Anatomy Final Flashcards
Platysma
Origin: Inferior border of the mandible; skin of lower
face.
Insertion: Deltopectoral fascia
Nerve: Facial Nerve (CN VII)
Action: Draws skin of neck superiorly and corners of
mouth inferiorly.
Sternocleidomastoid
Origin: Manubrium; medial third of the clavicle
Insertion: Mastoid process
Nerve: Spinal Accessory Nerve (CN XI)
Action: Unilateral - lateral flexion, contralateral rotation
Bilateral - Inferior flexion, superior extension
Anterior Triangle of the Neck
Anterior cervical region
Anterior border of Sternocleidomastoid
Inferior border of the Mandible
Anterior midline of the neck
Posterior Triangle of the Neck
Lateral cervical region
Posterior border of Sternocleidomastoid
Anterior border of Trapezius
Middle third of Clavicle
Scalene Muscles
3 Scalene muscles: Anterior, Middle, Posterior
Origin: Cervical transverse processes
Insertion: 1st Rib (Anterior & Middle)
2nd Rib (Posterior)
Suprahyoid Muscles
Stylohyoid
Mylohyoid
Digastric
Geniohyoid
Action: Elevate the hyoid
Digastric Muscle
Origin: Posterior belly - Mastoid notch
Anterior belly - Digastric fossa
Insertion: Intermediate tendon
Nerve: Posterior belly - Facial nerve (CN VII)
Anterior belly - Mandibular nerve (CN V3)
Infrahyoid “strap” Muscles
Sternohyoid
Omohyoid
Sternothyroid
Thyrohyoid
Name = Origin + Insertion
Nerve: C1 - C4 anterior rami
Action: Depress/stabilize the hyoid
Transverse Cervical Nerve
C2 - C3
Sensory to skin of anterior triangle
Ansa Cervicalis
C1 - C3
Superficial to Carotid Sheath
Motor to Infrahyoid Muscles
Cervical Sympathetic Chain
Superior Cervical Ganglion: C1 - C4
Middle Cervical Ganglion: C5 - C6
Inferior Cervical Ganglion: C7 - C8
- Stellate Ganglion: C7 - T1
Extradural (epidural) Hematoma
Arterial blood pools between the skull and the periosteal layer of dura
Dural Border Hematoma
Blood (usually venous) forces open a space within sublayers of the dura
Subarachnoid Hemorrhage
Blood (usually arterial) escapes into the subarachnoid space.
Most commonly a ruptured aneurysm
Cranial Nerves
Forebrain
CN I - Olfactory nerve
CN II - Optic nerve
Midbrain
CN III - Oculomotor nerve
CN IV - Trochlear nerve
Hindbrain - Pons
CN V - Trigeminal nerve
CN VI - Abducent nerve
CN VII - Facial nerve
CN VIII - Vestibulocochlear nerve
Hindbrain - Medulla
CN IX - Glossopharyngeal nerve
CN X - Vagus nerve
CN XI - Spinal Accessory nerve
CN XII - Hypoglossal nerve
Cranial Nerve Exits - Ethmoid
Cribriform Plate - CN I
Cranial Nerve Exits - Sphenoid
Optic Canal - CN II
Superior Orbital Fissure - CNIII, CN IV, CN V1, CN VI
Foramen Rotundum - CN V2
Foramen Ovale - CN V3
Cranial Nerve Exits - Temporal
Internal Acoustic Meatus - CN VII, CN VIII
Cranial Nerve Exits - Temporal/Occipital
Jugular Foramen - CN IX, CN X, CN XI
Cranial Nerve Exits - Occipital
Hypoglossal Canal - CN XII
Stern’s Laws
- All muscles with ‘tensor’ in the name are innervated by
CN V3 - All muscles with ‘palat-‘ in the name are innervated by
CN X - All muscles with ‘gloss-‘ in the name are innervated by
CN XII
*Hierarchical rules
Trigeminal Nerve (CN V)
Ophthalmic Nerve (CN V1) - Orbit, central forehead, dorsum of nose
Maxillary Nerve (CN V2) - Lateral forehead, lateral nose, most of nasal cavity, palate, upper teeth
Mandibular Nerve (CN V3) - Jaw, lower teeth, ear, temporal region
Ciliary Ganglion
Parasympathetic ganglion
