HNS24 Vasculature And Lymphatic Of Head And Neck Flashcards
General rule of learning blood supply
Origin —> Structures supplied —> Branches —> Branch details —> Clinical examples
- External carotid
- Internal carotid
- Subclavian branches
- Veins
- Lymphatics
Aortic arch supply to head and neck
Left:
- Left subclavian
- Left common carotid —> external + internal
Right:
- Brachiocephalic (Innominate)
—> Right subclavian + Right common carotid —> external + internal
Variants:
- Left carotid and Brachiocephalic have common origin (1%-22%)
- Left carotid originates from Brachiocephalic (9%)
Carotid arteries landmarks
Bifurcation of carotid
- Upper margin of thyroid cartilage
- C4 level
(4 parts of Internal carotid artery)
(1. Cervical
2. Petrous
3. Cavernous
4. Cerebral)
External carotid artery
Supply:
- Scalp
- Face
- Maxilla
- Tongue
- Glands
- Pharynx
Branches (總共8 branches): Anterior 1. Facial 2. Maxillary (分3段, 總共13 branches) - 1st (Mandibular) - 2nd (Pterygoid / muscular) - 3rd (Pterygopalatine) 3. Superior thyroid 4. Lingual 5. Ascending pharyngeal
Middle:
1. Superficial temporal (頭頂scalp)
Posterior:
- Posterior auricular (scalp)
- Occipital (scalp)
Maxillary artery branches (X rmb detail branches)
分3段
- Mandibular (最先段) —> posterior to Lateral pterygoid muscle
- deep auricular
- anterior tympanic
- ***middle meningeal
- accessory meningeal
- inferior alveolar - Pterygoid / Muscular —> within Lateral pterygoid muscle (supply muscles)
- anterior deep temporal branches
- posterior deep temporal branches
- pterygoid branches
- masseteric artery
- buccinator artery - Pterygopalatine (最後段) —> anterior to Lateral pterygoid muscle
- posterior superior alveolar artery
- infraorbital artery
- artery of pterygoid canal
- greater (descending) palatine / pharyngeal artery
- ***sphenopalatine artery
Internal carotid artery
Supply:
- Brain
- Eye
- Nasal cavity
- Scalp
Branches: 1. Anterior and Middle cerebral artery —> Circle of Willis 2. Ophthalmic arteries —> Ocular group —> Orbital group
Circle of Willis contents
Internal carotid arteries x2 Anterior cerebral arteries x2 Posterior cerebral arteries x2 Anterior communicating artery ***x1 Posterior communicating artery x2
Ophthalmic artery (X rmb detail branches)
Runs alongside CN2 via Optic canal
—> Ocular group
—> Orbital group
- Ocular branches (eyeballs):
- Central artery of retina (end artery)
- Short / Long posterior ciliary arteries
- Anterior ciliary artery
- Superior / Inferior muscular arteries - Orbital branches:
- **Anterior / Posterior ethmoidal artery
- Dorsal nasal artery
- Supratrochlear artery
- Supraorbital artery
- **Zygomatico-facial artery
- ***Zygomatico-temporal artery
- Muscular artery
Subclavian branches
- Vertebral arteries (transverse foramina)
- Basilar artery - Internal thoracic artery
- Thyrocervical trunk
- Inferior thyroid artery (Superior: branch of external carotid)
- Ascending cervical artery - Costocervical trunk
- Deep cervical artery
Vertebral artery
- Ascend through transverse foramina of upper 6 cervical vertebrae
- Enters cranium through foramen magnum
- 2 Vertebral arteries —> Basilar artery —> 2 Posterior Cerebral arteries
—> contribute to Circle of Willis
Anastomoses regions
- Face
- Scalp
- Nasal cavity
- Thyroids + parathyroid glands
- Oral cavity
- Palate
Face anastomoses (Superior to Inferior) (External + Internal)
External carotid
- Facial artery
- Maxillary artery
- Superficial temporal artery
Internal carotid
4. Ophthalmic artery
Scalp anastomoses (Anterior to Posterior) (External + Internal)
Occurs between L/R branches, different branches of same / different origin
External carotid (Posterior)
- Superficial temporal
- Occipital
- Posterior auricular
Internal carotid (Anterior) 4. Upper branches of Ophthalmic artery —> Supratrochlear —> Supraorbital —> Zygomatico-temporal branches
Nasal cavity anastomoses (External + Internal)
External carotid
1. Facial
—> Superior labial
—> Lateral nasal
- Maxillary
—> Sphenopalatine
—> Greater palatine
Internal carotid
3. Ophthalmic artery
—> Ethmoidal branches
Clinical significance
- Kiesselbach’s area (Little’s area) —> common for nosebleeds
Thyroid and Parathyroid blood supply (External + Subclavian)
- Superior thyroid artery (from External carotid)
—> supply Superior thyroid - Inferior thyroid artery (from Subclavian via Thyrocervical trunk)
—> supply Inferior thyroid + Parathyroid - Thyroid ima artery (1-2% of population)
—> supplies Inferior thyroid
—> Clinical significance: cut vessel during neck surgery (thyroidectomy) —> uncontrollable bleeding
Oral cavity blood supply anastomoses (External ONLY)
