Venous Drainage of Head and Neck Flashcards
Where to the veins draining the head and neck lie?
Either superficial or deep to the investing layer of deep cervical fascia in the neck
Are there distinct fascial layers in the face?
No, muscle attaches between bone and skin
Where does the facial vein run?
With the facial artery, from the medial angle of the eye towards the inferior border of the mandible
What does the facial vein drain?
Most structures of the face
What does the facial vein drain into?
The internal jugular vein
Where does the internal jugular vein lie?
Lateral to the common carotid, mostly under the sternocleidomastoid
What does the facial vein have a numbr of important anastomoses with?
Veins draining deeper structures within the skull
Where does the facial vein recieve blood from?
The superior and inferior opthalmic veins
Where does the facial vein communicate with the superior opthalmic?
At the medial angle of the eye
What do the superior and inferior opthalmic veins have a direct connection with?
The pterygoid venous plexus and cavernous sinus
Where does the cavernous sinus lie?
Intra-cranially
What is the cavernous sinus part of?
The intra-cranial venous system
What is the cavernous sinus?
A plexus of extremely thin walled veins on the upper surface of the sphenoid
What structures other than veins are found in the cavernous sinus?
- Internal carotid artery
- CN III oculomotor
- CN IV trochlear
- CN VI abducent
- 2 branches of trigeminal; CN V1 opthalmic and CN V2 maxillary
Where does cavernous sinus sit?
On the sphenoid bone, either side of pituitary
What is the result of the connection between the superior and inferior opthalmic veins (and therefore the facial veins) and the cavernous sinus?
It has implications for infections involving the face, acting as a potential route for infection to track deeper into intra-cranial structures
What can formation of a septic thrombi, secondary to infection, in the facial vein cause?
The septic thrombi can pass into the cavernous sinus, leading to a cavernous sinus thrombosis
Where is infection most likely to cause the formation of a septic thrombi in the facial vein?
Near the angle of the eye
Where do deep facial veins drain into?
The pterygoid venous plexus
Do veins of the face have valves?
No
What is the result of the veins of the face being valveless?
Blood can flow in either direction
What is the result of blood in the veins of the face being able to flow in either direction?
- Infection from facial vein can spread to dural venous sinuses
- Infected clots can travel to intracranial venous system
What is thrombophlebitis of the facial vein?
Where there is an inflammation or infection of the vein, and a clot forms
What is the result of an infected clot travelling to the intracranial venous system?
Carries infection deeper
What is the clinical relevance of the danger triangle of the face?
Infections in this region of the face can spread through the venous system to dural venous sinuses, e.g. if a spot gets infected in this area
Insert venous draining of face and head diagram
What do the superficial veins accompany?
Arteries
What superficial veins accompanying an artery drain the scalp?
- Superficial temporal veins
- Occipital veins
- Posterior auricular
Where do the supraorbital and supratrochlear veins unite?
At the medial angle of the eye
What is formed when the supraorbital and supratrochlear veins unite?
The angular vein
What does the angular vein drain into?
The facial vein
What do the veins of some parts of the scalp in the temporal region drain into?
The pterygoid venous plexus
What are dural venous sinuses?
Endothelium lined-spaces between periosteal and meningeal layers of dura
Where do dural venous sinuses form?
At dural septae
Where do dural venous sinuses recieve blood from?
Large veins draining brain
Give 4 dural venous sinuses
- Superior sagittal sinus
- Inferior sagittal sinus
- Cavernous sinus
- Transverse sinus
How does the transverse sinus continue?
As the sigmoid sinus, which continues as internal jugular veins
How do the internal jugular veins leave the skull?
Through the jugular foramina
How do the veins of the skull connect to diploic veins of the skull?
Through several emissary veins, and thus dural venous sinuses
Do emissary veins have valves?
No
What is the result of the emissary veins being valveless?
Blood can flow in either direction, so infection from scalp can spread to cranial cavity and affect the meninges