Innervation of the eye
Pterygopalatine Ganglion
Parasympathetic ganglion
Innervation of nasal and oral mucosa and lacrimal gland
Otic Ganglion
Parasympathetic ganglion
Innervation of parotid gland
Submandibular Ganglion
Parasympathetic ganglion
Innervation of the submandibular and sublingual glands
3 - 9 - 7 - 7
C - O - P - S
Oculomotor (CN III) - synapses in the Ciliary ganglion
Glossopharyngeal (CN IX) - synapses in the Otic ganglion
Facial (CN X) - synapses in the Pterygopalatine ganglion
synapses in the Submandibular ganglion
Lacrimal Gland Parasympathetic and Sympathetic Innervation
Postganglionic parasympathetic innervation:
- From pterygopalatine ganglion
- NEW pathway - Direct branches from ganglion to
gland
- FORMER pathway - Zygomatic branch of maxillary
nerve (CN V2)
- Communicating branch to
lacrimal branch of ophthalmic
nerve (CN V1)
- Lacrimal nerve to gland
Sympathetic innervation: Follows parasympathetic
innervation
Branches of the Ophthalmic nerve (CN V1)
Travels through superior orbital fissure
Frontal nerve:
- Supraorbital nerve
- Supratrochlear nerve
- To scalp and superior eyelid
Lacrimal nerve:
* Skin of the lacrimal region and superior eyelid
Nasociliary nerve:
- Short ciliary nerves
- Long ciliary nerves
- Ethmoidal nerves
- Infratrochlear nerve
- To eyeball, superior nasal cavity, bridge of nose, and dorsum of nose
Orbit sensory innervation
Ophthalmic nerve (CN V1) and it’s branches
Sympathetic innervation of the Eye
Preganglionic Axons - Sympathetic chain
Synapse - Superior cervical ganglion (C1 - C4)
Postganglionic Axons - Follow arteries (internal carotid plexus) and join Ciliary nerves entering the eyeball to dilator pupillae
Parasympathetic innervation of the Eye
Preganglionic Axons - Inferior division of Occulomotor nerve (CN III)
Synapse - Ciliary ganglion
Postganglionic Axons - Hitchhike on short ciliary branches of ophthalmic (CN V1) to ciliary muscle and sphincter pupillae
Pupillary Light Reflex
Increase light in one eye will result in pupillary contraction of both eyes
Sensory: CN II
Motor: CN III
Accommodation Reflex
Focus on close objects (change in lens shape) causes pupillary contraction
Sensory: CN II
Motor: CN III
Corneal Blink Reflex
Contact with the cornea causes blinking
Sensory: CN V1
Motor: CN VII
Levator palpebrae superioris
Origin: Common tendinous ring
Insertion: Superior tarsal plate
Nerve: Superior division of Oculomotor (CN III)
Action: Elevate upper eyelid
Superior Rectus
Nerve: Superior division of Oculomotor (CN III)
Action: Strong elevation
Slight adduction
Intorsion
Lateral Rectus
Nerve: Abducent (CN VI)
Action: No elevation or depression
Strong abduction
No extorsion or intorsion
Inferior Rectus
Nerve: Inferior division of Oculomotor (CN III)
Action: Strong depression
Slight adduction
Extorsion
Medial Rectus
Nerve: Inferior division of Oculomotor (CN III)
Action: No elevation or depression
Strong adduction
No extorsion or intorsion
Superior Oblique
Nerve: Trochlear (CN IV)
Action: Strong depression
Slight abduction
Intorsion
Inferior Oblique
Nerve: Inferior division of Oculomotor (CN III)
Action: Strong elevation
Slight abduction
Extorsion
Temporalis
Origin: Floor of temporal fossa; deep surface of
temporal fascia
Insertion: Coronoid process
Nerve: Mandibular nerve (CN V3)
Action: Elevate mandible
Retract mandible
