Head and Neck Flashcards

1
Q

Bony Orbit: Gross Anatomy

A

The orbit is a feature of the face and contains the globe

Has a roof, floor, medial and lateral wall - four sided pyramid with the apex posterior and the base forming the orbital margin

Orbit open anterior, but bound by the orbital septum

Communicates with the intracranial compartment via the optic canal and superior orbital fissure

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2
Q

Bones of the orbit

A

The bony orbit is made up of:

  • Maxillary bone
  • Lacrimal bone
  • Ethmoid bone
  • Zygomatic bone
  • Frontal bone
  • Orbital process of the palatine bone
  • Greater and lesser wings of the sphenoid
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3
Q

Spaces of the Orbit

A
  • Globe
    • divided into anterior and posterior chambers by the lens
    • parts: lens, iris, sclera, choroid, retina, vitreous humour
  • Extraconal space contents
    • fat
    • lacrimal gland and sac
    • inferior opthalmic vein and portion of the superior ophthalmic vein
    • extraconal branches of the opthalmic artery (eg. lacrimal artery) - initially intraconal then becomes extraconal
  • Conal space contents
    • extraocular muscles (LR, MR, SR, IR, SO, IO)
    • interconnecting fascia
  • Intraconal space
    • formed by the posterior half of the globe and the sides are formed by the extraocular muscles which pass posteriorly and converge on the tendinous ring at the orbital apex
    • contents
      • orbital fat
      • intraconal branches of the ophthalmic artery
      • superior ophthalmic vein
      • cranial nerves III, IV, V1, VI
  • Optic nerve-sheath complex
    • optic nerve
    • ophthalmic artery
    • central retinal artery (branch of opthalmic artery) and vein
    • surrounding sheath of meninges as an extension of the cerebral meninges
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4
Q

Communication with the orbit

A
  • Optic canal to intracranial cavity
  • Superior orbital fissure also to the intracranial cavity
  • Inferior orbital fissure to infratemporal fossa
  • Anterior ethmoidal foramen
  • Posterior ethmoidal foramen
  • Supra and infra orbital foramen
  • Nasolacrimal foramen
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5
Q

Ethmoid Sinus: Description

A

The ethmoid air cells form one of the four pairs of paranasal sinuses.

Location: within the midline ethmoid bone between the orbits

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6
Q

Ethmoid Sinus: Gross Anatomy

A
  • 3-18 air cells separated by bony septa within each lateral mass of the ethmoid bone
  • The air cells are separated into anterior and posterior by the basal lamella, the lateral attachment of the middle concha
  • The anterior ethmoid air cells drain the hiatus semilunaris and middle meatus
  • The posterior ethmoid air cells drain the superior meatus and sphenoethmoidal recess
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7
Q

Ethmoid Sinus neurovasculature

A
  • Blood supply: Ophthalmic, anterior and posterior ethmoidal arteries
  • Lymphatic drainage: submandibular and retropharyngeal nodes
  • Innervation: anterior and posterior ethmoid nerve from the nasociliary nerve, a branch of the ophthalmic division of the trigeminal nerve.
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8
Q

Ethmoid Sinus Variants

A
  • Agger nasi cells – anterior most air cells located inferior to the frontal recess 90% of patients, actually located in the lacrimal bones
  • Ethmoid bulla – largest and most consistently found air cell located in the roof of the middle meatus
  • Haller cells – infraorbital air cells found in 20 percent of patients
  • Onodi cells – posterior most ethmoid air cell, that lies superior to the sphenoid sinus ~30%
  • Concha bullosa – middle turbinate pneumatisation
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9
Q

Maxillary Sinus: Description

A
  • Paired pyramid shaped sinuses in the maxillary bone
  • Function: lighten the head, vocal resonance
  • Location: body of the maxilla
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10
Q

Maxillary Sinus: Gross anatomy

A
  • They are the largest of the paranasal sinuses.
  • Pyramid with base in the lateral boarder of the nose with apex pointing toward the zygomatic process of the maxilla. The floor is formed by the alveolar section of the maxilla, the roof forms the floor of the orbit.
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11
Q

Maxillary Sinus: Drainage

A

Via the maxillary ostium medial superior point of the pyramid, into the infundibulum, draining into the hiatus semilunaris, then into the middle meatus.

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12
Q

Maxillary Sinus: Neurovasculature

A

Blood supply:

  • Supplied by branches of the facial, maxillary, infraorbital and greater palatine arteries.
  • Venous drainage is via the sphenopalatine veins and the pterygoid plexus

Lymphatic drainage:

  • Submandibular group

Innervation:

  • Superior alveolar nerves
  • Greater palatine nerves
  • Infraorbital nerves
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13
Q

Maxillary Sinus: Variants

A
  • Concha bullosa
  • Haller cells – infraorbital air cells
  • Agger nasi cells – most anterior ethmoidal air cells
  • Silent sinus syndrome
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14
Q

Ostiomeatal Complex: Description

A

Is the common drainage pathway for the frontal, maxillary and anterior ethmoid air cells. Drains to the middle meatus in lateral nasal wall allowing airflow and mucocillary drainage. Important unit for the ENT surgeons.

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15
Q

Ostiomeatal Complex: Gross Anatomy

A

5 parts:

  • Maxillary Os.: opening within the medial superior maxillary sinus and drainage channel for maxillary sinus.
  • Infundibulum: Common channel that drains the maxillary os. and anterior ethmoid cells to hiatus semilunaris.
  • Ethmoid Bulla: Single ethmoid air cell that sits over the hiatus
  • Uncinate Process: hook like bony projection of arising from the nasolacrimal duct that leads to the anterior boundary of hiatus
  • Hiatus Semilunaris: Final drainage passage; a region between the ethmoid bulla superiorly and free-edge of the uncinate process
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16
Q

Ostiomeatal Complex: Neurovasculature

A

Artery:

anterior and posterior ethmoid artery

Sphenopalatine artery

Nerve:

Greater and lesser palatine N

Vein:

Inferior ophthalmic V and facial V

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17
Q

Ostiomeatal Complex: Variants

A
  • concha bullosa: aerated middle turbinate
  • intralamellar cell: air cell within vertical portion of middle turbinate
  • oversized ethmoid bulla (Agger nasi cells)
  • Haller cells (infraorbital cells)
  • uncinate process bullae
  • deviation of uncinate process
  • deviated nasal septum
  • paradoxical middle turbinate: convexity of turbinate directed toward lateral nasal wall
  • ethmoidal bulla may not be pneumatised, and be a bony prominence
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18
Q

Frontal Sinuses: Description

A

The frontal sinuses are the paranasal sinuses of the frontal bone

Function: lighten the head, vocal resonance

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19
Q

Frontal Sinuses: Gross Anatomy

A
  • Lined with mucosa
  • Highly variable however there are typically bilateral sinuses extending within the frontal bone between the inner and outer table from the gleballa to the mid to upper forehead
  • Three or more chambers may be present
  • Divided by a thin bony intrasinus septa
  • Drainage: Drains via the frontal recess into either:
    • Ethmoidal infundibulum, through the hiatus semilunaris and into the middle meatus
    • Directly into the middle meatus
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20
Q

Frontal Sinuses: Neurovasculature

A

Blood supply:

Supratrochlear

Anterior ethmoidal

Supraorbital arteries

Venous drainage:

Superior ophthalmic veins

Lymphatic drainage:

  • Submandibular nodes
  • Skin overlying to the pre-auricular nodes
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21
Q

Frontal Sinuses: Relations

A
  • Anterior: Outer table of the frontal bone, frontalis muscle
  • Posterior: Inner table of the frontal bone, the frontal lobe
  • Lateral: Supraorbital foramen
  • Medial: Intersinus septa
  • Inferior: Nasal cavity
  • Superior: Frontal eminance
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22
Q

Frontal Sinuses: Variants

A
  • Aggar nasi air cells
  • Complete absence
  • Silent Sinus syndrome
  • Mucosal polyps
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23
Q

Mandible: Description

A

The mandible is a large single midline bone of the lower face

Function: respiration, verbalisation, mastication

Location: Jaw

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24
Q

Mandible: Gross Anatomy

A

Irregular bone. It consists of a curved horizontal portion the body and two perpendicular portions, the rami. The rami and the body unite at almost right angles (the angle of the jaw).

