Gross Anatomy of Head and Neck

Question 1

What are the three gates beween the mouth and the airways?

Answer 1

1) soft palate elevates to close off nose from mouth
2) epiglottis depresses to close off larynx
3) vocal cords in larynx

Question 2

What is the action of the genioglossus?

Answer 2

Extrinsic paired muscles push tongue out of mouth. Run from mandible to hyoid + tongue

Question 3

What is the action of hyoglossus

Question 4

What are the layers of the scalp and skull?

Answer 4

Skin

Connective tissue

Aponeurosis connecting frontalis and occipitalis muscles

Loose CT

Periosteum

_N.B: _SCA are fused and can shear at the loose CT layer

Periosteum (AKA epicranium)

Outer Table

Diploe (medullary cavity)

Endostium (endostial layer of dura)

Inner Table

Question 5

Where do emissary veins run?

Answer 5

From the CT underlying the skin of the scalp, through the skull, into the superior saggital sinus.

Question 6

What are the meningeal coverings of the brain and spinal cord? What spaces are potential? What vessels run where?

Answer 6

Potential Space: epidural containing middle meningeal artery

Dura mater:

• endostial layer (fused to….)
• meningeal layer

Potential Space: subdural containing…

Arachnoid mater

Real space: subarachnoid, inflated by CSF

Pia mater (fused to brain surface

Question 7

What are the three dural reflections and the herniation syndromes associated with them?

Answer 7

Falx cerebri:

• separates the hemispheres
• Subfalcine herniation (AKA: cingulate): compression of ACA gives lower limb plegia/paralysis

Tentorium

• separates the cerebellum from the rest of the brain
• subtentorial (AKA uncal): triad of mydriasis (III), contralateral plegia (cerebral peduncle), coma (RAS in brainstem)

Sellar diaphragm (no herniation syndrome)

Question 8

Answer 8

Straight sinus connects superior and inferior saggital sinuses

Question 9

Answer 9

cavernous sinus receives draininage from orbits

inferior petrosal sinus is sampled in the diagnosis of Cushing’s disease

Sinuses ultimately empty into the internal jugular veins

Question 10

Question 11

Question 12

What structures pass through:

• optic canal
• cribiform plate

Answer 12

These are foramina in the anterior cranial fossa:

• the olfactory “nerve” (CNI) through the cribiform plate
• CN two (three letters, three structures pass through the optic canal), the opthalmic artery and central retinal vein (and sympathetics…)

Question 13

What structures pass through:

• Superior orbital fissure
• Foramen rotundum
• Foramen ovale
• Foramen spinosum
• Foramen lacerum

Answer 13

These foramina are in the middle cranial fossa:

• Superior orbital fissure–> orbit
  
  • III, IV, V1, VI, superior opthalmic veins
• Foramen rotundum–> pterygopalatine fossa
  
  • V2
• Foramen ovale–> infratemporal fossa
  
  • V3 (“3” kind of looks like a”o”, or Some Random hOle)
• Foramen spinosum –> infratemporal fossa
  
  • Middle meningeal artery (think: an MMA fighter snapping someone’s spine)
• Foramen lacerum (not a true foramen in life)

Question 14

What passes through:

• internal auditory meatus
• jugular foramen
• hypoglossal canal
• foramen magnum

Answer 14

These are in the posterior cranial fossa:

• internal auditory canal: VII, VIII
• Jugular foramen: IX, X, XI, jugular veins
• hypoglossal canal: XII
• foramen magnum: spinal cord, spinal arteries

Question 15

Which foramen do the following structures go through:

• each cranial nerve
• opthalmic artery
• superior opthalmic veins
• middle meningeal artery
• jugular veins
• vertebral arteries

Answer 15

I: cribiform plate

II: optic canal (with opthalmic artery, central retinal vein, sympathetics)

III: superior orbital fissure (with IV, V1, VI, opthalmic veins)

IV: SOF

V1: SOF

V2: foramen rotundum

V3: foramen ovale

VI: SOF

VII: internal auditory meatus

VIII: internal auditory meatus

IX: jugular foramen

X: jugular foramen

XI: in through foramen magnus, out through jugular foramen

XII: hypoglossal canal

Question 16

Greater and lesser wings of sphenoid bones, and medial and lateral pteygoid plates

Answer 16

Question 17

What is the blood input and output of the cavernous sinus? What is the clinical significance?

