Gross Anatomy Flashcards
Mandible
Largest and strongest none of face
Consists of body, rami, coronoid process (temporalis muscle), and condyle
Mandibular foramen
Located on medial side of ramus under the lingula
IA nerve, artery, and vein
Mental foramen
Located below second premolars
Mental nerve (skin and mucous membrane)
Incisive nerve (pulp chambers of anterior teeth)
Scalp
S: skin (epidermis, dermis) C: connective tissue (superficial fascia) A: aponeurosis L: loose connective tissue P: periosteum
Dura mater
Arachnoid
Subarachnoid space
Cerebrum
What attaches to the lingula?
The sphenomandibular ligament
Epidural space
Potential space between periosteum and dura mater
Contains middle meningeal artery
Epidural hematoma = middle meningeal
Dura mater
Membranous outermost meninge that forms venous sinuses
Endosteal layer on periosteum side
Meningeal layer on brain side
Subdural space
Between dura and arachnoid
Contains bridging veins and venous sinuses
Subdural hematoma= bridging vein
Arachnoid
Weblike lattices between dura and pia
Subarachnoid space
Between arachnoid and pia
Filled with CSF
Contains Circle of Willis
Space entered with lumbar puncture
Vertical dura mater folds
Falx cerebri: separates left and right cerebral hemispheres; contains superiors and inferior sagittal sinuses
Falx cerebelli: separates cerebellum; contains occipital sinus
Horizontal dura mater folds
Tentorium cerebelli: separates cerebrum from cerebellum; contains straight, transverse, and superior petrosal sinuses
Uncus: medial parahippocampal gyrus
Diaphragma sella: roof of sella turcica
Dural sinuses
Superior sagittal Inferior sagittal Straight sinus Cavernous sinus (2) Superior petrosal sinus (2) Inferior petrosal sinus (2) Occipital sinus Transverse sinus (2) Confluence of sinuses Sigmoid
Tributaries of dural sinuses
Emissary veins: drain scalp to dural sinuses
Diploic veins: drain diploe of skull to dural sinuses
Meningeal veins: drain meninges into dural sinuses
What major vessel drains the head and neck?
Internal jugular vein
Cavernous sinuses
Anterior: superior and inferior ophthalmic veins, pterygoid plexus
CNs 3, 6, V1, V2
Posterior: superior and inferior petrosal, intercavernous sinus
CN 6, ICA
What sinus connects the cavernous and sigmoid sinuses?
The superior petrosal sinus
Which nerve is the smallest and most medial in the cavernous sinus and will be the first affected by an infection or laterally expanding pituitary tumor?
CN VI
CV III and IV are also in this area
Pterygoid plexus of veins
Located in infratemporal fossa
Surrounds maxillary artery
Drains maxillary vein posteriorly and deep facial vein anteriorly (connects with anterior facial vein)
Ventricular system of brain
Ependymal cells line and produce CSF
Lateral ventricle near caudate nucleus
Inferior horn near hippocampus
Third ventricle near hypothalamus
Fourth ventricle near pons
Choroid plexus and ventricular system regulate intracranial pressure
CSF circulation
- Lateral ventricles
- Foramen of Monro
- Third ventricle
- Cerebral aqueduct
- Fourth ventricle
- Foramina of Magendie (medial) and Luschka (lateral)
- Bathes cisterns in subarachnoid space
- Arachnoid granulations into superior sagittal sinus to empty CSF into venous circulation
Where is CSF made?
Choroid plexus
Ependymal cells can also make CSF
Blood brain barrier
- Blood CSF barrier: tight junctions in choroid plexus epithelial cells allow selective passage
- Vascular endothelial barrier: tight junctions between endothelial cells
- arachnoid barrier: arachnoid cells form a barrier to present substances from dural vessel from diffusing toward brain
Circle of Willis
Posterior cerebral artery Posterior communicating artery Internal carotid artery Anterior cerebral artery Anterior communicating artery
2 vertebral arteries and 2 carotid arteries
What arteries supply medial aspect of frontal and parietal lobes?
Right and left internal carotid arteries
Branch to anterior cerebral artery and middle cerebral artery
What supplies occipital cortex?
Basilar artery (convergence of left and right vertebral arteries)
Branches to posterior cerebral artery
Does the internal carotid artery have branches in the neck?
No
Vertebral arteries branch off of what?
