Session 1.3b - Pre-Reading (Venous Drainage of Head and Neck A) Flashcards
https://www.youtube.com/watch?v=s3-sRxwyN3c
What is the main vein that drains the structures of the scalp, face and the neck?
The internal jugular vein (IJV)
The IJV drains the scalp, face and the neck. Which parts of the face does it drain?
- Orbit/nasal cavity
- Oral cavity
Veins that drain the scalp and the face also have venous connections with ___?
A number of intracranial venous structures - veins essentially draining the brain that lie within the skull.
Veins that drain the _____ and the ____ also have venous connections with ____________ _____ / ______.
Veins that drain the scalp and the face also have venous connections with intracranial veins/plexus.
The IJV is a continuation of one of the veins within the _____
Skull
The IJV is a continuation of one of the veins within the skull. How does this vein exit the skull to become to the IJV?
it exits through the jugular foramen.
After arising from the jugular foramen, the IJV runs down the length of the neck, enclosed within which structure?
The carotid sheath
Broadly, which veins drain the head and neck?
Lots of different veins with connections from veins on the face and the scalp, and veins that we find deeper intracranially.
The IJV runs through the carotid sheath with which artery?
The internal carotid artery and the common carotid artery
ICA above C4, CCA below (before bifurcation)
The IJV runs through the carotid sheath with the external carotid artery. True or false?
False; the CCA bifurcates into the ICA and the ECA. The ICA lies within the carotid sheath, whilst the ECA lies outside.
The IJV leaves the jugular foramen to run the length of the neck, before ultimately joining with which vein?
The subclavian vein.
The IJV joins with the subclavian vein to form which structure?
The brachiocephalic vein
The brachiocephalic vein drains into which side of the heart?
Right
IMAGE 1
Label the:
- bony skull
- cervical vertebra
- venous structures (sigmoid sinus and IJV)
Broadly labelled image of side of the head.
IMAGE 1
What are the slightly paler venous structures?
These denote the veins that lie intracranially, known as the dural venous sinuses
Where are the dural venous sinuses found?
Intracranially
What do the dural venous sinuses drain?
The brain and other structures within the skull.
Which sinus leaves the skull to become the IJV?
The sigmoid sinus
What structure and where does the sigmoid sinus leave to make the origin of the IJV?
Posteriorly exits the skull
Why is the sigmoid sinus so-named?
It is S-shaped and curved
How does the sigmoid sinus leave the skull?
Via the cranial fossa and out through the jugular foramen.
Where is the origin of IJV?
At the intersection of the jugular foramen, where the sigmoid sinus leaves the skull (it is a continuation of intracranial venous structures).
The sigmoid sinus passes through the jugular foramen to leave the skull, and the _______ _____ within the skull.
Cranial fossa
Where do all the other dural venous sinuses ultimately drain into?
These all essentially join and drain through the sigmoid sinus into the IJV.
IMAGE 2
Label the:
- Dural venous sinuses (don’t need individual)
- Sigmoid sinus
- Internal jugular vein
- Transverse sinus
- Jugular foramen
- Cavernous sinus
- Superior & inferior petrosal sinuses
See image
IMAGE 3
Describe the orientation of this skull
Here we are looking at the FLOOR of the cranial cavity.
At the top is the front (anterior aspect), whilst the bottom represents the back (posterior aspect).
The green pipe cleaners represent some of the dural venous sinuses that we find within the cranial cavity.
IMAGE 3
Label the:
- Transverse sinus
- Sigmoid sinus
- Jugular foramen
- Cavernous sinus
- Superior petrosal sinus
- Inferior petrosal sinus
Some of the dural venous sinuses that we find within the cranial cavity.
Where does the transverse sinus lie?
It runs transversely across the floor of the posterior cranial fossa
Which vein lies across the floor of the posterior cranial fossa?
The transverse sinus
How does the transverse sinus become the sigmoid sinus?
