Anatomy of Head and Neck

Arteries

1. Blood supply of face:

Image result for External carotid artery branches
Blood supply of face

  • External carotid artery branches ^^
  • Ophthalmic artery branches: supratrochlear, supraorbital

2. Ophthalmic artery:

  • 1st branch of internal carotid artery
  • Through optic canal
  • Runs in medial wall of orbit
  • Branches:
  1. Lacrimal
  2. Central retinal
  3. Supratrochlear
  4. Supraorbital

3. Maxillary artery:

  • Branch of external carotid artery, arises behind neck of mandible

1st part (mandibular):

  • Passes between mandible ramus and sphenomandibular ligament
  • Branches:
  1. Deep auricular
  2. Anterior tympanic
  3. Inferior alveolar
  4. Middle meningeal
  5. Accessory meningeal

2nd part (pterygoid):

  • Passes between 2 heads of lateral pterygoid muscle and enters pterygoid fossa
  • Branches:
  1. Masseteric
  2. Deep temporal
  3. Pterygoid
  4. Buccal

3rd part (pterygomaxillary):

  • Lies in pterygopalatine fossa
  • Branches:
  1. Sphenopalatine artery
  2. Greater and lesser palatine arteries
  3. Posterior superior alveolar artery
  4. Pharyngeal artery
  5. Infraorbital artery

4. Facial artery:

  • Emerges in carotid triangle from external carotid artery (ECA)
  • Deep to mandible ramus
  • Superficial to masseter and buccinator
  • Ascends lateral nose
  • Becomes angular artery
  • Branches:
  1. Superior labial
  2. Inferior labial
  3. Lateral nasal
  4. Angular

5. Subclavian artery:

  • Right one arises from brachiocephalic artery, left one arises from arch of aorta
  • It is divided into 3 parts as it passes posterior to anterior scalene muscle
  • Branches:
  1. 1st part – Vertebral, internal thoracic, thyrocervical
  2. 2nd part – Superior intercostal, deep cervical
  3. 3rd part – Dorsal scapular
  • Continues as axillary artery at border of 1st rib

6. Common carotid artery:

  • Right from brachiocephalic trunk, left from arch of aorta
  • Bifurcates into ECA and ICA at superior border of thyroid cartilage

7. External carotid artery:

  • Formed from common carotid artery
  • At upper border of thyroid cartilage
  • Outside carotid sheath
  • Posterior to ramus of mandible
  • Terminates as superficial temporal and maxillary artery

8. Vertebral artery:

  • From subclavian artery 1st part
  • Through vertebral triangle
  • Ascend in transverse foramina C6-C1
  • Enter cranial cavity via foramen magnum
  • Joins other side’s vertebral artery to form basilar artery at base of pons

Veins

1. Venous drainage of face

Venous drainage of face

2. Facial vein:

  • Tributaries: Supraorbital and supratrochlear drain into angular vein
  • Becomes facial vein
  • Superficial to masseter, buccinator and mandible
  • Joins anterior division of retromandibular vein
  • To form common facial vein
  • Drains into IJV

3. External jugular vein (EJV):

  • Formed from retromandibular vein, posterior division and posterior auricular vein
  • Forms at angle of mandible
  • Pierce deep fascia
  • Drain into subclavian vein

4. Internal jugular vein (IJV):

  • Formed from sigmoid sinus and inferior petrosal sinus
  • Through jugular foramen
  • Runs in carotid sheath
  • Unites with subclavian vein to form brachiocephalic vein
  • Tributaries: Common facial, lingual, pharyngeal, superior and middle thyroid veins

5. Subclavian vein:

  • Continuation of axillary vein from border of 1st rib
  • Anterior to scalenus anterior muscle
  • Joins IJV and EJV to form brachiocephalic vein

Nerves

1. Nerve supply to face:

  • Motor – facial nerve branches
  • Sensory – trigeminal nerve and nerves C2, C3, C4

