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This section deals with the major autonomic and neural structures of the head and neck. It includes the parasympathetic ganglia, important arteries, pharyngeal arch derivatives, and clinically relevant anatomical terms. Understanding these nerves and ganglia is essential for correlating cranial nerve functions with glands, smooth muscles, and mucosal secretions.
• Formed by the anterior rami of C1–C4.
• Lies deep to the sternocleidomastoid on the levator scapulae and scalenus medius.
• Divided into cutaneous and muscular branches.
• Lesser occipital nerve
• Great auricular nerve
• Transverse cervical nerve
• Supraclavicular nerves
These emerge from the midpoint of the posterior border of sternocleidomastoid.
• Supply prevertebral muscles, levator scapulae, trapezius (with accessory nerve).
• Contributes fibres to the ansa cervicalis for infrahyoid muscles.
• Arises from C3, C4, C5 (“C3,4,5 keep the diaphragm alive”).
• Descends on the anterior scalene muscle.
• Enters thorax between subclavian artery and vein.
• Motor nerve of the diaphragm.
• Sensory to:
– Mediastinal pleura
– Central diaphragmatic pleura
– Central diaphragm peritoneum
• Irritation of phrenic nerve → referred pain to shoulder (C4 dermatome).
• Phrenic nerve palsy → elevated hemidiaphragm on X-ray.
• Lies behind the carotid sheath, anterior to prevertebral fascia.
• Contains no white rami communicantes (these appear only T1–L2).
• Consists of three ganglia:
• Largest; located at C2–C3 level.
• Sends fibres to head and neck: pupil dilation, sweating, vasoconstriction.
• Small; at C6 level, near cricoid cartilage.
• Often fuses with first thoracic ganglion → stellate ganglion.
• Interruption produces Horner syndrome (ptosis, miosis, anhidrosis).
Four paired parasympathetic ganglia supply structures of the head:
• Ciliary ganglion
• Pterygopalatine ganglion
• Submandibular ganglion
• Otic ganglion
All receive:
• Parasympathetic root (secretomotor)
• Sympathetic root
• Sensory root
• Only parasympathetic fibres synapse inside the ganglion.
• Small, fusiform ganglion suspended from the lingual nerve.
• Located on the medial surface of the submandibular gland.
• Parasympathetic root:
– From chorda tympani → joins lingual nerve → reaches the ganglion → synapses.
• Sympathetic root:
– From facial artery plexus; fibres pass through without synapse.
• Sensory root:
– From lingual nerve.
• Postganglionic parasympathetic fibres supply:
– Submandibular gland (secretomotor)
– Sublingual gland
– Small mucous glands in floor of mouth
• Lesions → dryness of mouth, reduced submandibular–sublingual secretion.
• Important in surgeries involving floor of mouth, submandibular duct, and lingual nerve.
• Largest parasympathetic ganglion in the head.
• Lies in the pterygopalatine fossa, just below the maxillary nerve.
• Parasympathetic root:
– Preganglionic fibres via greater petrosal nerve.
– Joins deep petrosal nerve → nerve of pterygoid canal → ganglion → synapse.
• Sympathetic root:
– From deep petrosal nerve (plexus around internal carotid).
– Pass through without synapse.
• Sensory root:
– From maxillary nerve (V2).
• Lacrimal gland (via lacrimal nerve pathway).
• Nasal mucous glands.
• Palatine mucous glands.
• Nasopharyngeal glands.
• Ganglion block used in migraine and cluster headache.
• Lesions → dryness of nasal and palatal mucosa, reduced tear secretion.
• Small parasympathetic ganglion located below the foramen ovale, medial to mandibular nerve.
• Functionally associated with glossopharyngeal nerve (IX).
• Parasympathetic root:
– Preganglionic fibres via lesser petrosal nerve → synapse in ganglion.
• Sympathetic root:
– From plexus around middle meningeal artery; pass through.
• Sensory root:
– From mandibular nerve (V3).
• Secretomotor supply to parotid gland, via auriculotemporal nerve.
• Lesions lead to reduced parotid secretion.
• Site of Frey syndrome (gustatory sweating) when auriculotemporal nerve regenerates aberrantly.
• Small parasympathetic ganglion located in the orbit, between optic nerve and lateral rectus.
• Parasympathetic root:
– From oculomotor nerve (branch to inferior oblique).
– Synapse inside ganglion.