***External carotid ONLY!!!
- Facial
—> superior labial
—> lateral nasal - Maxillary artery
—> superior / inferior alveolar buccal - Lingual artery
—> dorsal lingual
—> deep lingual
—> sublingual
Palate blood supply
***Maxillary artery ONLY (between branches of sub-branch) —> rich blood supply
- Sphenopalatine
(- after passing through nasal cavity enters palate through Incisive foramen) - Greater palatine
(- merges onto palate through Greater palatine foramen, passing forward to join Sphenopalatine artery) - Lesser palatine
(- passes through Lesser palatine foramen and supply soft palate)
Carotid Bruit
Carotid stenosis
Clinical significance: Stroke risk
3 ways:
- Narrow artery
—> ↓ blood flow - Thrombosis
- roughen arterial wall
—> blood clots
—> ↓ blood flow - Embolism
- plaque deposits / blood clots break away
—> travel to brain
—> ↓ blood flow within brain
Diagnosis
- Doppler ultrasound
- Digital angiography
Central artery of retina occlusion
ICA —> Ophthalmic arteries —> Ocular branch
- Central artery of retina
- pierces the Optic nerve —> run inside optic nerve
- emerges at centre of optic disc
- End-artery (ONLY blood supply to retina)
- emboli from Carotid can travel to it - Ciliary artery
- supply Conjunctiva, Sclera, Choroid
Venous drainage: Overview
Brain and meninges:
- Cerebral veins
- Dural venous sinuses
Head and face:
1. Veins follow arteries and have same names (e.g. facial artery and vein)
Neck:
- Anterior jugular veins
- External jugular veins
- Internal jugular veins
- Vertebral veins
Veins of face
- Facial vein:
- Union of Supratrochlear + Supraorbital vein
—> Angular vein
—> Facial vein
—> communicates with Ophthalmic, Infraorbital, Deep facial veins
—> directly into Internal jugular vein
OR
—> via Common Facial vein first (variable) —> Internal jugular vein - Retromandibular vein:
- Union of Superficial temporal + Maxillary vein
- divided into:
—> Anterior division: joins Facial vein —> Common facial vein
—> Posterior division: joins Posterior auricular vein —> External jugular vein
Anterior jugular vein
Anterior neck drainage
Starting point:
Union of Mental veins (under chin)
—> communications between 2 Anterior jugular veins at Jugular Venous Arch
—> **External jugular vein / **Subclavian vein directly
External jugular vein
Structures outside skull + External face drainage
Lies ***superficial to Sternocleidomastoid (SCM)
Starting point:
**Parotid gland (under mandible)
—> **Subclavian vein
Internal jugular vein
Starting point:
**Jugular foramen (at base of skull, as continuation of Sigmoid sinus)
—> **Subclavian vein
—> ***Brachiocephalic vein
Travels down neck in Carotid sheath with Internal / Common carotid arteries + Vagus nerve
Vertebral vein
Starting point: Small veins (at base of skull) —> Brachiocephalic vein
Travels down transverse foramina (alongside Vertebral arteries) starting at C1
—> although NOT pass through foramen magnum
Dural venous sinuses
- Formed between 2 layers of dura mater
- receive blood from brain
- Drain into ***Internal jugular vein
- Superior / Inferior sagittal
- Straight
—> Confluence of sinuses
—> Transverse
—> Sigmoid - Superior / Inferior petrosal
- Basilar
- Sphenoparietal
***6. Cavernous
***Cavernous sinus
- Large paired sinus
- in Middle cranial fossa (side of body of Sphenoid bone)
Receives blood from:
- Cerebral veins
- Ophthalmic veins (from orbit)
- Emissary veins (from pterygoid plexus)
Clinical significance:
1. Connections provide infectious pathway:
Extracranial sites (eyes, face) —> Intracranial locations