2. Inferior alveolar nerve:

  • Branch of V3
  • Gives off a branch – mylohyoid nerve (mylohyoid and anterior diagastric muscle)
  • Between mandible ramus and medial pterygoid muscle
  • Enters mandible foramen, through mandible canal
  • Through inferior dental plexus
  • Gives off a mental nerve (at mandibular 2nd premolar) which exits via mental foramen (sensory to chin and lower lip)
  • Continues as mandibular incisive nerve to innervate mandibular canines and incisors

Clinicals:

  • Inferior alveolar nerve block – anesthesia near mandibular foramen
  • Injury – 3rd molar removal, dental implants, root canal

3. Lingual nerve:

  • Branch of V3
  • Chorda tympani nerve (of facial nerve) joins lingual nerve
  • Between mandible ramus and medial pterygoid muscle
  • Inferior to 3rd molar
  • Runs between hyoglossus muscle and deep part of submandibular gland
  • Crosses lateral to medial over Wharton’s duct
  • Runs along tip of tongue becoming sublingual nerve, lying beneath mucous membrane

Clinical: 3rd molar surgery – injury to nerve

4. Cervical plexus:

Anterior rami C1-C4 – in carotid triangle

Image result for cervical plexus

5. Gustatory pathway:

Gustatory pathway


Waldeyer’s ring

Waldeyer's ring of tonsils

Palatine tonsils:

  • Location: Between palatoglossus and palatopharyngeus folds
  • Relations:
  1. Anterior – palatoglossus fold
  2. Posterior – palatopharyngeus fold
  3. Superior – soft palate
  4. Inferior – tongue
  5. Lateral – superior constrictor
  • Blood supply:

Image result for palatine tonsils blood supply

  • Nerve: Glossopharyngeus nerve, lesser palatine nerve (V2)

Clinicals: Tonsillitis, tonsilectomy


Temporomandibular joint (TMJ)

Lateral pterygoid muscle attatches to TMJ capsule – slide forward movement

Classification: Synovial modified hinge

Lined by: Fibrocartilage

Articular surfaces: Condyle, mandibular fossa and articular tubercle of squamous temporal

Image result for temperomandibular fossa
temperomandibular joint

Stability factors:

Static:

  • Mandibular fossa and posterior glenoid tubercle
  • Articular disc – attaches to internal surface of joint capsule, dividing it into superior and inferior cavity
  • Condyle head more convex antero-posteriorly than medial to lateral
  • Lateral pole more anterior than medial
  • Ligaments:
  1. Lateral ligament – from articulating eminence to posterior condyle, prevents extreme retrusion
  2. Lateral and medial collateral ligament
  3. Sphenomandibular ligament – from sphenoid spine to lingula, prevents extreme protrusion
  4. Stylomandibular ligament – from styloid process to angle of mandible

Image result for TMJ ligaments

Dynamic: Muscles of mastication

Blood supply: Superficial temporal and masseteric arteries

Nerve supply: Auriculotemporal and masseteric

Movements: Rotation, Protraction

Relations:

  • Anterior – lateral pterygoid muscle
  • Posterior – parotid gland
  • Lateral – parotid gland
  • Medial – spine of sphenoid
  • Superior – middle cranial fossa
  • Inferior – maxillary artery

Glands

(I) Lacrimal gland:

Blood supply: Lacrimal artery from opthalmic artery

Nerve supply:

Image result for innervation of lacrimal gland


(II) Parotid gland:

Relations:

  • Superior – zygomatic arch
  • Inferior – mandible angle
  • Anterior – masseter muscle
  • Posterior – sternocleidomastoid muscle (SCM)
  • Roof – skin and fascia
  • Floor – masseter, SCM, mandible ramus

Stenson’s duct course: Anterior to masseter, pierce buccinator, open in vestibule next to 2nd maxillary molar

Pierced by: Superficial temporal artery, retromandibular vein, facial nerve

Blood supply: Superficial temporal artery

Venous: Retromandibular vein

Nerve supply: 

