HEAD AND FACE

8 Cranial Bones

The group of skull bones protecting the brain, consisting of Parietal (2), Frontal (1), Occipital (1), Temporal (2), Ethmoid (1), and Sphenoid (1).

14 Facial Bones

The bones forming the structure of the face, consisting of Maxilla (2), Mandible (1), Zygomatic (2), Nasal (2), Inferior nasal conchae (2), Lacrimal (2), Vomer (1), and Palatine (2).

Hyoid Bone

A neck bone positioned inferiorly to the mandible that does not articulate directly with any other bone.

Auditory Ossicles

Paired middle ear bones consisting of the malleus (hammer), incus (anvil), and stapes (stirrup).

Frontal Bone

Cranial bone forming the forehead and part of the cranium; key bony markings include the glabella, supraorbital margin, and supraorbital foramen.

Parietal Bones

Paired cranial bones forming the superior lateral sides of the skull that articulate with the frontal, temporal, and occipital bones.

Paired cranial bones forming the superior lateral sides of the skull that articulate with the frontal, temporal, and occipital bones.

Cranial bone forming the posterior skull and base of the cranial cavity; key bony markings include the external occipital protuberance, superior nuchal line, foramen magnum, and occipital condyles.

Temporal Bones

Cranial bones featuring the squamous portion, zygomatic process, articular tubercle, mandibular fossa, external acoustic meatus, styloid process, and mastoid process.

Sphenoid Bone

Cranial bone forming much of the base of the central skull and part of the temples.

Ethmoid Bone

Cranial bone forming part of the orbit and nasal cavity; features the perpendicular plate, superior & middle nasal conchae, crista galli, cribriform plate, and olfactory foramina.

Mandible

The lower jawbone, which is the only moveable bone of the skull.

Maxillary Bone (Maxilla)

Bone forming the upper jaw, most of the roof of the mouth (hard palate), part of the orbit, and the lateral base of the nose; features alveolar processes and the infraorbital foramen.

Zygomatic Bones

Known as the cheekbones, these form much of the lateral part of the orbit; their temporal process unites with the zygomatic process of the temporal bone to form the zygomatic arch.

Lacrimal Bones

Bones forming part of the orbit that contain lacrimal glands for tear secretion.

Palatine Bones

Bones forming the posterior portion of the hard palate, medial part of the orbit, and contributing to the vertical section of the nasal cavity.

Vomer

Facial bone forming part of the nasal septum.

Nasal Bones

Bones forming the bony base (bridge) and lateral walls of the nose.

Inferior Nasal Conchae

Paired facial bones that project into the nasal cavity.

Temporomandibular Joint (TMJ)

A modified hinge joint between the temporal bone and mandible possessing 3 degrees of freedom (mouth opening/closing, protrusion/retraction, side to side).

Buccinator

Facial expression muscle that holds air in cheeks; originates from the maxilla, mandible, and pterygomandibular raphe.

Zygomaticus Major

Facial expression muscle known as the smile muscle.

Orbicularis Oris

Facial expression muscle known as the kissing muscle.

Levator Labii Superioris Alaeque Nasi

Facial muscle that elevates the upper lip and the ala of the nose, also known as the 'Elvis Muscle' or 'Tear Muscle'.

Corrugator Supercilii

Facial muscle involved in frowning ('SUPER suko').

Risorius

Facial muscle that creates dimples or a fake smile.

Muscles of Mastication ('TIME')

Four chewing muscles innervated by the Trigeminal nerve: Temporalis, Internal (medial) pterygoid, Masseter (all three close the mouth), and External (lateral) pterygoid (opens the mouth)

CN I (Olfactory Nerve)

Purely sensory (SE) nerve originating from the cerebrum (olfactory cortex) for smell; classified as the shortest cranial nerve.

CN II (Optic Nerve)

Purely sensory (SE) nerve originating from the cerebrum (optic cortex) for sight; features the thickest myelin.

CN III (Oculomotor Nerve)

Motor (MO) nerve originating in the midbrain that opens eyes and moves pupil & eyeball via SR, IR, MR, and IO muscles.

CN IV (Trochlear Nerve)

Motor (MO) nerve originating in the midbrain supplying the superior oblique muscle; it is the thinnest, only crossed, and longest intracranial CN.

CN V (Trigeminal Nerve)

Mixed (MI) nerve originating in the pons providing face sensation and chewing motor function; largest CN with Ophthalmic, Maxillary, and Mandibular branches.

CN VI (Abducens Nerve)

Motor (MO) nerve originating in the pons that innervates the lateral rectus muscle to abduct the eye.

CN VII (Facial Nerve)

Mixed (MI) nerve originating in the pons for anterior 2/3 tongue taste, facial expressions, tears, salivation, eye closure, and stapedius muscle.

CN VIII (Vestibulocochlear Nerve)

Purely sensory (SE) nerve originating in the pons responsible for hearing and balance.

CN IX (Glossopharyngeal Nerve)

Mixed (MI) nerve originating in the medulla oblongata for posterior 1/3 tongue taste, uvula sensation, swallowing, and throat muscle movement.

CN X (Vagus Nerve)

Mixed (MI) nerve originating in the medulla oblongata for throat sensation, BP sensing, autonomic function, and phonation; longest overall CN.

CN XI (Accessory Nerve)

Motor (MO) nerve originating in the medulla oblongata supplying Trapezius (shoulder shrug) and SCM (head rotation).

CN XII (Hypoglossal Nerve)

Motor (MO) nerve originating in the medulla oblongata supplying tongue muscles including palatoglossus, genioglossus, hyoglossus, and styloglossus.

Genioglossus

Tongue muscle innervated by CN XII responsible for protruding the tongue.

Palatoglossus

Tongue muscle innervated by CN XII responsible for elevating the tongue.

Hyoglossus

Tongue muscle innervated by CN XII responsible for depressing the hyoid bone.

Styloglossus

Tongue muscle innervated by CN XII responsible for curling the tongue.

LR6 SO4 ATR3

Mnemonic for extraocular muscle innervation: Lateral Rectus innervated by CN VI, Superior Oblique by CN IV, and All The Rest by CN III.

Facial Artery

Main arterial trunk arising from the external carotid artery supplying the lower face and branching into the labial arteries.

Superficial Temporal Artery

Artery arising from the external carotid supplying the temple and lateral scalp region.