Subclavian arteries
Middle cerebral artery
Largest branch of the ICA
Causes the most ischemic injury if blocked
Leticulostriate arteries, branches of MCA, are often involved in stroke and are thin walked and can rupture
Tongue Innervation
Motor: CN XII
Damage to CN XII causes tongue to deviate to the side damaged
Sensation: CN V3, IX, X
Taste: CN VII, IX, X
Even though the anterior 2/3, posterior 2/3 of tongue and epiglottis have different Innervation (CN VII, CN IX, and CN X respectively), where do their pathways converge?
Solitary tract to nucleus of solitary tract (gustatory nucleus)
Thalamic nucleus (VPM)
Chorda tympani nerve
Part of CN VII
Solitary tract nucleus, superior salivatory nucleus
Arises from geniculate ganglion, emerges from petrotympanic fissure, crosses tympanic membrane and joins lingual nerve (V3)
Taste to anterior 2/3 of tongue
Preganglionic parasympathetic synapse in submandibular ganglion
Inferior surface of tongue
Lingual frenulum: vertical fold in midline
Plica fimbriata: fold of mucous membrane lateral to frenulum
Wharton’s and Rivian ducts: openings to submandibular and sublingual salivary glands
Types of tastebuds
Filiform: rough, avascular, no tastebuds, rough texture of tongue
Fungiform: mushroom shaped, contain tastebuds
Circumvallate: large circular structures with tastebuds
Foliate: lateral surface of tongue, nonfunctional
Muscles controlling the tongue
Bony attachments: genial tubercles, styloid process, and hyoid bone
Innervation of tongue muscles = CN XII (except palatoglossus)
Blood supply = lingual artery
Genioglossus muscle
O: genial tubercles
I: hyoid (inferior) and tongue (superior)
A: protrudes tongue
N: XII
Hyoglossus muscle
O: hyoid
I: side of tongue medial to styloglossus
A: depress tongue, pulls down side
N: XII
Styloglossus muscle
O: styloid process
I: side of tongue
A: pulls tongue up and back
N: XII
Palatoglossus muscle
O: anterior soft palate
I: side and dorsum of tongue
A: pulls tongue up and back
N: X
Intrinsic tongue muscles
Longitudinal: shorten tongue, make dorsum convex (inferior) or concave (superior)
Transversus: narrow and elongate tongue
Verticalis: flattens and broadens the tongue
Speaking sounds:
“La la”
“Mi mi”
“Kuh kuh”
CN XII moved tongue against roof of mouth
CN VII moves lips
CN X raises palate
Hyoglossus muscle relationships
Medial to = lingual artery
Lateral to = lingual vein, nerve, submandibular duct, hypoglossal nerve
Palate nerve, blood supply
Motor Innervation: pharyngeal plexus
Sensory Innervation: V2 (greater palatine posteriorly, nasopalatine anteriorly)
Blood supply: third part of maxillary artery (branch of ECA)
Palatial salivary glands
Mostly mucous
Located beneath mucous membrane if hard and soft palate
Hard palate components
Maxillary bone (palatine processes)
Palatine bones (horizontal plates)
Covered with keratinized mucosa
Palatial salivary glands beneath mucosa
Soft palate components
Muscles: palatopharyngeus, palatoglossus, levator veli palatini, tensor veli palatini; uvular
Covered by non-keratinized mucosa
Anterior zone of sub mucosa contains fat
Posterior zone contains mucous glands
Palatal aponeurosis: fibrous connective tissue over muscles
Soft palate attachments
To the tongue: palatoglossus arches (anterior pillar)
Palatoglossus draws tongue and soft palate together, narrows isthmus of fauces
To the pharynx: palatopharyngeal arches (posterior pillar)
Palatopharyngeus elevated pharynx, closes nasopharynx and aids in swallowing
Uvula
Suspended from soft palate
Bifid uvula from incomplete fusion of palatine shelves
Unilateral damage to pharyngeal plexus causes uvula to deviate contralaterally (pulled to functional side)
Fauces
Fauces are between anterior and posterior pillars
House the palatine tonsils
Tonsils
Pharyngeal: located on nasopharynx and do not have lymph, sinuses not crypts
Palatine: located in isthmus if fauces and contain crypts and lymphoid follicles, but no sinuses
Lingual: located in dorsum of tongue and contain lymphoid follicles each with a single crypt
Waldeyer’s ring
Ring of lymphoid tissue
Lingual tonsil inferiorly
Palatine tonsils laterally
Nasopharyngeal tonsils superiorly
Which two muscles prevent food from entering the nasopharynx during swallowing?