Image result for nerve supply parotid gland

  • Parasympathetic: Lesser petrosal nerve
  • Sympathetic: Superior cervical ganglion

Lymphatic drainage: Posterior and preauricular lymph nodes

Type of secretion: Serous

Clinicals:

  • Parotid gland tumor
  • Parotiditis – inflammation
  • Mumps

(III) Submandibular gland:

Location: Submandibular triangle

Relations:

  • Superior – mylohyoid line
  • Inferior – diagastric tendon
  • Anterior – mental foramen
  • Posterior – mandible angle
  • Medial – root of tongue
  • Lateral- masseter and mandible

Wharton’s duct course: Through 3 muscles (mylohyoid, hyoglossus, genioglossus) ⇒ crossed by lingual nerve ⇒ opens near frenulum

Nerve supply: 

  • Parasympathetic: Vasodilation
  • Sympathetic: Vasoconstrict, therefore enzyme rich mucous

Image result for submandibular gland nerve supply

Lymphatic drainage: Submandibular lymph nodes, which drain to jugulodiagastric lymph nodes

Type of secretion: Serous and mucous (seen as demilunes in histology)

Clinicals:

  • Submandibular excision – damage lingual and facial nerve
  • Calcified stones – due to ascending duct, serous and mucous secretions, and it’s a long duct

(IV) Sublingual gland:

Location: Sublingual fossa above mylohyoid line

Relations:

  • Superior – mucous membrane of mouth
  • Inferior – mylohyoid muscle
  • Posterior – submandibular gland
  • Medial – genioglossus muscle
  • Lateral- sublingual fossa

Blood supply, venous drainage, nerve supply and lymph nodes – same as submandibular gland

Type of secretion: Mucous – sublingual papilla

Clinicals:

  • Ranula – mucous cysts in floor of mouth

(V) Thyroid gland:

Location: Anterior neck, below laryngeal prominence

Extent: C5-T1

Relations:

  • Anterior – sternohyoid, sternothyroid
  • Posterior – trachea
  • Superior – cricothyroid cartilage
  • Inferior – 5 tracheal rings
  • Medial – esophagus
  • Lateral – carotid sheath

Blood supply: Superior, middle, inferior thyroid artery and vein

Nerves:

  • Sympathetic: Cervical sympathetic ganglions (superior, middle, inferior)
  • Parasympathetic: Vagus nerve

Lymphatics: Pretracheal, paratracheal and prelaryngeal lymph nodes

Pretracheal, paratracheal and prelaryngeal lymph nodes

Clinicals:

  • Goiter – enlarged thyroid gland
  • Thyroidectomy – surgical removal
  • Tracheotomy – forming an opening into trachea due to sudden obstruction of vital airways
  • Laryngoscopy

Muscles

(I) Extraocular muscles:

Image result for extraocular muscles and levator palpebrae superioris

Blood supply: Ophthalmic artery

Nerve supply: Oculomotor, Trochlear (superior oblique), Abducens (lateral rectus)


(II) Muscles of mastication:

Image result for muscles of mastication

Image result for muscles of mastication origin and insertions


(III) Suprahyoid muscles:

Image result for suprahyoid muscles

Suprahyoid muscles origin, insertion and action


(IV) Infrahyoid muscles:

Infrahyoid muscles

Infrahyoid muscles origin, insertion, action and nerve supply

Infrahyoid muscles origin, insertion, action and nerve supply


(V) Sternocleidomastoid (SCM):

  • Origin: 2 heads – manubrium, medial 1/3 clavicle
  • Insertion: mastoid process
  • Innervation: CN 11
  • Action: Turn head opposite side, raise thorax
  • Relations:
  1. Anterior – platysma muscle
  2. Posterior – carotid sheath
  3. Medial – ansa cervicalis
  4. Lateral – subclavian artery

(VI) Scalenus anterior:

  • Origin: Transverse process C3-C6
  • Insertion: 1st rib, scalene tubercle
  • Innervation: Anterior rami C4-C6
  • Relations:
  1. Anterior – SCM, subclavian vein
  2. Posterior – 2nd part subclavian artery, brachial plexus
  3. Medial – 1st part subclavian artery
  4. Lateral – 3rd part subclavian artery, brachial roots

