Mod 11 - Head and Neck

• 2 subtriangles: occipital and supraclavicular
• Nerves:
•   -CN XI
•   -Roots and trunk of brachial plexus (bw anterior and middle scalene)
•   -Long thoracic
•   -dorsal scapular
•   -phrenic
•   -more...
• Arteries: Subclavian and Suprascapular
• Veins: Subclavian and External Jugular
• Lymph Nodes: Deep and Superficial LN; Supraclavicular LN

• 1) Investing layer
• 2) pretracheal layer
• 3) Paravertebral layer
• 4) carotid sheath

• pharynx
• larynx
• esophagus
• trachea
• thyroid and parathyroid glands

• common and internal carotid
• IJV
• vagus
• deep cervical LNs
• phrenic nerve

• 1) Carotid triangle: superior belly of omohyoid 
• 2) Muscular triangle: omohyoid->digastric
• 3) Digastric triangle: Digastric to midlin of neck

• 1) Vagus nerve (always posterior)
• 2) IJV (always lateral)
• 3) Common carotid
• 4) deep LNs
• 5) ansa cervicalis embedded in anterior sheath

• 1) Spinal Acc. N
• 2) post. belly of digastric
• 3) omohyoid
• 4) AJV

terminates behind the sternoclavicular heads of SCM

• AL: skin and superficial fascia; sup. belly of omohyoid (upper end of gland); anterior border of SCM (lower end); sternothyroid and sternohyoid muscles (middle portion)
• Medially: thyroid and cricoid cartilages (upper end); upper 6 rings of trachea and esophagus; recurrent laryngeal n (lower end)
• Posteriorly: common carotid; parathyroid glands; inferior thryoid artery

superficial to the masseter (deep to transverse facial artery), dives medially into the buccal fat pat, pierces the buccinator, enters oral vestibule by 2nd maxillary molar.

• parotid gland
• facial nerve
• retromandibular vein
• external carotid artery
• parotid LNs

• superior and posterior: superior temporal line
• inferiorly: infratemporal crest
• anteriorly: frontal and zygomatic bones
• laterally: zygomatic arch
• floor: parts of pteroin bones (frontal, parietal, temporal, greater wing of sphenoid)
• roof: temporalis muscle

• Temporalis muscle.
• Deep temporal nerve (off V3).
• Deep temporal artery (off maxillary artery).
• Auriculotemporal nerve (off V3).
• Superficial temporal artery (off ECA)
• Temporal nerve (off facial nerve).

• Superior: Greater wing of sphenoid
• medial: pterygoid plate
• lateral: ramus of mandible
• anterior: posterior maxilla
• posterior: styloid process

• Lateral and medial pterygoid muscles.
• Maxillary artery (with its branches).
• Pterygoid venous plexus.
• Mandibular nerve with its branches.
• Otic ganglion.
• Chorda tympani.

• 2 large elevators (temporalis, masseter)
• 2 pterygoid muscles (lateral, medial)
• 2 tensor muscles (tympani, palatine)
• 2 muscles of floor of mouth (digastric, mylohyoid)

• 1) Outer fibrous tunic 
• 2) Vascular (uveal) tunic (middle)
• 3) Retinal (nervous) tunic (innermost)

When the sensory layer pulls away from the pigment epithelium

1)impulses from photoreceptive rod or cone to bipolar cells

2) Bipolar cells contact ganglion cells (closest to the vitreous)

• 3) The ganglion cells (~ 1 million)  send their axons (unmyelinated) to the optic
• nerve head (optic disc) where they come together as the optic nerve (now
• becomes myelinated)

• Horizontal cells
• and amacrine cells integrate the signals.

• 1) lens
• 2) aqueous humor
• 3) lens
• 4) viteous body

Either too much or a blockage of the aqueous humor

• enzymes
• lipids
• other proteins
• metabolites

Skeletal (neural crest): maxilla, mandible, zygoma, inner ear bones (incus and malleus), temp bone

muscle (paraxial): muscles of mastication, tensor tympani, ant belly of digastric, mylohyoid, tensor palatini

Innervation: trigeminal

skeletal (neural crest): stapes, styloid process, upper half of hyoid

muscular (paraxial): muscles of facial expression, stapedius, stylohyoid, post belly of digastric

innervation: facial nerve

skeletal (neural crest): lower half of hyoid

muscular (paraxial): stylopharyngeus muscle

innervation: glossopharyngeal (IX)

skeletal (neural crest): laryngeal cartilages

muscles (paraxial): pharyngeal constrictors, intrinsic laryngeal muscles, cricothyroid, levator palatini

Innervation: Vagus

• middle ear cavity
• auditory (Eustachian) tube

tonsillar fossa (palatine tonsils)