Temporomandibular Joint (TMJ)
Temporomandibular ligament:
- Thickened part of articular capsule
- Temporal bone to neck of mandible
- Restricts posterior and lateral movement
Sphenomandibular ligament:
- Provides passive support
Articular Disc:
- Divides capsule
Superior Cavity:
- Protrusion/retrusion (gliding/translation)
Inferior Cavity:
- Hinge movement (depression, elevation)
Masseter
Origin: Inferior border of zygomatic arch
Insertion: Lateral surface of ramus and angle of the
mandible
Nerve: Mandibular nerve (CN V3)
Action: Elevate and protrude mandible
Lateral Pterygoid (Superior & Inferior)
Origin: S - Infratemporal surface of the greater wing of
sphenoid
I - Lateral surface of lateral pterygoid plate
Insertion: S - Articular disc and capsule of TMJ
I - Pterygoid fovea and capsule of TMJ
Nerve: Mandibular nerve (CN V3)
Action: Protrude mandible and depress chin
Medial Pterygoid (Superficial & Deep)
Origin: S - Maxillary tuberosity
D - Medial surface of lateral pterygoid plate
Insertion: Medial surface of ramus of mandible
Nerve: Mandibular nerve (CN V3)
Action: Elevate and protrude mandible
Auriculotemporal nerve
Encircles middle meningeal artery
Sensory
Carries parasympathetic postganglionics to parotid gland
Otic Ganglion
Parasympathetic ganglion
Preganglionic: Glossopharyngeal nerve (CN IX) via the tympanic plexus and lesser petrosal nerve
Postganglionic: Parotid gland via auriculotemporal nerve
Inferior alveolar nerve
Enters mandibular foramen
Passes through mandibular canal
Sensory
Mental nerve
Branch of inferior alveolar nerve; exits mental foramen
Sensory
Nerve to Mylohyoid
Branch of the inferior alveolar nerve
Motor to: Mylohyoid & anterior belly of digastric
Lingual nerve
Anterior to inferior alveolar nerve
Sensory
Joined by chorda tympani nerve (from CN VII)
Chorda tympani
Branch of the Facial nerve (CN VII)
Joins the lingual nerve
Preganglionic parasympathetics destined for the submandibular ganglion
Taste for anterior 2/3 of tongue
Occipitofrontalis
Frontalis: Elevates the eyebrows and produces
transverse wrinkles on the forehead
Occipitalis: Aids frontalis (by retracting scalp and
aponeurosis)
Nerve: Facial nerve (CN VII)
Orbicularis Oculi
Palpebral portion: Gently closes eye
Orbital portion: Tightly closes eye
Nerve: Facial nerve (CN VII)
Zygomaticus major
Draws the angle of the mouth superolaterally; smiles
Nerve: Facial nerve (CN VII)
Buccinator
Increases rigidity of the cheek
Helps keep food between molars
Resists distention
Nerve: Facial nerve (CN VII)
Orbicularis Oris
Resting activity (tonus) keeps mouth softly closed Constricts and protrudes lips
Nerve: Facial nerve (CN VII)
Satchmo’s Syndrome
Tearing of the orbicularis oris muscle common to brass players
Bell’s Paulsy
Facial nerve damage and paralysis of the muscles supplied by its motor branches.
Eversion of the lower eyelid (corneal problems)
Drooping of the angle of the mouth
- Inability to maintain saliva or food within the oral cavity
Structures within the Parotid Gland
Parotid plexus of the facial nerve (CN VII)
*Motor branches
Retromandibular vein
External carotid artery
Parasympathetic innervation to Parotid Gland
Preganglionic: Glossopharyngeal nerve (CN IX)
- Tympanic plexus
- Lesser petrosal
Synapse in Otic Ganglion
Postganglionics hitchhike on auriculotemporal nerve (CN V3) to parotid gland.