Clinicals: Scalenus anterior syndrome – hypertonic muscle, compresses structures


Spaces

(I) Orbit:

Boundaries:

Image result for orbit boundaries
Boundaries of orbital cavity

Foramens/fissures and their contents:

Contents of foramen and fissures in orbital cavity

Orbit contents: Extraocular muscles and ciliary ganglion


(II) Temporal fossa:

Image result for temporal fossa boundaries and contents


(III) Infratemporal fossa:

Infratemporal fossa boundaries

Contents: Lateral and medial pterygoid muscles, maxillary artery, mandibular nerve, otic ganglion


(IV) Pterygopalatine fossa:

Image result for pterygopalatine fossa boundaries

Pterygopalatine fossa

Clinicals: Ligate sphenopalatine artery to stop nose bleeding


(V) Neck triangles:

(A) Anterior neck triangles

Boundaries:

Anterior neck triangle boundaries

NB: Submandibular, Carotid and Muscular triangle are paired. Submental triangle is the only unpaired triangle.

Contents:

Submental triangle:

  1. Submental lymphnodes

Submandibular (diagastric) triangle:

  1. Hypoglossal nerve
  2. Nerve to the mylohyoid
  3. Marginal mandibular branch of the facial nerve (MMB)
  4. Facial and lingual arteries and veins
  5. Submandibular gland
  6. Lower pole of the parotid gland
  7. Submandibular lymph nodes

Carotid triangle:

  1. Common carotid artery (and its bifurcation into ECA & ICA)
  2. Arteries: Superior thyroid, lingual, facial, occipital, and ascending pharyngeal arteries
  3. Veins: Superior thyroid, lingual, facial, ascending pharyngeal, and occipital veins – Drain into IJV
  4. Nerves: Hypoglossal nerve, the external and internal branches of the superior laryngeal nerve arising from the vagus nerve

Muscular triangle:

  1. Muscles: Sternohyoid, sternothyroid, omohyoid, and thyrohyoid muscles
  2. Superior thyroid artery
  3. Anterior jugular and inferior thyroid veins
  4. Ansa cervicalis
  5. Anterior cervical, infrahyoid, prelaryngeal, thyroid, pretracheal, paratracheal lymph nodes
  6. Medial part: Esophagus, trachea, thyroid gland, and the lower part of the larynx.

(B) Posterior neck triangles

Boundaries:

boundaries of posterior triangle

  • Roof: Investing fascia
  • Floor: Anterior, middle and posterior scalene muscles

Image result for occipital and subclavian triangles
Subdivisions of posterior triangle of neck

Contents:

  1. Occipital: Brachial roots, cervical plexus, occipital artery
  2. Subclavian: Subclavian artery and vein, EJV, brachial plexus trunks

(VI) Interscalene triangle:

  • Boundaries: Anterior scalene, middle scalene, 1st rib
  • Contents: Subclavian artery, brachial plexus roots

(VII) Suboccipital triangle:

Boundaries:

Image result for Suboccipital triangle

Contents: Vertebral artery, suboccipital venous plexus

Clinicals: Angiography of circle of Willi’s


Nasal cavity:

Image result for nasal cavity

Extent: Vestibule to nasopharynx

3 parts: Vestibule, olfactory region, respiratory region

Functions: 

  • Humidify air – rich vascular supply
  • Conchae slow down air
  • Prevent pathogens
  • Smell
  • Drain paranasal sinus

Boundaries:

  • Superior – ethmoid and sphenoid bone
  • Inferior – palatine bone
  • Medial – septa
  • Lateral – conchae

Below superior, middle and inferior conchae are meati (openings)

Image result for sphenoethmoidal recess
Lateral wall and openings of paranasal sinuses

Openings in the meati:

  • Above superior conchae/ sphenoethmoidal recess – Sphenoidal sinus
  • Superior meatus – Posterior ethmoidal sinus
  • Middle meatus – Frontal, maxillary and anterior ethmoidal sinus
  • Inferior meatus – Auditory tube, nasolacrimal duct

Other openings:

  • Cribriform plate – olfactory nerves
  • Sphenopalatine foramen (connects pterygopalatine fossa) – sphenopalatine artery, nasopalatine nerve
  • Incisive canal (connects oral cavity) – nasopalatine nerve to oral cavity

Blood supply:

  • Internal carotid artery: Anterior and posterior ethmoidal via cribriform plate
  • External carotid artery:
  1. Maxillary artery – Sphenopalatine, greater palatine
  2. Facial artery – Superior labial, lateral nasal

Venous: Ophthalmic vein, angular vein, sphenopalatine vein

Nerves:

  • Smell – olfactory
  • General sensory – nasopalatine, nasociliary (V2)

Clinicals: Spread of respiratory infection to ear


Paranasal sinuses:

Paranasal sinuses

  • Air filled extensions of nasal cavity
  • Reduce weight of skull
  • Humidify air
  • Are paired
  • Are mucous lined

Paranasal sinus relations, blood supply, venous, nerves, lymphatics, at birth

Clinicals:

  • Sinusitis
  • Inflammation of maxillary sinus – tooth ache
  • Rhinitis – inflamed nasal mucosa
  • Epistaxis – nose bleed (trauma or hypertension)

Tongue:

4 types of papillae:

Papillae of tongue

  1. Filiform – all over the tongue, only type that contain no taste buds
  2. Fungiform – mushroom shaped, concentrated on tip of tongue
  3. Foliate – found on postero-lateral surface of tongue
  4. Circumvallate – 12 to 14, anterior to sulcus terminalis, Von Ebner’s glands open in it

Extrinsic muscles:

Image result for extrinsic muscles of tongue

Image result for extrinsic muscles of tongue and their function

Intrinsic muscles:

Intrinsic muscles of tongue, origin and functionIntrinsic muscles of tongue, origin and action

Blood supply: Lingual artery and vein

Nerve supply:

  • Taste: Anterior 2/3 chorda tympani nerve, Posterior 1/3 glossopharyneal nerve
  • General sensation: Anterior 2/3 Lingual nerve (V3), Posterior 1/3 glossopharyneal nerve
  • Motor:  Hypoglossus nerve, except palatoglossus muscle which is supplied by vagus nerve

Lymphatic drainage: Superior deep cervical, inferior deep cervical, submandibular, submental lymph nodes

Image result for lymphatic drainage of tongue

Clinicals:

  • Tongue tie
  • Cancer
  • Halitosis – bad breath
  • Oral thrush

Hard palate and soft palate

Soft palate muscles:

Image result for soft palate muscles table

Blood supply:

Hard palate: Greater palatine artery (from descending palatine)

Soft palate:

  • Greater/ lesser palatine (from maxillary artery)
  • Ascending palatine (from facial artery)
  • Ascending pharyngeal (from ECA)

Veins: Drain into pterygoid venous plexus

Nerves: 

Hard palate:

  • Greater palatine – mucosa of posterior hard palate (from pterygopalatine ganglion, descends through greater palatine foramen with greater palatine artery)
  • Nasopalatine – anterior mucosa (through incisive foramen)

Soft palate:

  • Pharyngeal plexus via vagus nerve
  • Except tensor veli palatini – medial pterygoid nerve (V3)
  • Sensory – Lesser palatine nerve

Lymphatic drainage:

Hard palate: Submandibular, superior deep cervical nodes

Soft palate: Retropharyngeal, superior deep cervical nodes

Clinicals:

  • Cleft palate
  • Palatal abscesses
  • Cleft uvula
  • Pimples on hard palate

Pharynx

Extent: Base of skull to C6

Layers:

  1. Buccopharyngeal fascia
  2. Muscular layer – outer circular, inner longitudinal
  3. Pharyngobasilar fascia
  4. Submucosa
  5. Mucosa
  6. Surface epithelium