Answer 17

Receives blood from the opthalmic veins and other veins, drains into into the superior and inferior petrosal sinuses –> jugular

Lots of anastomoses, site for retrograde infection from face to enter brain (trauma to “danger area of face”).

The cavernous sinus is the only site in the human body where an artery passes though an entirely venous structure, so it is possible to have an arterio-venous fistula.

The pituitary lies between the two sinuses and an adenoma may compress the nerves

Question 18

Which meningeal layers is the cavernous sinus located between?

Answer 18

The two layers of dura (periosteal and meningeal)

Question 19

What structures pass through the cavernous sinus and where are they located?

Answer 19

Lateral wall: CN III, IV, V1 (all go thru SOF) and V2 (travels to rotundum)

Medial wall (with internal carotid + carotid plexus): VI

Question 20

Which bone is this?

Question 21

The muscle cone of the orbit..

Question 22

Components of the lacrimal apparatus and the flow of tears

Answer 22

Lacrimal gland–> conjunctival sac–> tears wash medially across eye–> collected in superior and inferior lacrimal puntum–>lacrimal canaculi–> lacrimal sac–> nasal cavities

Question 23

What are the areas of transition of the skull?

Answer 23

pterygopalatine fossa

infratemporal fossa

Question 24

What cranial structures would you be concerned about with a penetrating wound to the medial, roof, floor and lateral wall of the orbit?

Answer 24

Medial: nasal cavity, ethmoid air sinuses

Floor: maxillary sinuses

Roof: anterior cranial fossa

Lateral wall: temporal fossa (temporalis muscle) or communicating branch of VII…

Question 25

What demarcates the three cranial fossa?

Answer 25

lesser wing of sphenoid Petrous ridge

Question 26

Where does the trigeminal ganglion sit? What is housed in the ganglion?

Answer 26

All the GSA of V cell bodies (no synapses because it is a sensory ganglia) On the greater wing of the sphenoid )?)

Question 27

What are the modalities in V1? What are the main branches?

Answer 27

All GSA 1) _Frontal nerve_ travels along medial wall of orbit --\>divides into--\> _supratrochlear_ (travels above trochlea) and _supraorbital_ 2) _lacrimal nerve_ travels along lateral wall of orbit, thru lacrimal galn and out onto face 3) Nasocilliary crosses over II and divides into _anterior ethmoid nerve_ (pins nerve to medial wall) and _infratrochlear nerve_. Also gives off ciliary branches (sensory to cornea, afferent limb of corneal reflex). Short ciliary branches contain PNS from CN III and are before the nasociliary crosses over II. Long ciliary branches come off after it crosses over II

Question 28

How does PNS from CNIII get to the eye?

Answer 28

Oculomotor nerve contains preganglionic fibers, exits through supraorbital fissure. Synapse in motor root ganglion (cilliary ganglion on cillary nerve) and hop into ciliary nerve to become "short ciliary nerves" and enter eye that way to get to constrictor pupillae and cilliary muscle (rounds lens)

Question 29

What are the muscles of mastication innervated by V3 and what does each do?

Answer 29

There are 4: * Temporalis: occludes jaw. Originates at upper border of temporal fossa and inserts on the coronoid process of mandible. * Masseter:occludes jaw, pulling on the lateral side of the mandible. Originates on the zygomatic arch and inserts on the ramus of the mandible * Lateral pterygoid: fibers are oriented horizontally, so protrudes the mandible. * Medial pterygoid: occludes jaw, pulling on the medial side of mandible

Question 30

Just a nice diagram

Question 31

What are the divisions of the oculomotor nerve and what does each innervate?

