Skull Anatomy and Muscles of Facial Expression

Comprehensive practice flashcards covering skull bones, foramina, cranial fossae, cranial nerve pathways, and the muscles of facial expression.

Frontal Region

Anatomical region of the head that corresponds to the forehead.

Temporal Region

Anatomical region of the head located on the lateral skull superior to the ear.

Parietal Region

Anatomical region of the head located superiorly and posterolaterally on the skull.

Occipital Region

Anatomical region of the head located on the posterior skull.

Nuchal Region

Anatomical region of the head situated at the back of the neck.

Auricular Region

Anatomical region of the head corresponding to the external ear.

Infraorbital Region

Anatomical region of the face situated immediately below the eye.

Buccal Region

Anatomical region of the face corresponding to the cheek.

Zygomatic Region

Anatomical region of the face corresponding to the lateral superior cheek.

Parotid Region

Anatomical region of the head located at the lateral posterior cheek.

Mental Region

Anatomical region of the face corresponding to the chin.

Cranial Bones

The 8 bones that enclose and protect the brain and provide muscle attachment sites; consists of 4 unpaired bones (ethmoid, frontal, occipital, sphenoid) and 2 paired bones (parietal, temporal).

Facial Bones

The 14 bones that form the framework of the face, form sensory cavities, hold the teeth, and anchor facial muscles; consists of 2 unpaired bones (vomer, mandible) and 6 paired bones (maxillae, nasal, lacrimal, zygomatic, palatine, inferior nasal conchae).

Sutures

Immovable fibrous joints connecting skull bones; the four major sutures are the coronal, lambdoid, sagittal, and squamous sutures.

Fontanelles

Flexible regions of dense regular connective tissue connecting cranial bones in an infant skull, notably including the anterior and posterior fontanelles.

Anterior Cranial Fossa

Cranial floor depression that accommodates the frontal lobes of the brain, the olfactory bulb, and the olfactory tract.

Middle Cranial Fossa

Cranial floor depression that accommodates the temporal lobes of the brain and the pituitary gland.

Posterior Cranial Fossa

Cranial floor depression that accommodates the cerebellum.

Frontal Bone

Single cranial bone that forms the forehead and the roof and superior margin of the orbit; contains the supraorbital foramen for the supraorbital nerve.

Temporal Bone

Paired cranial bone forming the lateral skull; features the zygomatic process, external acoustic meatus, mandibular fossa, mastoid process, styloid process, and carotid canal.

Mandibular Fossa

Depression on the inferior surface of the temporal bone that articulates with the mandibular condyle to form the temporomandibular joint (TMJ).

Mastoid Process

Prominent projection on the temporal bone that serves as an attachment site for the sternocleidomastoid muscle.

Styloid Process of Temporal Bone

Needle-like projection extending downward from the temporal bone that provides attachment for several ligaments and muscles, including the stylohyoid.

Carotid Canal

Passageway within the temporal bone that transmits the internal carotid artery.

Stylomastoid Foramen

Opening on the temporal bone that serves as the passageway for the facial nerve (CN VII).

Occipital Bone

Single cranial bone that forms the posterior skull and the base of the cranium; features the foramen magnum, occipital condyles, hypoglossal canal, and boundaries of the jugular foramen.

Foramen Magnum

Large opening in the occipital bone that transmits the transition of the medulla oblongata to the spinal cord, the vertebral arteries, and the accessory nerve (CN XI).

Occipital Condyles

Paired curved projections on the occipital bone that articulate with the atlas ($C_1$) at the atlanto-occipital joint.

Jugular Foramen

Passageway situated between the temporal and occipital bones that transmits the glossopharyngeal nerve (CN IX), vagus nerve (CN X), accessory nerve (CN XI), and the internal jugular vein.

Hypoglossal Canal

Bony canal in the occipital bone that serves as the passageway for the hypoglossal nerve (CN XII).

Sphenoid Bone

Central bat-shaped cranial bone spanning the width of the cranial floor; contains greater and lesser wings, sella turcica, optic canal, superior orbital fissure, foramen rotundum, and foramen ovale.

Sella Turcica

Saddle-shaped depression in the sphenoid bone whose hypophyseal fossa houses and protects the pituitary gland.

Optic Canal

Foramen in the lesser wing of the sphenoid bone that transmits the optic nerve (CN II) and the ophthalmic artery.

Superior Orbital Fissure

Diagonal cleft in the sphenoid bone between the greater and lesser wings that transmits the oculomotor nerve (CN III), trochlear nerve (CN IV), ophthalmic nerve ($V_1$ of CN V), and abducens nerve (CN VI).

Foramen Rotundum

Circular canal in the sphenoid bone that transmits the maxillary branch of the trigeminal nerve (CN $V_2$).