Muscles:

Muscles of pharynx

Muscles of pharynx - Origin, insertion and action

Blood supply:

Image result for pharynx blood supply

Nerve:

Motor:

  • Glosopharyngeal – Stylopharyngeus muscle
  • Vagus – Rest of pharynx muscles

Sensory:

  • Nasopharynx – Maxillary (V2)
  • Oropharynx – Glossopharyngeal
  • Laryngopharynx – Vagus

Lymphatics: Upper and lower deep cervical lymph nodes, retropharyngeal nodes

Clinicals: 

  • Tonsillitis
  • Pharyngeal diverticulum – cricopharyngeus does not relax, food accumulates, dysphagia
  • Tumors – dysphagia, dysphonia

Nasopharynx, oropharynx, laryngopharynx

Image result for pharynx divisions

Parts of pharynx
Nasopharynx, oropharynx, Laryngopharynx extents, relations, contents


Larynx

Parts of larynx

  • Phonation
  • Cough reflex
  • Protect respiratory tract

Extent: C3-C6

Relations:

  • Anterior – infrahyoid muscles
  • Posterior – trachea
  • Lateral – thyroid lobes

Made of 6 cartilages: (all are hyaline cartilage except epiglottis)

Single:

  • Thyroid – has laryngeal prominence
  • Cricoid – encircles completely at C6
  • Epiglottis – elastic cartilage

Paired:

  • Arytenoid
  • Corniculate
  • Cuneiform

Ligaments/membranes:

Extrinsic:

  • Thyrohyoid membrane – pierced by internal laryngeal nerve and superior laryngeal vessels
  • Median cricothyroid ligament
  • Cricotracheal ligament

Intrinsic:

  • Cricothyroid/vocal ligament
  • Quadrangular ligament

NB: Vocal opening – Rima glottidis

Blood supply:

  • Superior laryngeal artery(from superior thyroid artery) – runs with internal laryngeal nerve
  • Inferior laryngeal artery(from inferior thyroid artery) – runs with recurrent laryngeal nerve

Venous:

  • Superior laryngeal – drains in superior thyroid
  • Inferior laryngeal – drains in inferior thyroid

Nerves:

Sensory:

  • Infraglottis – Recurrent laryngeal
  • Supraglottis – Internal laryngeal

Motor:

  • Cricothyroid muscle – External laryngeal
  • All other muscles – Recurrent laryngeal

Sympathetic: Middle and inferior cervical sympathetic ganglia

Clinicals:

  • Cricothyroidotomy- Make temporary airway
  • Laryngitis
  • Laryngectomy
  • Laryngoscopy
  • In puberty, boy’s cartilage enlarge, vocal folds become thicker
  • Old age – ligament and cartilage ossify


Others

1. Horner’s syndrome:

Image result for Horner's syndrome:


2. Deep fascia of neck:

Deep fascia of neck


3. Structures in midline of neck:

Hyoid bone ⇒ Thyrohyoid membrane ⇒ Thyroid cartilage ⇒ Cricothyroid membrane ⇒ Cricoid cartilage ⇒ Cricotracheal ligament ⇒ Tracheal rings

Image result for cartilages in midline of neck

NB: Internal laryngeal artery and superior laryngeal vessels pierces thyrohyoid membrane


4. Carotid body and carotid sinus:

Arteries of neck
Carotid body, carotid sinus


5. Parts of mandible:

Image result for parts of mandible


6. External and internal auditory meatus:

External and internal auditory meatus extent

EAM to tympanic cavity:

  • Blood supply: Posterior auricular, superficial temporal
  • Nerve: Great auricular, auriculotemporal

IAM:

  • Blood supply: ascending pharyngeal
  • Nerve: Glossopharyngeal

Clinicals:

  • Otitis – ear inflammation
  • Mastoiditis – middle ear infection

These are summarized notes from various sources, mainly TeachMeAnatomy and Wikipedia