Answer 31

Superior division: * superior rectus, levatro palpebrae superioris Inferior division * medial rectus * inferior rectus * inferior oblique * PNS to cilliary ganglion and short ciliary nerves

Question 32

Extraocular muscles

Question 33

Lateral extraocular muscles

Question 34

What is the temporal fossa? What is the orgin, insertion and innervation of the temporalis muscle?

Answer 34

Major contents in the temporalis muscle, a muscle of mastication innervated by deep temporal nerves of V3, originating on the upper border of the temporal fossa, passing underneath the zygomatic arch and inserting on the coronoid process of the mandible

Question 35

What are the parts of the mandible?

Answer 35

Question 36

Lingual nerve in relation to muscles

Question 37

Where is the infratemporal fossa in relation to the temporal fossa?

Answer 37

Question 39

Where do the lateral pterygoids attach?

Answer 39

Lateral (has 2 heads) * upper: infratemporal crest--\> mandible near TMJ * lower: lateral plate of pterygoid process --\> near TMJ

Question 40

Where do the medial pterygoids attach?

Answer 40

Medial pterygoid has two heads (superficial and deep) * Deep head: the medial surface of the lateral pterygoid plate--\> ramus of mandible * Superficial head: maxilla --\> ramus of mandible (**m**edials pterygoids attach to the ramus of the **m**andible, whereas the lateral pterygoids attach near the TMJ)

Question 41

What are the important features of the TMJ? What happens everytime you open your mouth?

Answer 41

It's actually two joints in one. The lower joint is a hinge, the upper joint allows the mandible to slide forward onto the articular tubercle of the mandible. Everytime you open your mouth the mandible slides forward so it can clear structures in the neck posterior to the mandible.

Question 42

Where does V3 exit the skull and what are the important branches?

Answer 42

Exits through the foramen ovale into the infratemporal fossa * _Auriculotemporal nerve_ (behind parotid, wraps around middle meningeal artery. GSA to temporal region. ) * _Lingual nerve_ (GSA to the anterior 2/3 tongue (glossopharygeal (IX) does posterior 1/3) (Picks up _chorda tympani_ (from VII) which does SSA (taste) to anterior 2/3 tongue and PNS to all glands below the oral fissure. Synapses in the _otic ganglion_ which is just medial to V3) * _Inferior alveolar nerve_ (enters mandible and does sensory to the lower mandible and teeth. Terminates as the _mental nerve_) * _Buccal nerve_ part of anterior division of V3 (not labelled in diagram)

Question 43

Review Card: What are the 3 areas that the trigeminal nerve goes into? What are the major branches?

Answer 43

V1 (opthalmic): the orbit, via the supraorbital fissure * frontal (--\> supratrochlear and supraorbital) * Nasociliary (short ciliary, long ciliary, anterior ethmoid, infratrochlear) * Lacrimal (PNS....) V2 (maxillary): the pterygopalatine fossa V3 (mandibular): the infratemporal fossa * inferior alveolar * lingual (+submandibular ganglion) * auriculotemporal

Question 44

What are the PNS ganglia in the head? Where are they found and what nerves do they travel with?

Answer 44

**Ciliary ganglia** (PNS from CN III) hops on short ciliary branches of nasociliary nerve of V1 and goes into orbit to innervate ciliary muscles (round lens) and constrictor pupillae. **Submandibular ganglia:** (PNS from CN VII via _chorda typani_) comes out of petrotympanic fissure, hops on _lingual nerve_ of V3 in infratemporal fossa then synapses in the submandibular ganglion and does all the *glands below the oral fissure*. Chorda tympani also carries SSA (taste) to ant. 2/3. **Otic ganglia**: PNS from IX, via _lesser petrosal_ branch, exits foramen ovale with V3 (don't need to know how it gets from IX to the foramen ovale) hops on the _auriculotemporal n._, synapses in the otic ganglia, then innervates the *parotid gland* **Pterygopalatine ganglion**: PNS from CN VII (_greater petrosal n._) synapses on the pterygopalatine ganglion and travel to the palatine (via. the _descending palatine n._), nasal (via. _nasopalatine n._) lacrimal (via. communicating branch (all PNS fibers) of _zygomaticofacial n._ to the _lacrimal n._ of V1) and pharyngeal glands (via _pharyngeal n._)

Question 45

What are the boundaries of the infratemporal fossa?

