Anatomy axial skeleton

Bones of Axial Skeleton

Practical Terms

I. Skull

A. Cranial Sutures

Joints made of strong, fibrous tissue hold the bones of your skull together.

Coronal Suture Lambdoidal Suture

Sagittal Suture Squamosal Suture

B. Cranium

the part of the skull that encloses the brain

1. Frontal Bone

forms the anterior and superior portions of the skull.

a. Supraorbital foramen

a path for vessels and nerves from the orbit to the superficial region of

the forehead.

2. Parietal Bone (x2)

form the sides and roof of the cranium

3. Occipital Bone

major part of the posterior wall and base of the skull

a. Foramen Magnum

a passage of the central nervous system through the skull connecting the brain with the spinal cord.

b. Occipital Condyles

articulate with the superior articular facets of the atlas (C1 vertebrae) and form a hinge joint allowing flexion and extension of the head.

4. Temporal Bones (x2)

forms lower lateral walls of the skull

a. Mastoid Process

bony projection at the base of the temporal bones on each side of

the skull that serves as an attachment point for several head and neck

muscles.

b. External Auditory Meatus

channels sound to the inner ear

c. Mandibular fossa

oval depression that receives condyle of the mandible

d. Carotid foramen

allows carotid artery carrying oxygenated blood to pass into the

cranium and supply the brain

e. Jugular foramen

transmits jugular vein carrying deoxygenated blood from the brain

to the heart and cranial nerves

f. Articular tubercle

forms anterior boundary of mandibular fossa

g. Styloid process

serves as an anchor point for several muscles associated with the

tongue and larynx; facilitates the movement of the tongue, pharynx,

larynx, hyoid bone, and mandible.

5. Sphenoid Bone

forms the base of the cranium, behind the eye and below the front part of

the brain

a. Sella turcica

holds and protects the pituitary gland

b. Pterygoid process

allows the jaw to move in a horizontal direction during chewing

c. Optic foramen

contains the optic nerve which transmits electrical impulses from

your eyes to your brain

d. Foramen lacerum

allows for passage of facial and sensory nerves

e. Foramen ovale

transmits the mandibular nerve

f. Foramen spinosum

contains arteries, veins, and nerves serving the brain

6. Ethmoid Bone

a small, cube

a. Crista galli

a vertical, wedge

surface of the ethmoid bone; separates the olfactory bulbs.

b. Cribriform plate

a thin, horizontal bone plate that forms the roof of the nasal

cavity and separates the bran from the nasal cavity.

c. Perpendicular plate

projects from inferior surface of ethmoid bone; forms

superior half of the nasal septum

C. Facial Bones

bones that make up the face and are located between the cranium and the mandible

1. Maxilla

bones that form the upper jaw, the roof of the mouth, and parts of the eye socket and nose:

a. Superior Alveolar process

the thick, curved ridge of bone that forms the socket for

the upper teeth

b. Infraorbital foramen

small holes in the maxilla, located below the eye socket and to

the left and right of the nose.

c. Frontal process

thin, long, superior projection found along the side of the nose

forming part of its lateral boundary

d. Anterior nasal spine

projects anteriorly in the midline, inferior to nasal cavity

2. Lacrimal bones

two small bones of the maxilla are roughly the size of the little fingernail and

situated at the anterior portion of the medial wall of each orbit.

a. Lacrimal fossa

opening in the lacrimal bone that provides drainage for the lacrimal

gland (produce tears)

3. Nasal bones

a pair of bony plates that form the left and right bridge of the nose

4. Vomer

forms inferior half of the nasal septum

5. Zygomatic Bones

a pair of bones that form the cheek and part of the eye socket on each

side of the skull

a. Zygomatic arch

bridge of bone extending from the temporal bone at the side of the

head around to the maxilla (upper jawbone) in front

6. Palatine bones

form the rear of the hard palate and part of the wall and floor of the nasal

cavity.

7. Mandible

lower jaw bone

a. Inferior Alveolar process

the thick, curved ridge of bone that forms the socket for

the lower teeth

b. Mental foramen

an opening in the mandible that allows the mental nerve to exit and

enervate the lower lip, cheeks, chin,

c. Mental protuberance

bony protrusion in the front of the lower jaw that forms the chin

d. Condylar process

the process on the mandible that ends in a condyle that

articulates with the temporal bone at the mandibular fossa (TMJ)

e. Mandibular notch

a U

process anteriorly and the condylar process posteriorly.

f. Incisive foramen/incisive canals

an opening in the hard palate that allows nerves

and blood vessels to pass between the nasal and oral cavities

g. Coronoid process

a triangular projection on the mandible that provides an

attachment point for the muscles used for chewing