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25
Q

Mandible: Features

A

Body:

  • Mandibular symphysis – midline point of fusion
  • Mental foramen - inferior to the second pre-molar (mental vessels and nerve, the terminal branches of the inferior alveolar vessels and nerves)
  • Fossae for the sublinguinal and submandibular glands
  • Alveolar process of the teeth
  • Groove for the facial artery of the inferior boarder

Ramus:

  • Mandibular foramen – opening of the mandibular canal, which transmits the inferior alveolar vessels and nerves
  • Coronoid process – anteriorly
  • Condylar process – posterior
  • Mandibular notch – space between the above two
  • Mandibular canal – between the mandibular foramen and the mental foramen

Coronoid Process

  • Separated from the condylar process by the mandibular notch
  • Temporalis muscle insert into its medial and lateral surfaces
  • Masseter muscle also inserts to its lateral surface

Condylar Process

  • Consists of two portions - condyle and neck
  • Articulates with the articular disk of the TMJ, in the mandibular fossa of the temporal bone
  • Lateral pterygoid muscle inserts into condylar neck
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26
Q

Mandible: Articulation

A
  • Gomphosis joints with the lower row of teeth
  • Temporomandibular joint – between the condylar process of the mandible and the mandibular fossa and the articular eminence of the temporal bone. Atypical synovial joint with a fibrocartilage articular disc
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27
Q

Mandible: Ligaments

A

Temporomandibular ligaments

Stylomandibular ligaments

Sphenomandibular ligaments

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28
Q

Mandible: Neurovasculature:

A

Blood supply:

Facial, lingual and inferior alveolar arteries and nerves

Lymphatics:

Submandibular

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29
Q

Ossicular Chain: Description

A

There are three ossicles (from lateral to medial):

  • malleus
  • Incus
  • Stapes

Their role is to mechanically amplify the vibrations of the tympanic membrane and transmit them to the cochlea where they can be interpreted as sound. They are located in the middle ear cavity and articulate with each other via tiny synovial joints.

Interestingly, they are the only bones in the body that do not grow after birth.

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30
Q

Malleus

A
  • Most lateral, latin for hammer
  • Head, neck, handle, anterior and lateral processes
  • Lateral process is connected to the tympanic membrane
  • Anterior process small anchoring fibres
  • Handle – attachment of the tensor typani (origin cartilaginous part of the eustachian tube, supplied by the mandibular nerve)
  • Head – articulates with the incus
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31
Q

Incus

A
  • Body, long crus and short crus
  • Latin for anvil
  • Body articulates with the head of the Malleus
  • Short crus posterior ligament of the incus
  • Long crus articulates with the stapes
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32
Q

Stapes

A
  • Likes like a stirrup, is latin for stirrup
  • Base plate sits on oval window
  • Anterior and posterior arches
  • Neck in the union of the anterior and posterior arch
  • Neck articulates with the incus
  • Stapedius attaches to the neck (innervated by the facial nerve)
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33
Q

Temporal Bone: Description

A

The temporal bone is an important calvarial and skull base bone and is highly complex with multiple articulations

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34
Q

Temporal Bones: Gross Anatomy

A
  • Squamous – This flat portion is the external to the temporal lobe and is the lateral part of the skull.
  • Petrous – Pyramidal in shape, forms the posterior part of the middle cranial fossa, inner ear organ are located within
  • Mastoid – pneumatised by the mastoid air cells, posterior to the ear, serves as an attachment point for SCM
  • Tympanic – Bony of the external acoustic canal, inferior surface forms the mandibular fossa for TMJ, zygomatic process for formation of the zygomatic arch
  • Styloid- Slender pointed process form the inferior anterior temporal bone which is an anchor point for muscles of tongue and larynx: Styloglossus, stylohyoid muscle and ligament, stylomandibular lig, stylopharyngeus m
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35
Q

Temporal Bone: Articulation

A
  • Occipital bone
  • Sphenoid
  • Zygomatic
  • Parietal
  • Mandible via TMJ
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36
Q

Temporal Bone: Variants

A

Short and long styloid process

Calcified stlylohyoid ligament – eagles syndrome compression cranial nerve or ICA

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37
Q

Temperomandibular joint: Description

A

Bilateral joint of the jaw. Modified hinge joint.

Function: Mastication, verbalisation, respiration

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38
Q

TMJ: Anatomy

A

The temporomandibular joint (TMJ) is an atypical synovial joint located between the condylar process of the mandible and the mandibular fossa and articular eminence of the temporal bone.

It is divided into a superior discotemporal space and inferior discomandibular space by the TMJ disc (or meniscus).

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39
Q

TMJ: Movement

A
  • upper compartment: protraction, retraction and gliding side-to-side
  • lower compartment: opening and closing
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40
Q

TMJ: Ligaments

A
  • temporomandibular
  • stylomandibular
  • sphenomandibular
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41
Q

TMJ: Muscles

A
  • Medial and lateral pterygoids
  • Masseter
  • Temporalis
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42
Q

TMJ: Neurovasculature

A

Arterial:

Superficial temporal

Vein:

Retromandibular

Innervation:

  • auriculotemporal nerve
  • masseteric nerve
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43
Q

Extra-ocular muscles: Description

A

The extra-ocular muscles are the six muscles that insert onto the eye and hence control eye

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44
Q

Extraocular muscles: Gross Anatomy

A
  • superior rectus: elevation, annulus of Zinn to the superior globe
  • superior oblique: intorsion, sphenoid bone via catelaginous trochlear to superior lateral globe
  • medial rectus: adduction, annulus of Zinn to the medial globe
  • lateral rectus: abduction, annulus of Zinn to the lateral globe
  • inferior oblique: extorsion, Maxillary bone to inferior lateral globe
  • inferior rectus: depression, annulus of Zinn to the inferior globe
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45
Q

Extra-ocular muscles: innervation

A

oculomotor nerve:

  • superior, medial, and inferior rectus
  • inferior oblique

trochlear nerve:

  • superior oblique

abducens nerve:

  • lateral rectus
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46
Q

Extra-ocular muscles: vasculature

A

Arterial supply:

  • Primarily form opthalmic artery and branches
  • Lacrimal artery (branch of opthalmic artery) supplies lateral rectus
  • Inferior oblique and interior rectus receive branches of the infraorbital artery

Venous

  • Sup opthalmic vein -> cavernous sinus
  • Inf opthalmic vein -> pterygoid plexus -> Emmisary veins to cavernous sinus AND joint superficial temporal vein to become retromandoibular vein
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47
Q

Muscles of Mastication: Description

A

The primary muscles of mastication are: the temporalis, massester, medial and lateral pterygoids. The suprahyoid muscles assist with mastication.

