the sacrum at the sacroiliac joint.

Sacroiliac joint

Joint between the sacrum and the ilium, connecting the axial and appendicular skeleton.

Hyoid bone

A horseshoe-shaped bone in front of the larynx; unique in that it does not form a joint with another bone; muscles/ligaments attach to it; fracture can indicate strangulation.

Cranium

The part of the skull that houses the brain; contains eight cranial bones.

Cranial bones

The eight bones of the cranium: frontal, two parietals, two temporals, occipital, sphenoid, and ethmoid.

Frontal bone

A cranial bone that forms the forehead and contributes to the orbital cavities.

Parietal bone

Paired cranial bones forming the sides and roof of the cranium (two in total).

Temporal bone

Paired cranial bones located near the ears, containing structures of the ear.

Occipital bone

Cranial bone at the back of the skull; articulates with the atlas via the occipital condyles.

Sphenoid bone

A central cranial bone that articulates with all the cranial bones; lies at the base of the skull and helps form the orbit; contains the sella turcica region for the pituitary gland.

Ethmoid bone

Cranial bone between the nose and the orbits; contributes to the nasal cavity and the medial walls of the orbits.

Maxillae

Upper jaw bones; contain alveolar sockets for teeth; form the anterior two-thirds of the hard palate; fuse at the midline.

Palatine bones

Two bones forming the posterior part of the hard palate; contribute to the nasal cavity and the orbit.

Zygomatic bones

Cheek bones; form part of the orbit.

Nasal bones

Two small bones forming the bridge of the nose.

Lacrimal bones

Small bones forming part of the medial wall of each orbit; contain the nasolacrimal canal for tears.

Inferior nasal conchae

Paired bones with a hook shape; form the inferior turbinates in the nasal cavity to help humidify and filter air.

Vomer

A small triangular bone forming part of the nasal septum.

Mandible

Lower jaw bone; the only movable bone of the skull via the temporomandibular joint; contains teeth sockets (alveoli).

Temporomandibular joint (TMJ)

The joint between the mandible and the temporal bone; the only movable joint in the skull; functions like a hinge.

Alveolar sockets

Sockets in the maxillae and mandible that hold teeth.

Hard palate

The bony palate formed by the anterior maxillae (two-thirds) and the posterior palatine bones (one-third); fusion is necessary during development.

Intervertebral disc

Fibrocartilage between vertebral bodies that provides cushioning and houses the nucleus pulposus in the center.

Nucleus pulposus

The gel-like center of an intervertebral disc that provides cushioning within the disc.

Intervertebral foramen

Openings between adjacent vertebrae through which spinal nerves exit the spinal column.

Cervical vertebrae

Seven vertebrae in the neck region.

Thoracic vertebrae

Twelve vertebrae in the mid-back that articulate with the ribs.

Lumbar vertebrae

Five vertebrae in the lower back.

Sacrum

A fused set of five vertebrae forming part of the pelvis and connecting to the ilium at the sacroiliac joint.

Coccyx

Tailbone; typically four fused vertebrae.

Atlas (C1)

First cervical vertebra; no vertebral body; has two flat surfaces (condyles) that articulate with the occipital bone; supports the skull.

Axis (C2)

Second cervical vertebra; contains the dens (odontoid process) that pivots with the atlas to enable rotation.

Occipital condyles

The joints on the occipital bone that articulate with the atlas, forming the atlanto-occipital joint.

Scoliosis

Lateral (sideways) curvature of the spine; severe thoracic scoliosis can impair lung expansion and gait.

Kyphosis

Exaggerated thoracic curvature (hunchback); commonly associated with osteoporosis and vertebral collapse.

Lordosis

Exaggerated lumbar curvature (swayback).

Sacroiliac joint

Joint between the sacrum and ilium that links the axial and appendicular skeleton.

Ribs: true ribs

Ribs 1–7 that connect to the sternum via their own hyaline cartilage.

Ribs: false ribs

Ribs 8–12 whose cartilage connects to the cartilage of the rib above rather than directly to the sternum.

Ribs: floating ribs

Ribs 11–12 that do not attach to the sternum or to cartilage of another rib.

Frontal sinus

A paranasal sinus within the frontal bone that contributes to resonance and reduces skull weight.

Maxillary sinus

A paranasal sinus within the maxilla; one of the common sites of sinus infections.

Ethmoid sinus

Paranasal sinus located within the ethmoid area; contributes to nasal cavity air spaces.

Sphenoid sinus

Paranasal sinus within the sphenoid bone; part of the complex sinus system behind the orbits.

Paranasal sinuses

Air-filled spaces in the frontal, maxillary, ethmoid, and sphenoid bones; lightens the skull, aids resonance, and helps drain mucus.

Orbit bones

The orbital socket is formed by multiple bones: frontal, sphenoid, zygomatic, maxilla, lacrimal, ethmoid, and palatine.