Answer 45

1. medial pterygoid: from medial surface of lateral pterygoid plate, going to the medial mandible 2. Zygomatic arch

Question 46

Branches of the external carotid

Answer 46

Question 47

What is the major artery passing through the infratemporal fossa?

Answer 47

The maxillary artery, a branch of the external carotid, which gives off the middle meningeal that goes through the foramen spinosum. (auriculotemporal nerve wraps around this)

Question 48

What three bones make up the pterygopalatine fossa?

Answer 48

1) Palatine 2) Maxillary 3) Sphenoid (specifically the ?lateral pterygoid plate

Question 49

What are the 6 canals associated with the pterygopalatine fossa?

Answer 49

1) sphenopalatine foramen (--\>nasal cavity, carries _nasopalatine n.)_ 2) foramen rotundum (cranial cavity- _V2_ comes through here) 3) Pterygoid canal (--\> cranial cavity, carries _greater petrosal n._ (PNS from VII) 4) Pharyngeal canal (--\> nasopharynx, carries _pharyngeal nerve_) 5) Palatine canal (--\>roof of oral cavity, carries _descending palatine_ branch) 6) Inferior orbital fissure (--\> orbit, carries _infraorbital n_.)

Question 50

Where does V2 exit the skull and what are its major branches?

Answer 50

V2 exits through foramen rotundum into the pterygopalatine fossa (PPF). * _infraorbital nerve_, tranverses the PPF anteriorly, gets to skin via *infraorbital fissure* * _descending palatine nerve_, traverses the PPF inferiorly, goes through the *palatine canal* and branches. one goes to soft palate, one goes to hard palate * _nasopalatine nerve,_ traverses the PPF superiorly, goes through *sphenopalatine foramen* into the nasal cavity * _pharyngeal nerve_ traverses the PPF posteriorly, goes through the *pharyngeal canal* to innervate the nasopharynx PNS from CN VII (_greater petrosal n.)_ synapses on the pterygopalatine ganglion and travel to the palatine (via. the _descending palatine n._), nasal (via. _nasopalatine n._) lacrimal (via. communicating branch (all PNS fibers) of _zygomaticofacial n._ to the lacrimal n. of V1) and pharyngeal glands (via _pharyngeal n._)

Question 51

Outline the innervation of the glands of the head and neck

Answer 51

**Lacrimal**: VII--\>greater petrosal n.--\> communicating branch of zygomaticofacial--\>lacrimal n. **Parotid**: IX --\> lesser petrosal --\> otic ganglion--\> Glands below oral fissure **Pharyngeal, palatine, nasal glands**: VII--\> greater petrosal n.--\> PP ganglion --\> pharyngeal, descending palatine and nasopalantine branches of V2 **Glands below oral fissure**: VII--\> chorda typani in petrotemporal groove--\>lingual nerve--\> submandibular ganglion

Question 52

How does the greater petrosal nerve get from the brainstem to the pterygopalatine fossa?

Answer 52

Exits with CN VII (lateral pontemedullary junction), goes with VII through the interal acoustic meatus at the petrous part of the temporal bone. The greater petrosal comes out of the bone, joins with postganglionic SNS fibers to form "the nerve of the pterygoid canal". It is supported by cartilage in the foramen lacerum and moves anteriorly to the pterygoid canal --\> pterygopalatine fossa. N.B: wikipedia says greater petrosal nerve (PNS form VII) and SNS together are "the nerve of the pterygoid canal

Question 53

What are the various compartments of the neck? What structures are contained in the carotid sheath?

