Axial Skeleton Identification

Frontal bone

• Forms forehead and superior part of the orbit

Parietal bone

• Forms sides of cranium, posterior and lateral to frontal bone

Temporal bone

• Inferior to parietal bone

Zygomatic process

• Process that joins with zygomatic bone anteriorly

External acoustic meatus

• Canal leading to eardrum

Styloid process

• Needlelike projection serving as point of attachment for muscles and ligaments in neck

Mastoid process

• Rough projection inferior and posterior to external auditory meatus

Occipital bone

• Most posterior bone of the cranium

Foramen magnum

• Large opening in base of occipital allowing for spinal cord to connect with brain

Occpital condyles

• Rounded projections lateral to forament magnum articulating with atlas

Sphenoid bone

• Bat-shaped bone forming plateau across wdidth of skull

Sella turcica

• Saddle-shaped region in sphenoid midline

• Encloses pituitary gland

Foramen ovale

• Opening posterior to sella turcica

Optic canal

• Allows the optic nerve to pass

Ethmoid bone

• Irregularly shaped bone anterior to sphenoid

• Forms roof of nasal cavity

Crista galli

• Vertical projection to which dura mater attaches

Cribriform plates

• Bony plates lateral to crista galli

Mandible

• Lower jawbone

Maxillae

• Forms upper jawbone and parts of orbit

Palatine bone

• Paired bone posterior to palatine process

Zygomatic bone

• Cheekbone

Lacrimal bone

• Bones forming part of medial orbit

Nasal bone

• Rectangular bone forming bridge of nose

Nasal septum

• Bone that separates your nostrils

Vomer bone

• Blade-shaped bone in median plane of nasal cavity

Sagittal suture

• Where left and right parietal bones meet superiorly

Coronal suture

• Where parietal bones articulate with frontal bone 

Squamous suture

• Where each parietal bone meets with each temporal bone

Lambdoid suture

• Where parietal bones meet with occipital bone posteriorly

Hyoid bone

• Free-floating bone in the throat, point of attachment for tongue and neck muscles

Mental foramen

• Small openings in mandible where nerves and blood vessels exit

Intervertebral discs

• Pads of fibrocartilage that absorb shock and provide spin flexibility

Scoliosis

• Sideways curvature of spine

Kyphosis

• Excessive, forward curvature of spien

• Results in hunched back

Lordosis

• Excessive inward curvature of spine

• Creates swayback, raised buttocks

Body (vertebrae)

• Rounded, central portion

• Faces anteriorly in vertebral column

Vertebral arch

• Composed of pedicles, laminae, and spinous process

• Junction of all posterior extensions

Vertebral foramen

• Opening enclosed by body and vertebral arch

• Where spinal cord passes through

Transverse process (vertebrae)

• Two lateral projections from vertebral arch

Spinous process (vertebrae)

• Single posterior projection from vertebral arch

Articular processes

• Paired projections lateral to vertebral forament

• Allow each vertebrae to articulate with one another

Cervical vertebrae

• First 7 vertebrae, forming neck portion

• Typical cervical vertebrae are smallest, lighest vertebrae

Atlas (C1)

• First cervical vertebrae, lacks body

• Allows you to nod “yes”

Axis (C2)

• Acts as pivot for rotation of atlas and skull

• Has dens (large vertical process) to asct as pivot point; allows you to nod “no”

Thoracic vertebrae

• Next 12 vertebrae forming thoracic cage; only vertebrae that articulate with ribs

• Heart-shaped body, with two small articulating surfaces

Lumbar vertebrae

• Last 5 vertebrae, forming lower back

• Massive blocklike bodies with short, thick spinous process

• Sturdiest and bear most of weight 

Sacrum

• Formed from fusion of 5 vertebrae

• Superiorly articulates with L5 and connects with coccyx inferiorly

Coccyx

• Fused of 3 - 5 irregularly shaped vertebrae

• Remnant of human tailbone

Bony thorax (thoracic cage)

• Composed of sternum, ribs, thoracic cage

• Protects organs of thoracic cavity

Sternum

• Flat bone, fusion of three bones (from top → bottom): manubrium, body, xiphoid process

• Attached to first seven pair of ribs

True ribs

• Ribs that attach directly to sternum by their own costal cartilage

False ribs

• Ribs that have indirect cartilage attachment to sternum

Floating ribs

• Last 2 pairs of ribs that have no sternal attachment