• Sympathetic root:
– From internal carotid sympathetic plexus; pass through.
• Sensory root:
– From nasociliary nerve.
• Postganglionic fibres emerge as short ciliary nerves supplying:
– Sphincter pupillae (pupil constriction)
– Ciliaris muscle (accommodation)
• Lesions cause:
– Dilated pupil (loss of sphincter pupillae)
– Loss of accommodation
– Light-near dissociation in selective damage
• Divides at the level of upper border of thyroid cartilage.
• Right side arises from brachiocephalic trunk; left from arch of aorta.
Mnemonic: “Some Anatomists Like Freaking Out Poor Medical Students”
• Superior thyroid
• Ascending pharyngeal
• Lingual
• Facial
• Occipital
• Posterior auricular
• Maxillary
• Superficial temporal
• No branches in neck.
• Enters carotid canal → supplies brain, eye, forehead.
• Vertebral artery
• Internal thoracic
• Thyrocervical trunk
• Costocervical trunk
• Dorsal scapular artery (variable)
• Passes through transverse foramina (C6 to C1).
• Enters cranial cavity through foramen magnum.
• Carotid pulse felt at anterior border of SCM.
• Carotid sinus hypersensitivity → syncope.
• Vertebral artery compromise → dizziness, ataxia.
The pharyngeal apparatus consists of arches, pouches, grooves (clefts), and membranes.
Each arch contains a cartilage, artery, muscle, and cranial nerve.
• Nerve: Trigeminal (V3)
• Muscles: Muscles of mastication, mylohyoid, anterior digastric, tensor tympani, tensor palati
• Skeletal: Malleus, incus, mandible template
• Artery: Maxillary artery
• Nerve: Facial (VII)
• Muscles: Facial expression, stapedius, stylohyoid, posterior digastric
• Skeletal: Stapes, styloid process, lesser horn of hyoid
• Artery: Stapedial artery (embryonic)
• Nerve: Glossopharyngeal (IX)
• Muscles: Stylopharyngeus
• Skeletal: Greater horn of hyoid
• Artery: Common carotid, proximal internal carotid
• Nerve: Superior laryngeal branch of vagus (X)
• Muscles: Pharyngeal constrictors, cricothyroid, levator palati
• Skeletal: Laryngeal cartilages (upper)
• Artery: Aortic arch (left), subclavian (right)
• Nerve: Recurrent laryngeal nerve (X)
• Muscles: Intrinsic laryngeal muscles (except cricothyroid)
• Skeletal: Laryngeal cartilages (lower)
• Artery: Pulmonary arteries, ductus arteriosus
• 1st pouch: Auditory tube + middle ear cavity
• 2nd pouch: Palatine tonsil epithelium
• 3rd pouch: Inferior parathyroids + thymus
• 4th pouch: Superior parathyroids + ultimobranchial body (→ C cells of thyroid)
• 1st groove: External auditory meatus
• Others disappear → if persistent → branchial cysts/sinuses
• 1st membrane: Tympanic membrane
• Others disappear
Each pharyngeal arch contains a cartilage, muscle group, nerve, and artery. Their derivatives are:
• Maxilla
• Mandible (template)
• Zygomatic bone
• Part of temporal bone
• Malleus & Incus
• Muscles of mastication
• Mylohyoid
• Anterior belly of digastric
• Tensor tympani
• Tensor palati
• Mandibular division of trigeminal nerve (V3)
• Maxillary artery
• Stapes
• Styloid process
• Stylohyoid ligament
• Lesser horn & upper body of hyoid
• Facial expression muscles
• Stapedius
• Stylohyoid
• Posterior belly of digastric
• Facial nerve (VII)
• Stapedial artery (embryonic)
• Greater horn of hyoid
• Lower body of hyoid
• Stylopharyngeus
• Glossopharyngeal nerve (IX)
• Common carotid
• Proximal internal carotid
• Laryngeal cartilages (upper part)
• Cricothyroid
• Levator palati
• Pharyngeal constrictors
• Superior laryngeal branch of vagus (X)
• Aortic arch (left)
• Right subclavian artery (right)
• Laryngeal cartilages (lower part)
• Intrinsic muscles of larynx (except cricothyroid)
• Recurrent laryngeal branch of vagus (X)
• Pulmonary arteries
• Ductus arteriosus
• Middle ear cavity
• Mastoid air cells
• Auditory (Eustachian) tube
• Epithelial lining of palatine tonsils
• Dorsal wing → Inferior parathyroid glands
• Ventral wing → Thymus
(Mnemonic: The 3rd pouch migrates further, so its parathyroids become “inferior.”)