Answer 53

clinical correlate: infxn can spread in the retropharyngeal space Carotid sheath: jugular vein, common carotid artery, vagus

Question 54

Where are the greater and lesser cornu of the hyoid? How does the hyoid move when swallowing?

Answer 54

The hyoid bone anteriorly and superiorly- it pulls the larynx forward and up so that food only goes in the pharynx

Question 55

Relationship of internal and external carotids to SCM and to cervical lymph nodes

Answer 55

Internal carotid: runs medial and deep to SCM. Has deep cervical nodes External carotid: runs external and along the lateral border of SCM. Have superficial cervical chain surrounding it

Question 56

What are the infrahyoid muscles? What are they innervated by....

Answer 56

AKA "Strap muscles" (named for lower --\> higher attachement) * Thyrohyoid * Sternothyroid * Sternohyoid (most supeficial) * Omohyoid (omo=scapula) \*\*act to depress hyoid\*\*

Question 57

What are the suprahyoid muscles? What do they do? What are they innervated by?

Answer 57

They iniate swallowing by pulling the pharynx up and posteriorly (elevate hyoid). * mylohyoid: forms floor of mouth (**V3**- think of it as a muscle of mastication) * digastric (anterior and posterior bellies, runs through "central tendon", posterior belly attaches near mastoid process) (anterior belly **V3** via mylohyoid nerve; posterior belly **VII)** * genio-hyoid (**hypoglossal nerve)** * stylohyoid (attaches on styloid process of temporal bone) (**VII)**

Question 58

Just a nice figure

Question 59

What is the relationship of the sublingual and submandibular glands to the suprahyoid muscles?

Answer 59

Wraps around the mylohyoid muscle. Lingual nerve passes underneath the submandibular duct.

Question 60

Where are the jugulo-digastric and jugulo-omohyoid nodes?

Answer 60

Question 61

What are the important cartilages of the larynx?

Answer 61

The median crico-thyroid ligament (not labelled) is what is cut in emergency ariway opening (=cricothyrotomy)

Question 62

Where is the isthmus of the thyroid gland? (landmarking)

Answer 62

A fingerwidth below the cricoid cartilage

Question 63

Where are the parathyroid glands in relation to the thyroid?

Answer 63

On the posterior surface

Question 64

What is the blood supply of the thyroid?

Answer 64

Superior (from internal carotid) and Inferior thyroid artery (from common carotid) Inferior thyroid vein

Question 65

What is the innervation of the larynx?

Answer 65

From vagus: * The _recurrent laryngeal nerves_ (the left loops around the aorta, the right loops around the r. subclavian artery). They pass underneath th inferior thyroid artery and can be injury during surgery. Injury results in *hoarseness* * The _superior laryngeal n._ splits into _internal_ and e**_xternal_**. External gives voice tone by tilting the cartilage. Injury results in *monotone voice (?dysprosody)*

Question 66

What spinal level does the common carotid bifurcate?

Answer 66

C3

Question 67

Landmark for facial artery pulse?

Answer 67

just anterior to the masseter

Question 68

Arteries given off by the external carotid

Answer 68

Maxillary is the one after facial

Question 69

What spinal segments contribute to the cervical plexus? The brachial plexus?

Answer 69

Cervical plexus: C1-C4 * phrenic nerve (C3,4,5) * _ansa cervicalis_ (C1,2,3,): innervates most of the hyoid muscles. _superior root of ansa_ (C1,2) runs with the _hypoglossal nerve_ (but the two fibers do not mix) and _inferior root of ansa_ (C2,3) * _Puntum nervosum_ is where all the sensory branches of the cervical plexus emerge. It is along the posterior border of the SCM and this is where you would inject a local

Question 70

What are the extrinsic muscles of the tongue (that we need to know), what does each do and where does it attach

Answer 70

Extrinsic tongue muscles: * genioglossus: from hyoid to genu of mandible * hyoglossus: all along the border of hyoid to join genioglossus in the midline, tilts tongue side to side * styloglossus: styloid process of temporal bone and fuses with the genioglossus. Retracts tongue.