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48
Q

Temporalis

A
  • Origin : Infratemporal fossa
  • Insertion: coronoid process and ramus of mandible, tendon passes deep to the zygomatic arch.
  • Action: Elevate and retract the mandible, as well as lateral translation
  • Blood: Maxillary artery
  • Nerve: Deep temporal nerve from mandibular N (CNV3)
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49
Q

Masseter

A
  • Multipennate arrangement of fibres, can be palpated when clench teeth together at side of cheeks.
  • Origin: Zygomatic arch is origin
  • Insertion: Inserts laterally on the ramus and angle of the mandible
  • Action: elevates and protract the mandible
  • Blood: Masseteric branch of maxillary artery, superficial temporal and facial
  • Nerve: Mandibular nerve from anterior division of CNV3
  • Has three layers
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50
Q

Lateral Pterygoids

A
  • Divided into 2 parts:
    • The superior part:
      • Origin: greater wing of the sphenoid
      • Insertion: TMJ capsule and disc
    • The inferior part
      • Origin: lateral surface of the lateral pterygoid plate
      • Insertion: the pterygoid fovea, neck of the mandible
  • Innervation: nerve to the lateral pterygoid from the mandibular nerve
  • Blood: pterygoids branches of the maxillary artery
  • Action: Jaw opening and retraction
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51
Q

Medial Pterygoids

A

Medial Pterygoids

  • Origin: 2 heads, one from the medial surface of the lateral pterygoid plate and the other head is from the palatine bone
  • Insertion: medial surface of the ramus
  • Nerve: medial pterygoid nerve from the mandibular nerve
  • Blood: maxillary artery
  • Action: closes mouth, elevates and protrude the jaw
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52
Q

Muscles of mastication: Variants

A
  • Muscle hemihypertrophy/hemiatrophy
  • Altered insertion of origin
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53
Q

Arteries of the nasal cavity

A
  • Sphenopalatine
  • Anterior ethmoidal
  • Posterior ethmoidal
  • Superior labial
  • Greater palatine
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54
Q

Sphenopalatine artery

A

Origin: maxillary artery third part

Course: Through the sphenopalatine foramen, into the sphenopalatine recess

Supplies: Posterior walls and nasal septum

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55
Q

Posterior ethmoidal artery

A

Origin: Branch on the ophthalmic artery

Course: Through the posterior ethmoidal foramen

Supplies: Posterior wall, ethmoid and sphenoid sinuses

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56
Q

Anterior ethmoidal artery

A

Origin: Branch of the ophthalmic

Course: enters the nose through the anterior ethmoidal foramen

Supplies: anterior wall, anterior ethmoidal sinuses and frontal sinuses

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57
Q

Superior labial artery

A

Origin: branch of the facial artery

Course: Ascends up the lip enters the nose though the posterior nare

Supplies: anterior wall and septum, lip

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58
Q

Greater Palatine Artery

A

Origin: branch of the maxillary artery

Course: enters the nose via the incisive foramen

Supplies: hard palate

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59
Q

Anastamosis of nasal plexus

A

Kisselbach plexis:

  • vascular region of the anteroinferior nasal septum that comprises four arterial anastomoses:
    • anterior ethmoidal artery
      • a branch of the ophthalmic artery
    • sphenopalatine artery
      • a branch of the maxillary artery
    • greater palatine artery
      • a branch of the maxillary artery
    • superior labial artery (septal branches)
      • a branch of the facial artery

Woodruff’s plexus: posterior anastomosis of the sphenopalatine, posterior ethmoidal and ascending pharyngeal arteries, posterior nasal packing is required to stop epistaxis here

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60
Q

Ophthalmic artery: Gross Anatomy

A

Origin: From the ophthalmic (C6) division of the internal carotid artery, arises medial to the anterior clinoid process as the ICA exits the cavernous sinus

Course: Anterior through the suprasella cistern, courses below the optic nerve, enters the orbit by the optic canal. Cross over the optic nerve from medial to lateral

Termination: bifurcation as the supratrochlear and dorsal nasal arteries

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61
Q

Ophthalmic artery: Branches (9)

A
  • Orbital group (ASSLIP)
    • lacrimal artery
    • supraorbital artery
    • posterior ethmoidal artery
    • anterior ethmoidal artery
    • internal palpebral artery
    • supratrochlear artery
    • dorsal nasal artery
  • Ocular group (CLAMS)
    • central retinal artery
    • long posterior ciliary arteries
    • short posterior ciliary arteries
    • anterior ciliary artery
    • muscular artery
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62
Q

Ophthalmic artery: variants

A
  • Communication with the middle meningeal artery via the sphenoidal artery
  • Meningo-orbital foramen
  • Complete orbital supply by the middle meningeal artery
  • Cavernous origin of the ophthalmic artery
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63
Q

Extracranial Facial nerve: Description

A

The seventh cranial nerve carries motor for the muscles of facial expression. Also relay taste and parasympathetics in a complex manner

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64
Q

Extracranial facial nerve: Gross anatomy

A
  • Exits the stylomastoid foramen and gives of the posterior auricular nerve
  • Passes between the posterior belly of the digastric and the stylohyoid muscle, supplying both
  • Enters the parotid gland
  • Between the deep and superficial lobes it divides into its five main branches:
    • Temporal
    • Zygomatic
    • Buccal
    • Mandibular
    • Cervical

These branches are in reality a complex nerve network.

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65
Q

CN VII: Temporal branch

A

The temporal branch runs over the zygomatic arch. This branch is at risk during surgery in this region.

Motor to facial muscles above the orbits

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66
Q

CNVII: Zygomatic branch

A

Motor to orbicularis oculi

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67
Q

CNVII: Buccal Branch

A

Motor to muscles around the mouth

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68
Q

CNVII: Mandibular branch

A

The mandibular branch, in 80% of cases, runs along the lower border of the mandible (thus also referred to as marginal branch). In 20% of cases however it can be up to 2 cm below the margin of the mandible.

Motor to mouth depressors

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69
Q

CNVII: Cervical Branch

A

Motor to platysma

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70
Q

CNVII: Variants

A

Corda tympani may branch after the nerve has exited the stylomastoid foramen

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71
Q

Nasolacrimal apparatus: Description

A

The nasolacrimal apparatus is the system responsible for drainage of tears. Production of tears by the lacrimal gland is included in some text under this heading.

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72
Q

Lacrimal gland Gross Anatomy

A
  • Location in the superior lateral orbit in the extraconal space
  • Almond shaped
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73
Q

Lacrimal Apparatus: Gross anatomy

A

Location: From the medial canthus to the inferior concha

Consists of:

  • Lacrimal canaliculi which drain the lacrimal lake via the lacrimal puncta
  • Lacrimal sac – the superior and inferior lacrimal canaliculi drain into the lacrimal sac which lies in the lacrimal fossa, it drains into the nasolacrimal duct via the valve of Krause, the sac is enclosed in the lacrimal fascia and the orbicularis oculi
  • Nasolacrimal duct – Is the inferior continuation of the lacrimal sac, it is approximately 17mm in length, it has 2 parts: intraosseous part which lies within the nasolacrimal canal of the maxilla, the membranous part which runs in the nasal mucosa. It terminates below the inferior nasal meatus as a slit like opening where it is covered by a mucosal fold called the valve of Hasner
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74
Q

Nasolacrimal Apparatus: Neurovasculature

A

Artery: lacrimal artery from the ophthalmic artery

Vein: Superior ophthalmic vein

Nerves: greater petrosal nerve (from facial nerve) and lacrimal nerve (ophthalmic division of the trigeminal nerve)

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75
Q

Nasolacrimal apparatus: Relations

A
  • Medial: the maxilla
  • Lateral: Lacrimal lake
  • Superior: Superior orbital rim
  • Inferior: Floor of the nasal cavity
  • Posterior: ethmoid labyrinth and nasal cavity
  • Anterio-medial: Nasal vestibule
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76
Q

Nasolacrimal Gland Variants

A
  • Incompetent valve of Hasner
  • Absence
  • Accessory glands
  • Draining to the middle meatus
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77
Q

Tympanic Membrane: Description

A

The tympanic membrane is a thin membrane that separates the external ear from the middle ear. It acts to transmit sound waves from air in the external auditory canal (EAC) to the ossicles of the middle ear.

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78
Q

Tympanic membrane: Gross description

A

The tympanic membrane is shaped like a flat cone pointing into the middle and inner ear. At the centre of the concavity the deepest point is called the umbo.