Foramen Ovale

Oval opening in the sphenoid bone that transmits the mandibular branch of the trigeminal nerve (CN $V_3$).

Ethmoid Bone

Deep midline cranial bone located posterior to the nasal cavity that forms parts of the anterior cranial fossa, nasal septum, nasal cavity, and medial orbital wall.

Crista Galli

Vertical superior projection of the ethmoid bone that serves as the attachment site for the falx cerebri.

Cribriform Plate

Horizontal plate of the ethmoid bone perforated with cribriform foramina that transmit the olfactory nerve (CN I) fibers.

Perpendicular Plate of Ethmoid Bone

Thin vertical bony plate of the ethmoid bone that forms the superior portion of the bony nasal septum.

Vomer

Unpaired midline facial bone that forms the inferior portion of the bony nasal septum.

Maxilla

Paired upper jaw bone forming the anterior hard palate, floor of the orbit, and maxillary sinus; articulates with every facial bone except the mandible and contains alveolar processes for teeth.

Palatine Bone

Paired facial bone situated deeply to form the posterior hard palate, part of the nasal cavity walls, and a small portion of the orbital floor.

Mandible

Unpaired lower jaw bone consisting of a body, ramus, angle, coronoid process (temporalis attachment), mandibular condyle (articulating at the TMJ), mental protuberance, mental foramen, and mandibular foramen.

Superior Wall of Orbit

Roof of the eye orbit formed by the frontal bone and the sphenoid bone.

Inferior Wall of Orbit

Floor of the eye orbit formed by the zygomatic bone, maxilla, and palatine bone.

Medial Wall of Orbit

Medial boundary of the eye orbit formed by the maxilla, lacrimal bone, ethmoid bone, and sphenoid bone.

Lateral Wall of Orbit

Lateral boundary of the eye orbit formed by the zygomatic bone and sphenoid bone.

Inferior Nasal Conchae

Paired curved facial bones that project into the nasal cavity to increase surface area and generate turbulent airflow for air conditioning.

Muscles of Facial Expression

Skeletal muscles that originate on skull bones or superficial fascia and insert into the superficial fascia of the skin; all are innervated by the facial nerve (CN VII), except the levator palpebrae superioris which is innervated by the oculomotor nerve (CN III).

Occipitofrontalis

Muscle of the scalp comprising a frontal belly that elevates eyebrows and wrinkles the forehead, an occipital belly that retracts the scalp, and an intervening epicranial aponeurosis.

Epicranial Aponeurosis

Broad sheet-like tendon spanning the superior cranium that connects the frontal and occipital bellies of the occipitofrontalis muscle.

Procerus

Muscle of the nose that acts to depress the medial eyebrow and wrinkle the skin over the bridge of the nose.

Nasalis

Muscle of the nose that compresses the bridge, depresses the tip of the nose, and elevates the corners of the nostrils.

Corrugator Supercilii

Muscle of the eye that pulls the eyebrows inferiorly and medially, generating vertical wrinkles above the nose.

Orbicularis Oculi

Circular sphincter muscle surrounding the orbit that closes the eyelids (blinking, squinting) and draws the eyebrows inferiorly.

Levator Palpebrae Superioris

Eye muscle innervated by the oculomotor nerve (CN III) that functions to elevate the superior eyelid.

Buccinator

Deep muscle of the cheek that compresses the cheek (whistling, sucking), draws the corner of the mouth laterally, and holds food between the teeth during chewing.

Orbicularis Oris

Sphincter muscle encircling the mouth that closes, purses, and protrudes the lips (kissing, whistling).

Risorius

Facial muscle that draws the corner of the lip laterally and downward, tensing the lips.

Mentalis

Muscle of the chin that elevates and wrinkles the skin of the chin and protrudes the lower lip.

Depressor Anguli Oris

Muscle that draws the corner of the mouth inferiorly and laterally.

Depressor Labii Inferioris

Muscle of the lower face that acts to depress the lower lip.

Levator Anguli Oris

Muscle of facial expression that widens the oral fissure and elevates the corners of the mouth.

Levator Labii Superioris

Muscle that opens the lips, elevates the upper lip, and furrows the upper lip.

Levator Labii Superioris Alaeque Nasi

Muscle that elevates the upper lip and dilates the nostrils.

Zygomaticus Major

Muscle originating from the zygomatic bone that raises the lateral corners of the mouth during smiling.

Zygomaticus Minor

Muscle originating on the zygomatic bone anterior to zygomaticus major that raises the lateral corners of the mouth.

Platysma

Superficial sheet-like neck muscle that tenses the skin of the inferior face and neck, and depresses the jaw.