• Dorsal wing → Superior parathyroid glands
• Ventral wing → Ultimobranchial body → C cells of thyroid
• External auditory meatus
• Outer surface of tympanic membrane
• Normally obliterated by overgrowth of the 2nd arch
• Persistence → branchial cysts, sinuses, or fistulae along anterior border of sternocleidomastoid
• Branchial cyst – Persistent cervical sinus; found along anterior border of sternocleidomastoid.
• Branchial fistula – Persistence of a second cleft connection to pharynx.
• DiGeorge syndrome – Failure of 3rd and 4th pouches → absent thymus & parathyroids → hypocalcemia & immune deficiency.
• Treacher Collins syndrome – First arch neural crest defect → mandibular hypoplasia, ear anomalies.
• Pierre Robin sequence – 1st arch defect → micrognathia, glossoptosis, cleft palate.
• Thyroglossal cyst – Persistence of thyroglossal duct, midline swelling.
• Laryngomalacia – Soft laryngeal cartilages (arch 4 & 6 involvement).
• Choanal atresia – Failure of oronasal membrane to rupture; neonates present with cyanosis relieved by crying.
The development of pharyngeal arches depends on coordinated signalling between neural crest, mesoderm, endoderm, and ectoderm.
• Hox genes
– Establish cranio-caudal patterning of arches (absent in 1st arch).
• FGF (Fibroblast Growth Factors)
– Essential for formation and survival of arch mesenchyme.
• BMP (Bone Morphogenetic Proteins)
– Patterning of skeletal elements; high BMP drives cartilage differentiation.
• SHH (Sonic Hedgehog)
– Governs outgrowth of facial processes; regulates neural crest migration.
• Endothelin-1
– Key regulator for mandibular arch (1st arch) patterning.
• PAX genes
– Important for segmentation and cranial neural crest differentiation.
• Retinoic acid
– Too little or too much disrupts pharyngeal apparatus (causes arch defects).
(from the section labeled HEAD AND NECK SPOTS)
a. Identify the foramen.
→ Foramen magnum
b. Structures passing through it:
Lowest part of medulla oblongata
Three meninges
One anterior spinal artery
Two posterior spinal arteries
Two vertebral arteries
Spinal root of accessory nerve
a. Identify the foramen.
→ Mandibular canal
b. Structures passing through it:
Inferior alveolar artery
Inferior alveolar nerve
a. Identify the muscle.
→ Orbicularis oculi
b. Parts:
Orbital part
Palpebral part
Lacrimal part
a. Identify the circled structure.
→ Chorda tympani nerve
b. Types of fibres carried:
General visceral efferent (GVE)
Special visceral afferent (taste)
a. Identify the highlighted structure.
→ Parotid gland
b. Secretomotor pathway:
Inferior salivatory nucleus → Glossopharyngeal nerve (IX) → Tympanic plexus → Lesser petrosal nerve → Otic ganglion → Auriculotemporal nerve → Parotid gland
a. Identify the structure.
→ External carotid artery
b. Branches (in order):
Anterior: Superior thyroid, Lingual, Facial
Medial: Ascending pharyngeal
Posterior: Occipital, Posterior auricular
Terminal: Maxillary, Superficial temporal
a. Identify the marked area.
→ Little’s area (Kiesselbach’s plexus region)
b. Vessels present:
Superior labial
Greater palatine
Anterior ethmoidal
Sphenopalatine
(Capillaries + venous plexus)
a. Identify the structure.
→ Tongue
b. Extrinsic muscles with nerve supply:
Palatoglossus → Vagus (via pharyngeal plexus)
Hyoglossus → Hypoglossal nerve
Styloglossus → Hypoglossal nerve
Genioglossus → Hypoglossal nerve
a. Identify the muscle.
→ Posterior cricoarytenoid
b. Action:
Only abductor of the vocal cords
a. Identify the organ.
→ Palatine tonsil
b. Arterial supply:
Ascending palatine artery
Ascending pharyngeal artery
Dorsal lingual arteries
Greater palatine artery
These answers are exactly the same as above—page 360 is the printed “Answers” page that corresponds to the same items.
Everything from 1 to 10 already retrieved and presented above matches the answers section.
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