• thyroid
• inferior parathyroid

superior parathydoid

Cleft 1: external auditory meatus; external surface of tympanic membrane

Clefts 2-4: amalgamate and eventually regress

Clinical: If 2-4 fail to regress completely, you can have a painless brachial cleft cyst

1) Arch 1 forms anterior 2/3 (trigeminal), Arch 3 forms posterior 1/3 (glossopharyngeal)

2) All tongue muscles from occipital somites (Hypoglossal)

• 1) Lacrimal gland: lies in fossa in superolateral orbit. innervated by parasymp fibres from CN VII
• 2) Lacrimal ducts: go from gland to superior conjunctival fornix (latin for arch)
• 3) lacrimal canaliculi drain to lacrimal sac
• 4) lacrimal sac drains to nasal cavity via nasolacrimal duct
• 5) nasolacrimal duct

• Nasopharynx: trigeminal
• Oropharynx: glossopharyngeal
• laryngopharynx: vagus

above sup. constrictor: tensor veli palatini, levator veli palatini, auditory tube

b/n sup and mid const: stylopharyngeus muscle, stylohyoid membrane and ligament, Cn IX

b/n mid and inf const: internal branch of superior laryngeal nerve, superior laryngeal artery

Below inferior constrictor: recurrent laryngeal nerve, inferior laryngeal artery

• group of lymphoid tissue containing:
• 1) Palatine tonsils. Lymphoid tissue lying between the palatoglossal and palatopharyngeal arches.
• 2) Pharyngeal tonsils. Lymphoid tissue lying in the roof of the pharynx.
• 3) Lingual tonsils. Lymphoid tissue lying at the base of the tongue.
• 4) Tubal tonsils. Lymphoid tissue surrounding the opening of the auditory tube.

• 1) frenulum lingulae (tongue tied) at midline
• 2) deep lingual VAN on either side of midline (why you dissolve pills under the tongue)
• 3) fibriated fold (ridge of mucous membrane)

• 1) epiglottis: one end attached to thyroid cartilage, glosso- and pharyngo- epiglottic folds move it
• 2) thyroid cartilage: biggest, attached to cricoid and hyoid by membranes
• 3) cricoid cartilage (C6): ring shaped, attached to thyroid cart and trachea
• 4) arytenoid: pair of cartilages with vocal processes

• 1) plain film: face fracture, orbital injury, C spine injury
• 2) CT - acute head trauma, suspected acute intracranial hemorrhage, suspected mass or tumor, headache, mental status change
• 3) CT Agiography: stroke, aneurysms, vasculitis, congenital malformations
• 4) MRI: charact. of abnormalities seen in CT, seizure, tumor, strokes, infections, MS, post-surgical evaluation

Bones: nasal bone, frontal process of maxilla

Cartilage: Alar (tip), lateral nasal, sides (almost near midline), septal

• Roof: Nasal, frontal, ethmoid, spenoid bones
• floor: upper surface of hard palate
• medial wall: nasal septum
• lateral wall: three nasal conchae

• levator veli palatini - pharyngeal plexus
• tensor veli palatini - V3
• palatoglossus - pharyneal plexus
• palatopharyngeus - pharyngeal plexus
• muscular uvula - pharyngeal plexus

• anteriorly: to orbit via inferior orbital fissure
• laterally: to the infratemporal fossa 
• to the nasal cavity
• to the middle cranial fossa: through the foramen rotundum (V2)
• to the oral cavity:
• to the nasopharynx

• maxillary nerve
• third part of maxillary artery
• pterygopalatine ganglion

• Auditory ossicles
• stapedius and tensor tympani muscles
• chorda tympani nerve
• tympanic plexus (nerves)

• 1) roof (tegmental): separated cavity from middle cranial fossa
• 2) floor (jugular): separates tympanic cavity from IJV
• 3) Medial or Labarynthine wall: separates from inner ear, oval window (stapes), round window,  prominence where cochlea and run
• 4) Anterior (carotid) wall: separates from carotid canal. Has canals for tensor tympani and auditory tube
• 5) posterior or mastoid wall: stapedius attachment, prominance of facial nerve (chorda tympani) 
• 6) lateral wall: tympanic membrane

levator and tensor veli palatini

• 1) outer (cuticular layer): keratinized, squamous epithelium
• 2) Middle (fibrous) layer: radial and circular sets of collagen fibres radiating from the handle of the malleus
• 3) inner (mucous) layer: special, resp, epithelium of the middle ear. No cilia or goblet cells

• 3 crista ampullaris in the semicircular canals (head position, rotation)
• Organ of corti (hearing)
• Utricle and saccule (gravity and linear acc)

CN IX