It attaches to an incomplete ring of bone along the wall of the EAC, the tympanic annulus. It consists of three layers (from external to internal):

  • cutaneum (skin)
  • radiatum circulare (collagen fibres)
  • mucosum (epithelium)

There are two distinct portions of the membrane:

  • pars tensa: the tense portion of the membrane is the larger portion inferior to the anterior and posterior malleolar folds
  • pars flaccida: the flaccid portion of the membrane is much smaller and is the portion of the membrane above the anterior and posterior malleolar folds

Quadrant separation:

It is anatomically separated into four quadrants:

  • anterosuperior
  • anteroinferior
  • posteroinferior
  • posterosuperior
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79
Q

Tympanic Membrane: Relations

A
  • Anterior – TMJ
  • Posterior – mastoid process
  • Superior – Tegmen typani and epitympanic recess
  • Inferior – Jugular bulb
  • Medial – Eustachian tube, ossciles and tympanic cavity
  • Lateral – EAM and ear
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80
Q

Tympanic membrane: Vasculature

A

Arterial Supply:

  • Branches of the maxillary artery

Veins:

  • External jugular
  • Transverse sinus
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81
Q

Tympanic Membrane: Innervation

A
  • external surface
    • predominantly the auriculotemporal nerve (CN V3)
    • greater auricular nerve (C2, C3)
  • internal surface:
    • tympanic branch of the glossopharyngeal nerve (CN IX)
82
Q

Extra-ocular spaces of the orbit: spaces

A

The orbit is a space of the anterior face

Function:

  • Contain the globe and associated support structures and organs
  • Passage of nerve arteries and veins
83
Q

Orbit: Relations

A
  • Superior: frontal bone, and anterior fossa
  • Inferior: Maxillary sinus
  • Lateral: infratemporal space
  • Medial: ethmoidal air cells
  • Posterior: the cavernous sinuses
  • Anterior: Superior and inferior palabra
84
Q

Nasopharynx: Description

A

The nasopharynx forms the superior most part of the pharynx. It is in continuity with the inferior oropharynx and the posterior continuation of the anterior nasal cavity.

85
Q

Nasopharynx: Boundaries

A
  • Anterior: posterior nasal apertures
  • Posterior: adenoids, superior pharyngeal constrictor muscle, longus coli, longus capitis, clivus of the occipital bone, c1 and c2 vertebrae
  • Inferiorly: the soft palate
  • Superior: basisphenoid, basiocciput, sphenoid sinus
  • Laterally: The pharyngeal opening of the Eustachian tube (torus tubaris), tubal tonsil, fossa of Rossenmuller
86
Q

Nasopharynx: Neurovasculature

A

Arterial:

  • Ascending pharyngeal artery
  • Ascending palatine branch of the facial artery
  • Ascending cervical artery
  • Maxillary artery

Venous:

  • Pterygoid plexus (external jugular)
  • Pharyngeal plexus (internal jugular)

Lymphatic drainage:

  • Waldeyer’s ring

Innervation:

  • Sensory: Pharyngeal nerve (maxillary division of the trigeminal nerve) and the glossopharyngeal nerve
  • Motor: Vagus
87
Q

Nasopharynx: Muscles

A
  • Tensor veli palatine
  • Lavator veli palatine
88
Q

Pterygopalatine fossa: Description

A

Small complex space of the deep face.

Location: Posterior to the posterior wall of the maxillary sinuses, anterior to the pterygoid process

Function: Passage of many structures to and from multiple anatomical spaces

89
Q

Pterygopalatine fossa: Boundaries

A
  • Anterior: Posterior wall of the maxillary sinus
  • Posterior: sphenoid bone
  • Lateral: Pterygomaxillary fissure
  • Medial: Perpendicular plate of the pterygoid
  • Superior: Orbital apex
  • Inferior: pyramidal process of the palatine bone
90
Q

Pterygopalatine fossa: Communication

A
  • Nasal cavity
  • Oral cavity
  • Infratemporal fossa
  • Orbit
  • Middle cranial fossa
  • Pharynx
  • Masticator space
91
Q

Pterygopalatine fossa: Contents

A
  • Pterygopalatine ganglion
  • Terminal third of the maxillary artery
  • Maxillary nerve
92
Q

Superior orbital Fissure:Description

A

The superior orbital fissure is the communication between the cavernous sinus and the apex of the orbit. It is straddled by the tendinous ring which is the common origin of the four rectus muscles (extraocular muscles).

93
Q

Superior orbital fissure: Boundaries

A
  • medial: body of sphenoid
  • superior: lesser wing of sphenoid
  • inferior: greater wing of sphenoid
  • lateral: frontal bone
94
Q

Superior orbital fissure: Contents

A
  • L: lacrimal nerve (branch of CN V1)
  • F: frontal nerve (branch of CN V1)
  • T: trochlear nerve (CN IV)
  • S: superior division of the oculomotor nerve (CN III)
  • N: nasociliary nerve (branch of CN V1)
  • I: inferior division of the oculomotor nerve (CN III)
  • A: abducens nerve (CN VI)
95
Q

Middle ear cavity: Description

A

It is a 6 walled oval cavity with sits between the tympanic membrane and the inner ear in the petrous temporal bone and contains the ossicles for conduction of hearing

Function:

Transmit the sound of hearing into the cochlea which allows sense of hearing

96
Q

Middle ear: Relations

A
  • Anterior wall – carotid canal
  • Posterior wall – mastoid air cells
  • Superior wall ­- tegmen tympani, middle cranial fossa
  • Medial wall – labyrinth
  • Lateral wall – tympanic membrane
  • Inferior – internal jugular bulb
97
Q

Middle ear: Contents

A
  • Auditory ossicular chains
  • Tensor tympani
  • Stapedius
  • Chorda tympani
98
Q

Middle ear: Neurovasculature

A

Innervation:

  • Tympanic branch of glossopharyngeal (jacobson’s N)
  • Chorda tympani

Artery:

Branches from the maxillary artery

Venous:

Pterygoid venous plexus

Lymphatic:

Via the parotid, retropharyngeal and upper deep cervical nodes of the neck

99
Q

Middle ear: Variants

A

Aberrant ICA – Petrous ICA which gives a pulsatile retrotympanic mass

100
Q

Inner ear: Description

A

A set of complex structures within the medial petrous bone

Function: Conversion of sound to nerve impulses, acceleration and rotational sense

101
Q

Inner ear: Gross anatomy

A

The bony labyrinth contains the membranous labyrinth

Parts:

  • Cochlea – 2.5 times spiral, contains the organ of conti, which converts auditor signals to nerve impulses, starts at the oval window, end with the round window
  • Saccule and utricle – linear acceleration sensory organs
  • Semicircular canals – x3 lateral, posterior and superior, rotation sense
102
Q

Inner ear: Relations

A

Anterior: Geniculate ganglion

Posterior: internal acoustic meatus

Lateral: middle ear

Medial: petrous apex

103
Q

Inner ear: Neurovasculature

A

Arterial supply:

Labyrinthine artery

Anterior tympanic artery

Venous drainage:

Pterygoid plexus

Nerves:

Vestibulocochlear

Facial

104
Q

Inner ear: Variants

A

Aberrant ICA

Congenital absence of the cochlear nerve

Labyrinthine artery can be from the AICA or basilar artery

105
Q

Hyoid: Description

A

The hyoid is a “horseshoe-shaped” bone that serves as a structural anchor in the mid-neck. It is the only bone in the human body that does not directly articulate with another bone, sesamoids aside. The location of structures in the neck are often described in terms of relation to the hyoid (i.e. suprahyoid neck; infrahyoid neck).

Function: Pharyngeal phase of swallowing.