- Structures in sinus are vulnerable to injury (aneurysms of internal carotid, pituitary adenoma, cavernous sinus thrombosis):
Within sinus:
- Internal carotid artery
- CN6
On the lateral wall:
- CN3
- CN4
- CN5: V1, V2
Vertebral venous plexus
Internal + External vertebral venous plexus
- Vertebral column drainage
- receives blood from Thoracic, Abdominal, Pelvic organs
Internal vertebral venous plexus
- Connect with intracranial Dural venous sinuses (e.g. Occipital, Basilar sinuses)
Clinical significance: ***Intracranial pathway for metastasis Bloods in these valve-less veins —> allow retrograde spread of cancer cells from Thoracic, Abdominal, Pelvic regions —> Vertebral column, Spinal cord, Brain
Intracranial venous connections
Clinical significance: Facial vein (no valves) connects with: 1. Ophthalmic veins 2. Infraorbital vein 3. Deep facial vein —> pass into deeper regions of head
Interconnections with intracranial Cavernous sinus directly / via Emissary veins
Valve-less Facial vein
—> infections of face
—> extend to intracranial venous sinuses
—> ***Cavernous sinus thrombosis
Pterygoid venous plexus
Infratemporal fossa (between pterygoid muscle)
Drainage:
Nasal cavity, Paranasal sinuses, nasopharynx, oral cavity, teeth, muscles of mastication
Receives Inferior ophthalmic vein (via Inferior orbital fissure)
Important connections:
Anteriorly: Facial vein (by deep facial vein)
Posteriorly: Retromandibular vein (via maxillary vein)
Superiorly: Cavernous sinus (by emissary veins)
Diploic and Emissary veins
Diploic veins
- large thin-walled, valveless veins
- lying in Diploe (middle spongy layer of cranial bone)
- connected to Emissary veins
Emissary veins (由skull出面—>skull入面)
- small valveless veins
- pass through foramen in cranial bones
- connect to Dural venous sinuses + Meningeal veins —> Veins external of skull
Clinical significance:
- Both valve-less veins
- Possible route for spread of infection from outside to inside (e.g. osteomyelitis, meningitis, encephalitis)
- Function as alternative pathways for venous OUTflow from intracranial structures
Venous channels in Orbit
- Superior ophthalmic veins
- superior part of orbit
- leaves orbit via Superior orbital fissure —> Cavernous sinus
(- Supratrochlear + Supraorbital + Angular veins) - Inferior ophthalmic veins
- smaller
- inferior part of orbit (orbit floor)
- leaves orbit by:
—> joining Superior ophthalmic vein —> Cavernous sinus
OR
—> passing though inferior orbital fissure —> Pterygoid venous plexus
Lymphatic drainage pattern of head and neck
Superficial LN (5 groups around base of head) —>
1. Superficial cervical nodes (along **External jugular vein (SCM))
—> Deep cervical nodes (along **Internal jugular vein)
OR
2. Deep cervical nodes directly
Clinical significance:
- Obstruction —> Lymphoedema
- Channel for spread of malignant disease + infection of head and neck
- Site of primary tumour
Superficial LN (X rmb details)
5 groups of Superficial LN
—> form a ***ring at junction of head and neck
—> drain lymph from scalp + face + neck
- Occipital
- Mastoid (Posterior auricular nodes)
- Pre-auricular + Parotid
- Submandibular
- Submental
Superficial and Deep cervical LN
Superficial cervical LN:
- along ***External jugular vein
- Posterior + Posterolateral scalp drainage
Deep cervical LN:
- along ***Internal jugular vein
- ALL lymph from head and neck
- 2 groups:
1. Superior group (with Jugulo-digastric node / tonsilar)
2. Inferior group (with Jugulo-omohyoid node / lingual)
