Human Skeletal System: Bone Landmarks, Skull Anatomy, and Key Features

Cranial Bones

8 bones that surround and protect the brain. Frontal,Occipital,sphenoid, Ethmoid, parietal(2), Temporal(2)

Facial Bones

14 bones that form the structure of the face. Mandibular, Vomer, Maxillae(2), Zygomatic (2), Lacrimal(2), Nasal(2), Inferior Nasal Conchae(2), Palatine (2)

Frontal Bone Cranial

Forms forehead, upper orbits, supraorbital ridge.

Occipital Bone Cranial

Forms base and back of skull; houses foramen magnum.

Sphenoid Bone Cranial

Butterfly-shaped central cranial bone; houses pituitary gland.

Ethmoid Bone Cranial

Walnut-like bone forming part of orbit, septum, and nasal roof.

Mandible (facial)

Lower jaw; only movable skull bone.

vomer (facial)

Forms posterior portion of nasal septum.

Maxillae (facial)

Upper jaw bones; support upper teeth and form hard palate.

Zygomatic bones (facial)

Cheekbones; form lateral wall/floor of orbits.

lacrimal bones (facial)

Smallest facial bones; located at inner orbit wall.

nasal bones (facial)

Form the bridge of the nose.

inferior nasal conchae (facial)

Separate bones along lateral walls of nasal cavity.

palatine bones (facial)

L-shaped bones forming posterior hard palate.

Sphenoid Bone Key landmarks Sella Turcica

Saddle-like depression of the pituitary gland

Sphenoid Bone Key landmarks Pterygoid processes

Medial and Lateral: attachment for mastication

Hamulus: attachment for sof palate muscles

Sphenoid Bone Key landmarks Major wing

Forms part of orbit and skull

R-Foramen Rotundum

O-Foramen Ovale

S- Formamen Sphinosum

S- Superior Orbital Fissue

Ethmoid Bone Key Landmark

Crista Galli: Vertical projection serving as an attachment point for the meninges of the brain.

Cribriform Plate of ethmoid bone

Perforated horizontal plate forming the roof of the nasal cavity; serves as a passageway for the olfactory nerve fibers.

perpendicular plate of ethmoid bone

Thin vertical plate forming the superior portion of the nasal septum (articulates with the vomer).

Superior & Middle Nasal Conchae (Turbinates)

Scroll-like bony projections extending into the nasal cavity that regulate and direct airflow.

Temporal Bone

Paired cranial bones forming the lateral walls of the skull, divided into three anatomical portions.

Squamous Portion temporal bone

Contains the zygomatic process (forms part of the zygomatic arch/cheekbone).

tympanic portion of temporal bone

Forms the majority of the external acoustic meatus (ear canal).

Petrous Portion

Contains the mastoid process (attachment point for the Sternocleidomastoid SCM muscle) and mastoid notch.

Styloid Process, jugular notch

foramen magnum of occipital bone

Large opening formed entirely by the occipital bone for spinal cord passage.

Occipital Condyles occipital bone

Rounded articulations located on either side of the foramen magnum that form a movable joint with C1 (Atlas).

Hypoglossal Canals occipital bone

Paired canals transmitting Cranial Nerve XII (Hypoglossal nerve).

Maxilla

Paired Upper Jaw.

Body of Maxilla

Contains the maxillary sinus, infraorbital foramen (local anesthesia landmark), and canine fossa.

palatine process of maxilla

Forms the anterior portion of the hard palate; contains the median palatine suture and incisive foramen (LA landmark).

Mandibular Condyle

Articulates at the articular fossa of temporal bone (forms TMJ).

Fossae of the mandible

Internal depressions housing salivary glands (sublingual fossa and submandibular fossa).

Hyoid Bone

U-shaped, floating bone located in the neck; does not articulate directly with any other bone.

Atlas (C1)

First cervical vertebra; directly supports the skull by articulating with the occipital condyles.

Axis (C2)

Second cervical vertebra; features a vertical projection called the dens (odontoid process) around which C1 rotates.

paranasal sinuses

4 paired air filled, Frontal sinuses, Ethmoiddal sinuses, sphenodial sinuses, maxillary sinuses