Tensor and levator veli palatini
Tensor vs levator veli palatini
Tensor: origin on greater wing of sphenoid, insertion on hamulus and palatal aponeurosis, tenses palate and opens auditory tube, innervated by V3
Levator: origin on inferior petrous temporal bone, inserts on palatine aponeurosis, elevates and raises palate, innervated by CN X
What two muscles meet at the pterygomandibular raphe?
Buccinator and superior pharyngeal constructor
Pharyngeal muscles - constrictors
Superior, middle, inferior and cricopharyngeus
Contract in waves to propel food
Sensory Innervation from CN X
Motor from CN XI
Pharyngeal muscles - longitudinal muscles
Palatopharyngeus: raises pharynx and larynx during swallowing (CN XI)
Salpingopharyngeus: elevates nasopharynx and opens auditory tube to equalize pressure (CN XI)
Stylopharyngeus: raises pharynx and larynx during swallowing (CN IX)
Which nerves comprise the pharyngeal plexus?
CN IX, X and XI
Innervated constrictors, palatoglossus, Palatopharyngeus, and cricopharyngeus
What is the only muscle innervated by CN IX?
Stylopharyngeus
Three phases of swallowing
- Oral phase: moisten, masticate (CN V), trough tongue (CN XII), voluntary movement of bolus
- Pharyngeal phase: close nasopharynx via tensor veli palatini (CN V) and levator veli palatini (CN X), elevate pharynx and hyoid via style pharyngeus, salpingopharyngeus and Palatopharyngeus (CN IX and X); close pharynx, retroversion of epiglottis, adduction of vocal cords; bolus passes through and constrictors go though wavelike contraction
- Esophageal phase: esophageal peristalsis (CN X) and relaxation
During swallowing, where can food get caught?
Vallecula or pyriform recess
Nasolacrimal apparatus
Lacrimal gland: produces tears
Lacrimal puncta: collects tears and drains to lacrimal canals
Lacrimal canals join lacrimal sac which drains down nasolacrimal duct
Nasolacrimal duct empties underneath inferior nasal concha into inferior meatus
Lacrimal gland
Paired serous glands involved in tear production
Parasympathetic Innervation via superior salivatory nucleus, greater petrosal nerve (CN VII), and lacrimal nerve (CN VI)
Lymphatic drainage of oral cavity
Parotid gland through parotid nodes then to superior deep cervical nodes
Submandibular and sublingual through submandibular and deep cervical nodes
What major vessel supplies all salivary glands?
External carotid artery
Parotid gland
Serous secretion
Stenson’s (parotid) duct
Pre ganglionic Innervation from lesser petrosal nerve (CN IX) synapse in otic ganglion, post ganglionic innervation with auriculotemporal nerve (V3)
Superficial temporal artery and facial artery supply blood
Submandibular gland
Serous and mucous secretion
Wharton’s (submandibular) duct
Empties at sublingual caruncle
Pre ganglionic via chorda tympani (CN VII), synapses at submandibular ganglion, postganglionic goes to gland
Blood supply from facial artery
Submandibular gland
Mucous secretion
Sublingual (Rivian) ducts
Open directly into oral cavity in sublingual fold
Pre ganglionic via chorda tympani (CN VII), synapses at submandibular ganglion, postganglionic at gland
Blood supply from lingual artery
Minor salivary glands
Labial and buccal: mucous only
Von ebners glands: serous only
Glands of Blandin-Nuhn: mixed serous mucous
Which gland emits the highest volume of salivary fluid per day?
Submandibular gland
Parotid is second
Mastication
Process of biting and chewing food to make it soft to swallow
Muscles of mastication
Masseter
Temporalis
Medial and lateral pterygoid
All innervated by CN V3
Accessory muscles: supra- and infrahyoids
Tongue and buccinator are crucial for controlling bolus (CN XII and VII respectively)
A left subcondylar fracture will deviate the mandible to which side?
The left because only the right lateral pterygoid is functional
Masseter muscle
O: superficial head on zygomatic process of maxilla and zygomatic arch, deep head on inner zygomatic arch
I: superficial head on angle of mandible, deep head on lateral ramus
A: elevation and retrusion
N: V3
Temporalis muscle
O: temporal fossa
I: medial coronoid process
A: retrusion and elevation, ipsilateral excursion
N: V3
Medial Pterygoid muscle
O: medial side of lateral pterygoid plate
I: medial mandible angle
A: elevation, some contralateral excursion and protrusion
N: V3
Lateral pterygoid muscle
O: superior head on greater wing of sphenoid, inferior head on lateral side of lateral pterygoid plate
I: superior head on articular capsule and disc, inferior head on condylar neck
A: protrusion, depression, contralateral excursion
N: V3
Which muscles are involved in jaw opening?
