Subclavian Artery




- Divided into 3 parts by scalenus anterior muscle
1st Part | VIT C D |
ã…¤ | Vertebral artery |
ã…¤ | Internal thoracic artery |
ㅤ | Thyrocervical trunk ↳ Suprascapular artery ↳ Inferior thyroid artery ↳ Transverse cervical artery |
2nd Part | ã…¤ |
ã…¤ | Costocervical trunk |
3rd Part | ã…¤ |
ã…¤ | Dorsal scapular artery |
Inferior Thyroid Artery supplies
- Thyroid
- Parathyroid
- Cervical part of oesophagus
- Thymus
External Carotid Artery (ECA)
- Branch of common carotid artery
- Bifurcation at C3/C4 level
- More common at C4
- At upper border of lamina of thyroid cartilage
- Mnemonic: EC 4 (C4) TC
Branches of ECA


- Medial branch
- Ascending pharyngeal artery
- Only medial branch
- First branch of ECA (VVIMP)
- Anterior branches
- Superior thyroid artery
- Lingual artery
- Facial artery
- Posterior (dorsal) branches
- Occipital artery
- Posterior auricular artery
- Only ECA branches given off in digastric triangle
- Terminal branches
- Maxillary artery → largest branch (16 branches)
- Superficial temporal artery
Arteries in Carotid Triangle
- CCA
- ECA
- ICA
- Ascending pharyngeal artery
- First ECA branch
Vertebra & Vertebral Artery
- Cervical vertebrae:
- Small body, large triangular foramen.
- Foramen transversarium – vertebral artery (except C7).
- NOTE: C7 foramen transversarium:
- transmits only vertebral vein (and sympathetic fibers)
- Thoracic vertebrae:
- Heart-shaped body, circular foramen.
- Lumbar vertebrae:
- Large kidney-shaped body.
Vertebral Artery


- Origin: 1st part of subclavian artery.
- Course: 4 parts
- Pre-foraminal (V1)
- Foraminal (V2)
- Atlanto-axial / Suboccipital (V3)
- Exits C1 foramen transversarium.
- Winds around posterior arch of atlas (C1) in suboccipital triangle.
- forms sulcus arteriae vertebralis.
- Pierces atlanto-occipital membrane and dura mater.
- Intracranial (V4)
- Enters cranial cavity via foramen magnum.
- Both sides unite at lower pons → form basilar artery.
Facial Artery
- Branch of ECA
- Origin: just above greater cornu of hyoid bone
Parts
- Cervical part
- Facial part


Branches
- Ascending palatine artery
- Tonsillar artery
- Glandular artery
- Submental artery
- Inferior labial artery
- Superior labial artery
- Lateral nasal artery
- Angular artery
- Septal branch
Maxillary artery
Branches
- gives off 16 branches
- 1st part → 5 branches
- 2nd → 5 branches
- 3rd → 6 branches


1st PART:

A-ADMI/ MET (MET = 2 meninges, 2 ear, 1 teeth)
Branches | Supplies |
Accessory Meningeal artery | Meninges |
Anterior Tympanic artery | Middle ear & inner layer of the TM |
Deep Auricular artery | inner aspect of EAC & outer layer of TM |
Middle Meningeal artery (MMA) | Major artery → enter cranial cavity |
Inferior Alveolar artery
- Runs with the inferior alveolar nerve to supply the lower teeth.
- Gives off:
- Mental Artery: Exits through the mental foramen to supply the chin.
- Mylohyoid branch: Supplies the mylohyoid muscle.
- Mnemonic: Use lower teeth () when Myran (Mylohyoid A) becomes mental (Mental A)
2nd Part → Muscular Branch → Muscles of Mastication
- 'A' to Med. Pterygoid
- 'A' to Lat. Pterygoid
- Masseteric Art.
- Deep temporal Art. [to Temporalis]
- Buccal Art → Buccinator [Accessory ms of mastication]
3rd Part
Mnemonic: "PIG PAS"
- P – Posterior Superior Alveolar Artery
- I – Infraorbital Artery
- G – Greater Palatine Artery
- P – Pharyngeal Artery
- A – Artery to Pterygoid Canal (Vidian Artery)
- S – Sphenopalatine Artery
- Largest branch of maxillary artery
- Main artery involved in posterior epistaxis

Venous drainage of face

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- Venous drainage of Face:
- Via deep facial vein → pterygoid venous plexus
- Via angular vein → superior ophthalmic vein
- Superior ophthalmic vein is valveless


Nerve Supply to face
- Motor supply: Facial nerve.
- Sensory supply: Trigeminal nerve.

Branches of Trigeminal Nerve and Areas Supplied
Branch of Trigeminal Nerve | Area Supplied |
Ophthalmic Nerve | - Forehead - Upper eyelid - Root/tip of nose - Cheek |
Maxillary Nerve | - Side of nose - Lower eyelid - Upper lip |
Mandibular Nerve | - Adjoining area of auricle & temple - Lower lip - Chin |
Note
- Great auricular nerve supplies
- skin over angle of mandible/shaving area/beard area.
Lymph Nodes in the Neck

7 Groups
- I: Submental, submandibular.
- II: Upper jugular nodes
- III: Mid jugular nodes
- IV: Lower jugular nodes
- V: Occipital nodes in posterior triangle of neck
- VI: Anterior nodes (hyoid to sternum)
- VII: Mediastinal nodes.
Jugular nodes
- Lies close to IJV.
- Deep to SCM
Applied Aspect
In Carcinoma of Oral Cavity
Radical Neck Dissection | Modified Radical Neck Dissection |
Carcinoma | Carcinoma |
Level I–V nodes | Level I–V nodes |
SCM | ã…¤ |
IJV | ã…¤ |
Spinal part of accessory nerve | ã…¤ |

- Incision: Mod. Schrodinger incision
Type | Description |
Radical ND (Crile) | Removes = 1-5 LNs + SCM, IJV, SAN + Submandibular gland, parotid tail |
Modified Radical ND | Removes = 1-5 LNs + Saves ≥ 1 structure (SAN/ IJV/ SCM) Types: • I (SAN saved) • II (SAN + IJV saved) • III (all saved) → Functional Neck Dissection Rest all same as Crile |
Selective ND | Central: • Level 6 (Delphian LN); Supraomohyoid: • Levels I-III → (SOHND) Extended: • Levels I-IV → (Extended SOHND) |
Type of MRND | Structures Preserved |
MRND I | Spinal Accessory Nerve (SAN) |
MRND II | SAN + Internal Jugular Vein (IJV) |
MRND III | SAN + IJV + Sternocleidomastoid (SCM) |

- NOTE: T1/T2 lesions →
- Sentinel lymph node biopsy (SLNB)
- Prophylactic ND (SOHND)
- Both offer Better prognosis.
- Complications:
- Haemorrhage
- Carotid blowout (high mortality)
- Nerve injuries:
- Ramus mandibularis/ Marginal mandibular (drooping of angle of mouth)
- SAN (shoulder dysfunction),
- hypoglossal, ansa cervicalis
- Modified Schoebinger incision
- 2 finger breadth below angle of mandible
- To prevent marginal mandibular N injury