Scalp Wounds
Extensive blood supply = profuse bleeding
Deep wounds (through aponeurosis) gape due to tension in frontalis and occipitalis
Palatoglossus
Origin: Soft palate
Insertion: Lateral side of posterior tongue
Nerve: Vagus nerve (CN X)
Action: Elevate the tongue
Palatopharyngeus
Origin: Soft palate
Insertion: Lateral wall of pharynx
Nerve: Vagus nerve (CN X)
Action: Elevate the pharynx
Intrinsic muscles of the Tongue
Fine control of the tongue
Nerve: Hypoglossal (CN XII)
Extrinsic muscles of the Tongue
Genioglossus (Hypoglossal CN XII)
Hyoglossus (Hypoglossal CN XII)
Palatoglossus (Vagus CN X)
Styloglossus (Hypoglossal CN XII)
Insertion: Posterior-lateral part of the tongue
Tongue Sensory
Anterior 2/3:
- Lingual (from CN V3): general sensory
- Chord tympani (from CN VII hitchhiking on lingual):
special sensory (taste)
Posterior 1/3:
- Glossopharyngeal (CN IX): general sensory and special
sensory (taste)
- Vagus (CN X): Very small contribution to both general sensory and special sensory taste.
Parasympathetic innervation of Submandibular & Sublingual Glands
Preganglionic:
- Facial nerve (CN VII)
- Chorda tympani
- Lingual nerve
- Submandibular ganglion (synapse)
Postganglionic:
- Direct to submandibular gland
- Hitchhike on lingual nerve to sublingual gland
Sympathetic innervation of Submandibular & Sublingual Glands
Via the external carotid plexus
Lingual and facial artery plexuses
Pharyngeal Constrictors
Origin: S - pterygomandibular raphe
M - greater horn of the hyoid
I - thyroid and cricoid cartilage
Insertion: Midline pharyngeal raphe
Nerve: Vagus (CN X)
Killian’s Triangle
Weak point of pharynx in inferior constrictor
Common site of esophageal diverticulum formation
Gag Reflex
Sensory limb: Glossopharyngeal (CN IX)
Motor limb: Vagus (CN X)
Nerves of the Pterygopalatine Fossa
Maxillary Nerve (CN V2): Enter via foramen rotundum
- Zygomatic: exit via inferior orbital fissure
- Infraorbital: exit via inferior orbital fissure
- Pterygopalatine nerves: pass through the
pterygopalatine ganglion
CN V2 branches that pass through pterygopalatine ganglion:
- Greater and lesser palatine nerves: exit via the palatine
canal
- Nasopalatine nerve: Exit via the sphenopalatine foramen
- Posterior lateral nasal nerves: Exit via the sphenopalatine
foramen
Nerve of the pterygoid canal: enters via pterygoid canal
- Facial nerve (CN VII) to greater petrosal nerve (preganglionic parasympathetics)
- Internal carotid plexus to deep petrosal nerve (postganglionic sympathetics)
- Combine to form nerve of the pterygoid canal where it runs into the pterygopalatine ganglion (ONLY parasympathetics synapse)
Kiesselbach’s Area
Highly vascularized area of anastomosis
Site of many profuse nasal bleeding
Special Sensory - Smell
Olfactory Filaments (fila olfactoria): through cribriform plate to nasal epithelium at the roof of the nasal cavity.
Olfactory bulb
Olfactory tract
Submandibular Duct route
Emerges from portion of the submandibular gland superior to mylohyoid
Crosses lingual nerve superiorly
Empties via the sublingual caruncle
Sublingual Gland
Deep to the mucosa of the oral cavity
Empties via numerous ducts in sublingual fold (plica)
Salivary Glands Parasympathetics
Pregnaglionic
- Facial Nerve (CN XII)
- Chorda tympani
- Lingual
Submandibular ganglion (synapse)
Postganglionic
- Direct to SUBMANDIBULAR GLAND
- Hitchhike on lingual nerve to SUBLINGUAL GLAND
Salivary Glands Sympathetics
Innervation via the external carotid plexus
- Lingual artery plexus: sublingual gland
- Facial artery plexus: submandibular gland
Pharyngeal Elevators
Palatopharyngeus - Vagus nerve (CN X)
Stylopharyngeus - Glossopharyneal nerve (CN IX)
Salpingopharyngeus - Vagus nerve (CN X)