106
Q

Hyoid: Gross anatomy

A

Location: midline neck, anterior to the trachea, the level of the hyoid separates levels II from III in the lateral neck and levels Ia and VI in the anterior neck

Consists of:

  • a body
  • two greater horns
  • two lesser horns
107
Q

Hyoid: arterial supply

A

branches of external carotid artery and superior thyroid artery

108
Q

Hyoid: Attachments

A

Body:

  • suprahyoid muscles
    • mylohyoid muscle
    • geniohyoid muscle
    • digastric muscles
    • stylohyoid muscle
  • infrahyoid (strap) muscles
    • omohyoid muscle
    • sternohyoid muscle
    • thyrohyoid muscle

greater horn:

  • hyoglossus muscle
  • middle pharyngeal constrictor muscle

lesser horn:

  • stylohyoid ligament (i.e. no muscular attachment)
109
Q

Hyoid: Relations

A

The position of the hyoid defines a few lymph node levels of the neck. Anteriorly, the hyoid separates levels Ia (above) from VI (below). Laterally, the level of the hyoid separates level II from level III.

110
Q

Constrictors of the pharynx

A

The constrictor muscles of the pharynx are a set of 3 pharyngeal constrictors that constrict the pharynx to deliver a bolus of food to the oesophagus.

Type: skeletal muscles under semi-voluntary control

111
Q

Superior pharyngeal constrictor

A
  • Origin: pterygoid hamulus, pterygomandibular raphe and mandible
  • Insertion: Pharyngeal raphe
  • Artery: ascending pharyngeal artery, branch of the external carotid artery
  • Nerve: pharyngeal plexus from vagus
112
Q

Middle Pharyngeal constrictor

A
  • Origin: Greater and lesser conu of the hyoid bone
  • Insertion: Pharyngeal raphe
  • Artery: Ascending pharyngeal artery (external carotid artery)
  • Nerve: pharyngeal plexus from vagus
113
Q

Inferior pharyngeal constrictor

A
  • Origin: Cricoid and thyroid cartilage
  • Insertion: Pharyngeal raphe
  • Artery: Ascending pharyngeal artery
  • Nerve: pharyngeal plexus from vagus
  • Incorporates cricopharyngeus inferiorly
114
Q

Pharyngeal constrictors: Relations

A
  • Anterior – pharynx
  • Posterior – Cervical spine vertebrae and retropharyngeal space
  • Lateral – carotid sheath and it’s contents
  • Superior – base of the skull
  • Inferior – Cricopharyngeus muscle
115
Q

Pharyngeal Constrictors:Variants

A
  • Cricopharyngeal bar
  • Zenker’s diverticulum
116
Q

Scalenus Anterior: Description

A

The scalenus anterior (also known as anterior scalene) is a neck muscle and known as the “key” structure for the thoracic inlet as it is an important anatomical landmark.

117
Q

Scalenus anterior: Gross anatomy

A

origin: transverse processes of 3rd to 6th cervical vertebrae

insertion: inner border of first rib (scalene tubercle)

blood supply: ascending cervical artery

innervation: ventral rami of cervical nerves C4-C7

Function: raises first rib (inspiration) adjunct: neck rotation/flexion

118
Q

Scalenus anterior: Relations

A

Anteriorly:

  • phrenic nerve, vagus nerve
  • internal jugular vein, subclavian vein
  • sternocleidomastoid muscle, omohyoid muscle
  • clavicle

Posterior:

  • second portion of subclavian artery (which is divided in three parts by the muscle)
  • scalenus medius muscle
  • Cervical plexus

Medially:

  • common carotid artery
  • first portion of subclavian artery
  • thyrocervical trunk
  • vertebral artery and vein
  • thoracic duct (left) or right lymphatic duct (right)

Laterally:

trunks of brachial plexus

third portion of subclavian artery

119
Q

Scalenus Anterior: Variants

A
  • Compression of subclavian artery and brachial plexus between the anterior and medial scalenes
  • Cervical rib
120
Q

Sternocleidomastoid Muscle

A

The sternocleidomastoid (SCM) is a muscle of the neck. It has two heads that meld to form one insertion. SCM, along with the trapezius muscle, is invested by the superficial layer of the deep cervical fascia, which splits around it. SCM divides the neck into anatomical anterior and posterior triangles.

121
Q

SCM: Gross Anatomy

A

origin: manubrium (sternal head – tendinous), medial clavicle (clavicular head – muscular)

insertion: mastoid process of the temporal bone, superior nuchal line of the occipital bone

Artery: Superior thyroid and occipital arteries

innervation: accessory nerve (CN XI)

action: lateral flexion, flexion and rotation of the head on the neck, raise sternum (secondary muscle of respiration).

122
Q

SCM: Relations

A

upper half:

anteriorly: platysma muscle, external jugular vein

Medial: anterior scalene muscle, common carotid artery, internal jugular vein, carotid sheath

lower half:

anteriorly: platysma
posteriorly: anterior scalene muscle, common carotid artery, internal jugular vein, carotid sheath

123
Q

SCM: Variants

A
  • absent mastoid insertion (occipital insertion only)
  • absent clavicular or sternal head
  • fusion with trapezius muscle
  • additional clavicular head
  • separate muscle bellies for sternomastoid and cleidomastoid
  • separate muscle bellies for cleidooccipital and sternocleidomastoid
124
Q

External Carotid artery: Description

A

The primary blood supply to the face and neck

125
Q

ECA: Gross anatomy

A

Origin:

  • Bifurcation of the common carotid (level of C4)

Course:

  • Begins at the level of the upper border of the thyroid cartilage (level of C4)
  • Slightly curved course upwards and anteriorly before inclining backwards to the space behind the neck of the mandible
  • Along its course, it rapidly diminishes in size and as it does so, gives of various branches
  • As it enters the parotid gland, it gives rise to its terminal branches
  • Lies deep to facial nerve and retromandibular vein within the parotid

Termination: bifurcation in the maxillary and superficial temporal artery

Distinguishable from ICA due to the many branches of the ECA

126
Q

Branches of the ECA

A
  • Superior thyroid artery
  • Ascending laryngeal
  • Lingual
  • Facial
  • Occipital
  • Posterior auricular
  • Maxillary
  • Superficial temporal
127
Q

Relations of ECA

A
  • Anteriorly (ie. ECA is crossed by these structures)
    • upper root of ansa cervicalis
    • hypoglossal nerve (CN XII)
    • posterior belly of digastric muscle
    • stylohyoid muscle and ligament
    • facial nerve (CN VII) (within the parotid gland)
  • Passing between ECA and ICA
    • pharyngeal branch of vagus nerve (CN X)
    • glossopharyngeal nerve (CN IX)
    • stylopharyngeus muscle
    • styloglossus muscle
  • Posteriorly (ie. ECA lies on these structures)
    • pharyngeal wall
    • superior laryngeal branch of vagus nerve (CN X)
    • deep lobe of the parotid gland
128
Q

Variants of the ECA

A
  • Branch height

Trunks:

  • Lingofacial trucnk
  • Thryolingual
  • Thyrolingualfacial
  • Occipital and posterior auricular have common trunk
129
Q

Vertebral artery: Description

A

The vertebral arteries are paired arteries that form the primary blood supply to the posterior circulation of the brain.