Lateral pterygoids, suprahyoids, infrahyoids
Which muscles are involved in jaw closing?
Temporalis, masseter, medial pterygoids
Which muscles are responsible for jaw protrusion?
Pterygoid muscles
Which muscles are responsible for jaw retrusion?
Temporalis, masseter (deep)
Which muscles are responsible for jaw excursion?
Contralateral pterygoid muscles, ipsilateral masseter and temporalis
TMJ
Bilateral synovial joint
Upper compartment = translation
Lower compartment = rotation
TMJ components
Glenoid/mandibular fossa of temporal bone Articular cartilage Disc Condylar cartilage cap Condyle of mandible
Articular capsule surrounds joint with synovium internally
What type of cartilage covers articular surfaces of the TMJ?
Fibrocartilage
Not hyaline as is seen in most synovial joints
Nerves of TMJ
Auriculotemporal nerve (V3): pain in capsule and parasympathetic Innervation to parotid gland
Nerve to masseter (V3): anterior TMJ
Posterior deep temporal nerve (V3): anterior TMJ
TMJ ligaments
Temporomandibular: oblique portion prevents posterior and inferior displacement, horizontal portion prevents lateral displacement
Sphenomandibular: remnant of Meckel’s cartilage that connects sphenoid with mandible lingula
Stylomandibular: connects styloid to angle of mandible
What is the only direction the TMJ can be dislocated?
Anteriorly
Luxation requires assistance
Subluxation auto-reduces
The disc can be pulled or torn anteromedially by the lateral pterygoid
How to reduce a luxated TMJ
Stand behind patient with thumbs on occlusal surface and fingers below chin
Push inferiorly with thumbs while fingers close mandible
Condylar head will slide back into articular fossa
TMJ noises
Click: with anterior disc displacement
Opening: disc clicks over anteriorly moving condyle
Closing: condyle moves posteriorly past disc
Crepitus: associated with osteoarthritis
Dull thud: self-reducing subluxation of condyle
Six TMJ movements
Protrusion Retrusion Opening Closing Medial excursion Lateral excursion
What is the normal range of motion for TMJ opening, protrusively, and laterally ?
50mm open
10mm protrusively
10mm laterally
Cervical vertebrae
C1-C7
C1 = atlas C2 = axis
Transverse foramina allow passage of vertebral artery to form basilar
Atlanto occipital joint
Between C1 and atlas
Allows head to nod yes (flexion and extension)
Atlanto axial joint
Between C1 and C2
Allows head to shake no (pivot)
Platysma muscle
Innervated by CN VII
Blends with orbicularis oris
Superficial to deep cervical fascia
Investing layer of deep cervical fascia contains what muscles and glands?
Sternocleidomastoid, trapezius
Submandibular and parotid glands
Pre tracheal later of deep cervical fascia contains what?
Thyroid gland
Larynx
Pharynx
Esophagus
Prevertebral layer of deep cervical fascia contains what?
Vertebrae and deep cervical muscles
The prevertebral layer is why the thyroid moves with laryngeal muscles ??? Maybe pretracheal
Contents of the carotid sheath
Common carotid artery
Internal jugular vein
CN X
Also lymph nodes, carotid sinus nerve, sympathetic nerves
Retropharyngeal space
Between pharynx and prevertebral fascia
Concern for infection spread because it connects with mediastinum
Posterior triangle of the neck
Anterior - SCM
Posterior - Trapezius
Inferior - clavicle
Floor - splenius capita, levator scapulae, and scalene muscles
Roof: skin, superficial fascia and platysma, deep investing fascia
Contains cervical plexus, great auricular nerve, lesser occipital nerve, subclavian vein, artery, brachial plexus
Anterior triangle of the neck
Anterior - neck midline Posterior - SCM Inferior - inferior border of mandible Floor - pharynx, larynx, thyroid Roof - skin, superficial fascia and platysma, deep investing fascia
Contains infrahyoids, suprahyoids, common/internal/external carotids, internal/external jugular veins, retro mandibular vein, CN X, XI and XII
Submandibular triangle (part of anterior triangle)
Inferior - Digastric
Superior - inferior mandible
Floor - mylohyoid and hyoglossus
Roof - same
Contains submandibular gland, submandibular lymph nodes, hyoglossal nerve, mylohyoid nerve, lingual and facial arteries and veins
Muscular triangle (part of anterior triangle)
Superior border of omohyoid
SCM
Midline of neck
Contains infrahyoid strap muscles
Carotid triangle (part of anterior triangle)
Superior belly of omohyoid
Posterior belly of digastric
SCM
Contains common carotid, internal jugular vein, CNs X, XI, XII, cervical plexus
Sub mental triangle (part of anterior triangle)
Right and left anterior bellies of digastric
Body of hyoid
Contains mylohyoid muscle
What muscles are innervated by the ansa cervicalis?