Question 71

What is the innervation and blood supply of the tongue?

Answer 71

Innervation: * motor: hypoglossal (XII) * general sensory: anterior 2/3 lingual n. branch of V1, posterior 1/3 is glossopharyngeal * special sensory: anterior 2/3 chorda tympani (branch of VII) via lingual nerve, posterior 1/3 is glossopharyngeal Blood supply * deep lingual vein * lingual artery (from ext. carotid)

Question 72

What are the circular muscles of the pharynx?

Answer 72

Circular (x 3) * Constrictors aid in peristalsis. Attach in different places anteriorly, but posteriorly come together in the *pharyngeal raphe* which attaches to the *pharyngeal tubercle of the skull* * superior * middle * inferior

Question 73

What are the longitudinal muscles of the pharynx?

Answer 73

Longitudinal muscles (x3) * **stylopharyngeus**: attaches to styloid process of temporal bone and joins with constrictor fibers anteriorly * **palatopharyngeus**: from soft palate to constrictor fibers anteriorly * **salpingopharyngeus**: from eustachian tube (latin: salpinx) to constrictor fibers anteriorly

Question 74

Where does the pharyngotympanic tube run?

Answer 74

AKA eustachian tube runs from middle ear to pharynx. salpingopharyngeal m. stretches the tube and helps equalize pressure. Also important route for otitis media.

Question 75

Nasopharynx: * Pharygeal branch of **V2,** from pterygopalatine fossa (pharyngeal canal), does GSA Oropharynx: * Pharyngeal branch of **IX** (glossopharyngeal) does GSA and motor to _stylopharyngeus m_. only Laryngopharynx * pharyngeal and laryngeal branches of **vagus** do GSA and motor to all pharyngeal muscles *except stylopharyngeus* * (*N.B: gag reflex is IX in, X out)

Question 76

What are the muscles of the soft palate?

Answer 76

They look like a spider, with the body being the soft palate and four legs going up (2x tensor, 2x levator) and down (2 x palatopharyngeal, 2x palatoglossus) (veli is latin for soft) * **tensor veli palatini m.**: attaches at the base of the skull on both sides, comes staright down then does a 90 degree turn around the amulus of the medial pterygoid plate. Contraction flatttens the soft palate * **levator veli palatini m.** originates from the base of the skull and inserts in the midline of the soft palate. elevates soft palate * **palatopharyngeal m.** from soft palate to pharynx * **palatoglossus m.**

Question 77

What muscles form the pharyngeal arches? What is found between the arches?

Answer 77

Palatoglossus arch (anterior) and palatopharyngeal arch (and muscles) .

Question 78

What is the innervation of the soft palate muscles?

Answer 78

Vagus does all except **tensor veli palatini**. (the only one that doesn't actually move the palate....)

Question 79

What is Waldeyer's ring

Answer 79

The ring of tonsils around the pharynx...

Question 80

What is an adenoid?

Answer 80

Swollen pharyngeal tonsil...can obstruct airway in children.

Question 81

What is the epiglottis? What is it's function? What is the quandrangular membrane?

Answer 81

A flap of tissue that folds down on the larynx to block food from entering the larynx. The lower edge is attached to the _quandrangular membrane_. The quandrangular membrane itself has a free edge where mucosa folds over forming the _false vocal folds_. The _true vocal folds_ in inferior to that and are mucosa folded over the free edge of the _crico thyroid ligament_ (the one you cut in cricothyrotomy). The mucosa balooned out between the false and true vocal folds is called _the laryngeal ventricle._ The true vocal folds produce sound, the false vocal folds close during swallowing

Question 82

What is the flat muscle just deep to the skin in the neck?

Answer 82

platysma

Question 83

Mnmonic for branches of external carotid ?

Answer 83

Some: superior thyroid a. Lovers: lingual a. Fornicate: facial a. On : occipital a. Soft: superficial temporal Mattresses: maxillary/middle meningeal