Origin: Typically, the first branch of the first part of the subclavian artery

130
Q

Vertebral artery: Course

A

Dividable in 4 parts:

  • Pre-foraminal:
    • From the subclavian
    • through the thoracic outlet
    • between longus colli and scalenus anterior,
    • behind the common carotid
    • to the foramina transversarium of C6
  • Foraminal – ascending through the transversarium foramina to the C2 transverse foramina
  • Extra-dural:
    • From C2 transverse foramina
    • Lateral to pass through the transverse foramen of C1
    • Loops posteriorly around the lateral masses
    • Pierces the dura
  • Intra-dural – ascending either side of the medulla to unite and form the basilar artery in the pre-pontine cistern at the base of pons
131
Q

Vertebral artery: Relations

A
  • Key relation: Posterior to the internal carotid artery, ascends anterior to the roots of the hypoglossal nerve
132
Q

Vertebral artery: Branches

A
  • Radicular/spinal branches
  • Posterior inferior cerebellar artery
  • Anterior and posterior meningeal arteries
  • Anterior and posterior spinal arteries
133
Q

Vertebral artery: Variants

A
  • Sided dominance is common hypoplastic sided
  • Termination of one side into the PICA
  • Aplasia
  • Duplication
  • Fenestration
  • Aberrant origin: branch of subclavian but not the first or aortic origin or brachiocephalic origin (on the right) or external carotid
134
Q

Jugular veins: Description

A

There are 4 paired jugular veins which provide drainage of deoxygenated blood from the face, head and brain:

  • Internal jugular veins
  • External jugular veins
  • Posterior external jugular veins
  • Anterior jugular veins
135
Q

Internal jugular vein: Gross Anatomy

A

Origin:

  • Formed by the sigmoid sinus and the inferior petrosal sinus in or just distal to the jugular foramen

Course/Relations:

  • Formed by the union of inferior petrosal and sigmoid dural venous sinuses
  • Descends in the carotid sheath with the internal carotid artery
  • Vagus nerve (CN X) lies between the two
  • Receiving tributaries (Mnemonic: Medical Schools Like Confident People)
  • Descends into the thorax usually between the heads of the sternocleidomastoid muscle
  • Unites with the subclavian vein to form the brachiocephalic vein just posterior to the sternoclavicular joint
136
Q

Internal jugular vein: Tributaries

A

Tributaries:

(medical school lets fun people in)

  • Middle thyroid v
  • Superior thyroid v
  • Lingual v
  • Facial v
  • Pharyngeal v
  • Inferior petrosal sinus
137
Q

External Jugular veins: Gross anatomy

A

Origin:

  • Posterior auricular vein and posterior division of the retromandibular vein unite to form the EJV at the angle of the mandible
    • anterior division of the retromandibular vein drains into the facial vein and subsequently the IJV

Course/Relations:

  • Courses inferiorly in the subcutaneous anterolateral neck
  • Deep to platysma but superficial to the SCM
  • Pierces the deep cervical fascia posterior to the clavicular head of the SCM
  • Drain into the subclavian vein
138
Q

External jugular veins: Tributaries

A
  • Posterior external jugular vein
  • Anterior jugular vein
  • Suprascapular vein
  • Transverse cervical vein
139
Q

Anterior jugular veins

A

Origin: Arise in the region of the hyoid bone confluence of multiple submandibular vessels

Course: Descending medial to the anterior border of the sternocleidomastoid

Drains to: passes deep to SCM to drain into the external jugular vein

Tributaries: Small submandibular, laryngeal and thyroid veins

Variant: may drain directly to the subclavian veins

140
Q

Posterior jugular veins

A

Origin: Confluence of superficial veins of the posterosuperior neck and scalp

Course: Supeficial course over the posterior triangle

Drains to: External jugular vein

141
Q

Level 1 lymphatics in the neck

A

Submental and submandibular nodes

  • Below mylohyoid muscle and above the lower margin of the hyoid bone (or the carotid bifurcation)
  • anterior to the posterior border of the submandibular glands
  • level Ia: submental nodes, i.e. between the anterior bellies of the digastric muscles
  • level Ib: submandibular nodes between the anterior and posterior bellies of digastric muscles
142
Q

Level II lymphatics in the neck

A

Superior Internal jugular (deep cervical) chain

  • base of the skull to the inferior border of hyoid bone (or the carotid bifurcation)
  • anterior to the posterior border of sternocleidomastoid (SCM) muscle
  • posterior to the posterior border of the level I glands
143
Q

Level III lymphatics in the neck

A

Middle Internal jugular (deep cervical) chain

  • lower margin of hyoid to lower margin of cricoid cartilage (or the intermediate tendon of Omohyoid)
  • anterior to the posterior border of SCM
  • Posterior to the anterior border of SCM
144
Q

Level IV lymphatics in the neck

A

Inferior Internal jugular (deep cervical) chain

  • lower margin of cricoid cartilage to level of the clavicle
  • anterior and medial to an oblique line drawn through the posterior edge of SCM and the posterolateral edge of the anterior scalene muscle
  • Posterior to the anterior border of SCM
145
Q

Level V lymphatics in the neck

A

Posterior triangle (spinal accessory) nodes, posterior to posterior edges of SCM and scalenus anterior

  • level Va: superior half, posterior to levels II and III
  • level Vb: inferior half, posterior to level IV
146
Q

Level VI lymphatics in the neck

A

prelaryngeal / pretracheal / Delphian node

  • from the inferior margin of hyoid bone to the manubrium
  • anterior to levels III and IV
147
Q

Level VII lymphatics in the neck

A
  • superior mediastinal nodes
  • between CCAs, below superior aspect of manubrium to level of the brachiocephalic vein
148
Q

Cervical oesophagus: Description

A

The cervical oesophagus is the portion of the oesophagus between the oropharynx and the superior thoracic aperture

149
Q

Cervical oesophagus: Gross anatomy

A

Origin: Oropharynx, it is the first portion of the oesophagus

Course: descending in the visceral space of the neck

Termination: continues as the thoracic portion of the oesophagus at the level of the superior thoracic aperture

150
Q

Cervical Oesophagus: Neurovasculature

A

Arterial supply:

Branches of the inferior thyroid artery

Venous drainage:

Inferior thyroid veins

Innervation:

Sympathetic trunk and vagus nerves

Lymphatic:

Deep cervical nodes

151
Q

Cervical Oesophagus: Relations

A
  • Superior: oropharynx
  • Inferior: Thoracic portion of the oesophagus
  • Lateral: lobes of the thyroid, recurrent laryngeal nerves, sternocleidomastoids,
  • Anterior: thyroid strap muscles, trachea
  • Posterior: pre-vertebral fascia, vertebral body, vertebral discs
152
Q

Cervical Oesophagus: Variants

A
  • Tracheo-oesophageal fistula
  • Zenker’s diverticulum
  • Prominent cricophrangeal bar
153
Q

Larynx: Description

A

The larynx is a complex muscular-cartilaginous structure of the neck

Function: Vocalisation, respiration, swallow

Location: Within the visceral space of the neck, continuation of the oropharynx, continues as the cervical trachea, located between C3 and C6

154
Q

Larynx: Gross anatomy

A

Dividable into supraglotic and infraglottic parts

155
Q

Unpaired cartilages of the larynx

A
  • Thyroid cartilage
  • Cricoid cartilage
  • Epiglottic cartilage
156
Q

Paired cartilages of the larynx

A
  • Arytenoid cartilages
  • Corniculate cartilages
  • Cuneiform cartilages
157
Q

Muscles of the larynx

A
  • Cricothyroid
  • Vocalis
  • Thyroarytenoid
  • Posterior cricoarytenoid
  • Lateral cricoarytenoid
  • Oblique arytenoid muscles
158
Q

Larynx: Ligaments

A
  • Throhyoid membrance
  • Hyo-epiglottic ligament
  • Cricotracheal ligament
  • Meidan cricothyroid ligament
  • Cricothyroid ligament
  • Quadrangular ligament
159
Q

Larynx: Neurovasculature

A

Arterial supply:

  • Above Vocal Cords - Superior Laryngeal Artery (Branch of Superior Thyroid)
  • Below Vocal Cords - Inferior Laryngeal Artery (Branch of Inferior Thyroid)

Venous drainage:

  • Above Vocal Cords - Superior Laryngeal Veins to the Superior Thyroid Veins
  • Below Vocal Cords - Inferior Laryngeal Veins to the Inferior Thyroid Veins

Nerve supply:

  • Motor:
    • Recurrent Laryngeal Nerve
    • Except Cricothyroid muscle which is supplied by External Laryngeal Nerve (branch of the Superior Laryngeal)
  • Sensory:
    • Above Vocal Cords - Internal Laryngeal Nerve (branch of the Superior Laryngeal)
    • Below Vocal Cords - Recurrent Laryngeal Nerve

Lymphatic drainage:

  • Deep Cervical Nodes
160
Q

Larynx: Relation

A
  • Anterior: strap muscles, anterior jugular vein
  • Posterior: oesophagus, laryngophranx
  • Superior: hyoid bone, laryngopharynx
  • Inferior: trachea
161
Q

Thyroid gland: Description

A

The thyroid gland is an endocrine gland located in the pre-tracheal fascia of the neck

Function: endocrine control of metabolism

Location: Pre-tracheal fascia anterior to the thyroid, cricoid and first 3 tracheal cartilages

162
Q

Thyroid: Description

A
  • Butterfly shaped with a lobe bilaterally joined by a central isthmus
  • Each lobe may be divided into an upper and lower pole
  • Parathyroid glands lie with each pole and are sometime intracapsular
163
Q

Thyroid: Neurovasculature

A

Arterial supply:

  • Superior thyroid artery (from the ECA)
  • Inferior thyroid artery (from the thyrocervical trunk)

Venous drainage:

  • Superior, middle and inferior thyroid veins (internal jugular, internal jugular and brachiocephalic vein)

Innervation:

  • Superior, middle and inferior cervical ganglia

Lymphatics:

  • Level 6 cervical nodes
164
Q

Thyroid relations

A
  • Anterior – strap muscle
  • Posterior – thyroid and cricoid cartilage, trachea
  • Posterior medial – trachea-oesophageal groove with the parathyroid glands and the recurrent laryngeal nerves
  • Posterior lateral – carotid space
165
Q

Thyroid: Variants

A
  • Pyramidal lobe
  • Lobar hemigenesis
  • Thyroglassal duct cyst
  • Ectopic thyroid tissue – lingual thyroid
  • Zuckerkandl’s tubercle
  • Thyroidea Ima artery
166
Q

Trachea: Description

A

The trachea is the primary trunk of the conductive airways

Function: transmission of gas between the larynx and the main bronchi

Location: Visceral space of the neck and posterior mediastinum

167
Q

Trachea: Gross anatomy

A

Made up of posteriorly incomplete cartilage rings with interspaced annular ligaments

Enveloped by the trachealis muscle which is particularly prominent posteriorly

Lined with ciliated epithelium

Divided into: cervical and thoracic trachea

Origin: continuation of the airway distal to the cricoid cartilage (C6)

Termination: birfucates at the carina level T4

168
Q

Trachea: Neurovasculature

A

Arterial supply:

  • Inferior thyroid arteries
  • Bronchial arteries

Venous drainage:

  • Inferior thyroid veins
  • Azygos system

Lymphatics:

  • Drainage into deep cervical, peri and para-tracheal nodes of the mediastinum

Innervation:

  • Vagus and sympathetic trunk
169
Q

Trachea: Relations

A
  • Posterior: oesophagus and recurrent laryngeal nerve
  • Anterior: Thyroid strap muscle, jugular notch, manubrium, great vessels of the superior mediastinum
  • Lateral: Sternocleidomastoid, brachiocephalic veins and arteries
  • Superior: larynx
  • Inferior: Sub-carinal lymph nodes, main bronchi
170
Q

Trachea: Variants

A
  • Trachea oesophageal fistula
  • Tracheal atresia
  • Pig bronchus
  • Lunate trachea
  • Tracheal diverticulum
171
Q

Parotid gland: Description

A

The parotid glands are paired salivary glands

Function: production of saliva for lubrication of mastication and the initiation of digestion

Location: in the parotid space (wrapped around the mandibular ramus)

172
Q

Parotid gland: Gross anatomy

A
  • Multiple lobules draining into a central duct.
  • The duct courses over the masseters, pierces the buccinators to drain adjacent to the 1st superior molars.
  • Dividable into: deep lobe, superficial lobe and tail
  • Lymph nodes are located within the gland
  • Deep cervical fascia splits to surround the gland
  • Posteriorly the fascia forms the stylomandibular ligament
173
Q

Structures through parotid gland

A
  • Facial nerve and branches
  • External carotid artery branching to form the maxillary and superficial temporal arteries
  • Retromandibular vein
174
Q

Parotid gland: Neurovasculature

A

Arterial supply:

Parotid branches of the maxillary artery and external carotid artery

Venous drainage: via the retromandibular vein into the internal jugular veins

Innervation:

Auriculotemporal nerve and external carotid plexus

175
Q

Parotid gland: Relations

A
  • Superior: Superiofical temporal artery
  • Inferior: external carotid artery
  • Anterior: angle of the mandible
  • Posterior: exernal acoustic meatus, styloid process
  • Lateral: skin
  • Medial: carotid space
176
Q

Parotid Gland: Variants

A
  • Agenesis
  • Accessory lobe anteriorly
  • Duplicated ducts
  • Ectopic glandular tissue
177
Q

Carotid sheath: Description

A

The carotid sheath is a thick tubular fascial extension from the base of skull to the aortic arch and is one of 7 deep spaces of the neck. It is formed from the 3 layers of deep cervical fascia and fuses with the precervical fascia.

178
Q

Carotid sheath: Contents

A
  • Common carotid artery to C4 then the internal carotid artery
  • Internal jugular vein
  • Cranial nerves 9 to 12
  • Sympathetic trucnk
  • Ansa cervicalis
  • Deep cervical lymph nodes
  • Carotid body baroreceptors
179
Q

Carotid sheath: boundaries

A

Laterally: Parotic space

Medially: Visceral space

Anterior: Masticator space and parapharyngeal space

Superior: Jugular foramen

Inferior: Aortic arch

Posterior: Perivertebral space

180
Q

Carotid sheath: Relations

A

Vagus runs between the common carotid and internal jugular vein

Anteriolateral covered by SCM

Infrahyoid neck the sheath rest lateral to the thyroid

Crossed anteriorly by the posterior belly of digastric suprahyoid

181
Q

Carotid sheath: Variants

A
  • Ansa Cervicalis on outside of sheath
  • CNX descends outside sheath
  • CNX related to lateral to IJV or medial to CCA
  • Recurrent laryngeal branch travels in sheath
182
Q

Deep spaces of the neck

A

The deep anatomy is separated by fascial planes into deep compartments, and by the hyoid bone into:

  • Suprahyoid
  • Infrahyoid neck
183
Q

Spaces crossing both supra and infra hyoid neck

A
  • carotid space (post-styloid parapharyngeal space)
  • retropharyngeal space and danger space
  • perivertebral space (including prevertebral space)
184
Q

Spaces in the suprahyoid neck

A
  • parapharyngeal space (pre-styloid parapharyngeal space)
  • masticator space
  • buccal space
  • parotid space
  • sublingual space
  • submandibular space
  • pharyngeal mucosal space
185
Q

Spaces in the infrahyoid neck

A
  • anterior cervical space
  • posterior cervical space
  • visceral space
186
Q

Relations to the parapharygeal neck

A
  • parapharyngeal space lies in a central location in the deep face
  • pharyngeal mucosal space is medial to the parapharyngeal space
  • masticator space is anterior to the parapharyngeal space
  • parotid space is lateral of the parapharyngeal space
  • carotid space is posterior to the parapharyngeal space
  • retropharyngeal space is posterior to parapharyngeal space
  • perivertebral space is posterior to the retropharyngeal space
187
Q

Cervical plexus: Description

A
  • Plexus of the ventral rami of C1 to C4 cervical segments
  • Located laterally to the transverse processes and deep to the SCM
  • Between prevertebral muscles medially and vertebral muscles laterally (scalenus, levator scapulae, splenius cervicis) from lateral side
  • Anastomoses with the accessory nerve, hypoglossal nerve and sympathetic trunk
  • Branches of the cervical plexus emerge from the posterior triangle
188
Q