Sternohyoid
Sternothyroid
Omohyoid
Thyrohyoid is innervated by C1 via CN XII
Sternocleidomastoid muscle
O: manubrium, clavicle
I: mastoid process
A: flexes neck bilaterally, pulls head to shoulder and turns head to opposite side unilaterally
N: CN XI
Trapezius muscle
O: thoracic and cervical spine, ligamentum nucha, superior nuchal line
I: scapula, lateral clavicle
A: extends head bilaterally, elevates shoulder and pulls chin to opposite side unilaterally
N: CN XI
Hyoid bone
U shaped floating bone
Composed of body, greater and lesser horns
Torticollis (head tilting to the affected side) results from injury to what muscle?
SCM
Ligaments attaching to hyoid
Stylohyoid
Hypoepiglottic
Muscles attaching to hyoid
Mylohyoid (CN V3) Anterior digastric (CN V3) Posterior digastric (CN VII) Stylohyoid (CN VII) Hypoglossus (CN XII) Geniohyoid (C1 via XII) Omohyoid (ansa cervicalis) Sternohyoid (ansa cervicalis) Thyrohyoid (C1 via XII)
Digastric muscle
O: anterior head on intermediate tendon, posterior head on temporal bone
I: anterior head on anterior mandible, posterior head on intermediate tendon
A: raises hyoid
N: anterior head V3, posterior head CN VII
Mylohyoid muscle
O: medial mandible (mylohyoid line)
I: median raphe, body of hyoid
A: raises hyoid, base of tongue, FOM
N: V3
Geniohyoid
O: genial tubercles
I: body of hyoid
A: raises hyoid
N: C1 via CN XII
Stylohyoid muscle
O: stylohyoid process
I: greater horn of hyoid
A: raises hyoid
N: CN VII
Omohyoid muscle
O: superior belly on intermediate tendon, inferior belly on superior scapula
I: superior belly on hyoid, inferior belly On intermediate tendon
A: depresses hyoid and larynx
N: ansa cervicalis
Sternohyoid muscle
O: manubrium of sternum
I: hyoid
A: depress hyoid and larynx
N: ansa cervicalis
Sternothyroid
O: manubrium of sternum
I: thyroid cartilage
A: depress larynx
N: ansa cervicalis
Thyrohyoid
O: thyroid cartilage
I: hyoid
A: depresses hyoid and larynx
N: C1 via CN XII
Cervical plexus
C1-C4
Cutaneous Innervation to skin of neck, shoulder, and anterior upper chest wall
Motor to infrahyoid muscles and geniohyoid
Phrenic nerve (C3, 4, 5) is contributed in part by ansa cervicalis
Supraclavicular nerves innervated skin over shoulder
Transverse cervical nerve carries sensory Innervation to anterior and lateral neck
Ansa cervicalis
Motor division of cervical plexus
Comes from C1 and runs with CN XII
Innervates infrahyoids (except thyrohyoid), geniohyoid
Branches of C2, C3 loop (sensory)
Lesser occipital nerve (C2): skin of neck and scalp
Great auricular nerve (C2, 3): skin over parotid gland, posterior auricle, mandible to mastoid
Transverse cervical nerve (C2, 3): skin of anterior triangle
Phrenic nerve
C3, 4, 5
Contains motor, sensory, and sympathetic nerve fibers
Sole motor Innervation to diaphragm
External carotid artery branches
Ascending pharyngeal artery Lingual artery Facial artery Occipital artery Posterior auricular artery Maxillary artery (terminal branch) Superficial temporal branch (terminal)
What does the ECA supply?
Face Thyroid Salivary gland Tongue Jaws Teeth Carotid sinus (baroreceptors) Carotid body (chemoreceptors)