Cervical Plexus: Branches

A
  • Cutaneous (4 branches):
    • great auricular nerve: innervates skin near outer ear and EAM (C2-3)
    • transverse cervical nerve: innervates anterior region of neck (C2-3)
    • lesser occipital: innervate the skin and the scalp posterosuperior to the auricle (C2-3)
    • supraclavicular nerves: innervate region of supraspinatus, shoulder, and upper thoracic region (C3-4)
  • Muscular
    • ansa cervicalis (loop formed from C1-C3)
      • geniohyoid (C1), thyrohyoid (C1), sternothyroid, sternohyoid, omohyoid
    • Joined by CN XII
    • phrenic: innervates diaphragm and the pericardium (C3-C5)
    • segmental branches: innervates anterior and middle scalenes (C1-C4)
  • Two branches formed by roots of spinal nerves:
    • preauricular nerve (posterior roots of C2–C3)
    • postauricular nerve (posterior roots of C3–C4)
189
Q

Infratemporal fossa: Boundaries

A

Boundaries:

  • Medial: lateral pterygoid plate
  • Lateral: ramus of the mandible
  • Anterior: infratemporal surface of the maxillary sinus
  • Posterior: articular tubercle of the temporal bone
  • Floor: medial pterygoid muscle
  • Roof: greater wing of sphenoid
190
Q

Infratemporal fossa: Contents

A
  • Muscles
    • medial pterygoid
    • lateral pterygoid
    • temporalis
  • Arteries
    • maxillary artery
    • MMA
    • buccal
    • inferior alveolar
    • deep temporal
  • Veins
    • pterygoid venous plexus
    • retromandibular vein
  • Nerves
    • mandibular nerve (V3)
    • inferior alveolar nerve
    • lingual nerve
    • buccal nerve
    • chorda tympani nerve
    • otic ganglion
191
Q

Maxillary artery branches

A

First (mandibular) part:

Five branches, each of which enters a bony foramen:

  • deep auricular artery (enters squamotympanic fissure)
  • anterior tympanic artery (enters squamotympanic fissure)
  • middle meningeal artery (enters foramen spinosum)
  • accessory meningeal artery (enters foramen ovale)
  • inferior alveolar artery (enters mandibular foramen)
    • branch is artery to mylohyoid

Second (pterygoid or muscular) part:

Five branches although pterygoid branches are irregular in their number and origin:

  • anterior deep temporal branches
  • posterior deep temporal branches
  • pterygoid branches
  • masseteric artery
  • buccinator artery

Third (pterygopalatine) part:

Six branches including the terminal branch:

  • posterior superior alveolar artery
  • infraorbital artery (enters inferior orbital fissure)
  • artery of the pterygoid canal
  • pharyngeal artery (enters palatovaginal canal)
  • greater (descending) palatine artery (enters greater palatine foramen)
  • sphenopalatine artery - terminal branch (enters sphenopalatine foramen)
192
Q

Mandible: Variants

A

The mental foramen may be doubled or tripled

The mylohyoid groove may be bridged over by a bony process and converted into a canal

Anomalous teeth distributed throughout the mandible

193
Q

Nasal cavity: Description

A
  • The nasal cavity is formed by:
    • anteriorly: nasal aperture
    • laterally: inferior, middle and superior nasal conchae or turbinates
    • superiorly: cribiform plate of the ethmoid bone
    • inferiorly: palatal processes of the maxilla and horizontal portion of the palatine bone
  • In the midline, the nasal cavity is divided into right and left halves by a septum composed of fibrocartilage, the vomer and the perpindicular plate of the ethmoid bone
  • Anteriorly it is continuous with the nose at the nasal aperture
  • Posteriorly it is continuous with the nasopharynx
  • Laterally, the three nasal conchae form three spaces:
    • superior meatus
    • middle meatus
    • inferior meatus
194
Q

Nasal Cavity:Arterial supply

A
  • The arterial supply of the nasal cavity is rich and derives from both the internal and external carotid arteries (mnemonic: GASPS)
  • Lateral nasal wall
    • anterior and posterior ethmoidal arteries (branch of the opthalmic artery)
    • sphenopalatine artery (branch of the maxillary artery)
    • pharyngeal artery (branch of the ascending pharyngeal artery)
  • Septum
    • greater palatine artery (branch of the maxillary artery)
    • sphenopalatine artery (branch of the maxillary artery )
    • anterior and posterior ethmoid branches (branch of the opthalmic artery )
  • Floor
    • greater palatine artery (branch of the maxillary artery)
    • superior labial arteries
  • Rich arterial supply results in two anastomotic areas, which are common sites of epistaxis:
    • Woodruff area: anastomosis of sphenopalatine and pharyngeal arteries just posterior to the inferior turbinate
    • Kiesselbach plexus: anastomosis of the anterior ethmoid, greater palatine, sphenopalatine and superior labial arteries in the anteroinferior nasal septum
195
Q

Nasal cavity: Venous drainage

A

Venous plexus drains into the sphenopalatine vein, facial vein, infraorbital veins, ophthalmic veins

Note that posterior ethmoid veins anastomose with veins of the dura mater and orbit (making this a potential route of spread of infection)

196
Q

Nasal Cavity: Innervation/Lymphatics

A

Innervation:

  • CN V2: mucous membrane of the nasal septum
  • CN I: olfactory by the olfactory nerve

Lymphatic drainage:

  • Submandibular, retropharyngeal and deep cervical lymph nodes
197
Q

Orbit: Relations

A

Superior: anterior cranial fossa, frontal sinus

Medial: nasal cavity, ethmoid sinuses and sphenoid sinus

Inferior: maxillary sinus

Posterolateral: infratemporal fossa, middle cranial fossa

198
Q

Orbit: Contents

A
  • Globe
  • Extraocular Muscles
  • Nerves: Optic, branches of Oculomotor, Trochlear, Branches of Opthalmic - V1 (Frontal, Lacrimal, Nasociliary), Abducens, Sympathetic Nerves
  • Vessels: Opthalmic Artery, Superior and Inferior Opthalmic Veins
  • Lacrimal Gland
  • Orbital Fat
199
Q

Orbit: Neurovasculature

A

Blood Supply:

  • Ophthlamic Artery
  • Supraorbital Artery (branch of opthalmic artery)
  • Infraorbital Artery (branch of maxillary artery)

Venous Drainage:

  • The Superior and Inferior Ophthalmic Veins - to the Cavernous sinus and Pterygoid plexus

Nerve Supply:

  • Optic Nerve supplies the globe
  • Oculomotor Nerve: superior rectus, medial rectus, inferior rectus, inferior oblique, levator palpebrae superioris
  • Trochlear Nerve: superior oblique muscle
  • Ophthalmic Nerve (V1): function includes sensation to iris, lacrimal gland
  • Abducens Nerve: lateral rectus muscle
200
Q

Parathyroid glands: Gross anatomy

A
  • Endocrine glands located in the visceral space of the neck
  • Produce parathyroid hormone which controls calcium homeostasis
  • Normally two pairs of parathryoid glands, inferior and superior
  • Variable location from carotid bifurcation to anterior mediastinum
  • Usually in close relation to the thyroid gland, in the region of the tracheo-oesophageal groove, posterolateral to the thyroid lobes
  • The parathyroid glands are usually extracapsular to the thyroid but sometimes they may lie intracapsular
201
Q

Parathyroid Glands: Neurovasculature

A

Arterial supply:

  • Superior thyroid artery
  • Inferior thyroid artery

Venous drainage:

  • Superior thyroid vein (to IJV)
  • Middle thyroid vein (to IJV)
  • Inferior thyroid vein (to brachiocephalic)

Lymphatics:

  • Prelaryngeal lymph nodes

Innervation:

  • Middle cervical ganglion
  • Inferior cervical ganglion
202
Q

Parathyroid: Variants

A
  • Supernumerary glands
  • Absence of parathyroid glands (less than 4)
  • Ectopic parathyroid gland: most commonly inferior to the inferior pole of the thyroid
  • Parathyroid glands may be located anterior to the thyroid or be intracapsular