It runs around the posterior cranial fossa as the transverse sinus, and then it takes a turn and runs inferiorly towards the jugular foramen as the sigmoid sinus.
The transverse sinus runs transversely across the floor of the posterior cranial fossa. It then travels __________ towards the _______ _______ as which structure?
posteriorly; jugular foramen; as the sigmoid sinus.
The cavernous sinus has connections with other dural venous sinuses. True or false?
True
The cavernous sinus sits either side of which structure?
The sella turcica (this lies medially to the cavernous sinus)
What does the posterior aspect of the cavernous sinus connect to?
A number of dural venous sinuses (SPS and IPS) connecting with the back of the cavernous sinus with the sigmoid sinus.
Where does the cavernous sinus connect to the sigmoid sinus?
The posterior aspect of the cavernous sinus
What are the two sinuses called that arise from the posterior aspect of the cavernous sinus, connecting to the sigmoid sinus?
- Superior petrosal sinus
- Inferior petrosal sinus
Where is the inferior petrosal sinus?
It runs from the lower part of the posterior part of the cavernous sinus (and hence the superior inferior sinus runs from the upper part of the posterior part of the cavernous sinus) to the sigmoid sinus.
Where does the cavernous sinus drain into?
Essentially, whatever is draining into the cavernous sinus ultimately makes its way through other venous connections to drain out through the IJV.
Dural venous sinuses are ____________ veins.
Intracranial veins
Dural venous sinuses relate to the ______ of the internal jugular vein via the _______ _____
Dural venous sinuses relate to the origin of the IJV via the sigmoid sinus
The cavernous sinus is a type of ___?
Dural venous sinus
The cavernous sinus also has links to ___?
The origin of IJV
Key veins of the face/orbit communicate with the ___ and _________ _____?
IJV, cavernous sinus
What is the venous plexus in the face known as?
Pterygoid venous plexus
The pterygoid venous plexus has connections to?
Some of the veins in or draining the face/orbit, and the cavernous sinus.
IMAGE 4
On this basic schematic representation, which side of the head are we looking at?
Right
IMAGE 4
Draw on the:
- Mandible
- Bony orbit
- Cavernous sinus (CS)
- Base of the skull
- Pterygoid venous plexus (PP)
- Internal jugular vein
- Facial vein
- Superior opthalmic vein
- Inferior opthalmic vein
- Veins that drain the maxilla/nasal cavity (rough)
- Emissary veins
See image
Where is the location of the cavernous sinus (CS)?
Intracranial - inside cranium
Where is the pterygoid venous plexus (PP or PVP) found?
In a space known as the infratemporal fossa (extra-cranial)
Where is the infratemporal fossa?
Deep to the ramus of the mandible
Extra-cranial - not within the cranium
Both the cavernous sinus and pterygoid venous plexus are ___?
Collections/networks of veins.
The cavernous sinus and pterygoid venous plexus receive ___?
Venous blood from branches that relate to veins that draining the structures of the face, including the orbit, nasal and oral cavity.
What is the key venous structure draining the face?
Facial vein
Where is the facial vein?
Arises from the medial aspect of the orbit, descends down the face in a posterior-inferior route to drain into the IJV.
Which veins is the facial vein connected with around the orbit?
- Superior ophthalmic vein
- Inferior ophthalmic vein
The ophthalmic veins both drain where?
Into the cavernous sinus
The ophthalmic veins drain what, and thus, so does which structure?
Tissue structures within the orbit of the eye, and because of their communication with the cavernous sinus, so does the cavernous sinus.
Venous drainage from the orbit can descend down the facial vein. How?
Because the ophthalmic veins, which drain the tissues of the eye, have communications with the facial vein, some there’ll be some venous drainage from the orbit running down the facial vein and into the IJV.
Which vein drains posteriorly into the pterygoid venous plexus (PP) - the superior or inferior ophthalmic vein?
The inferior ophthalmic vein
think location
The inferior ophthalmic vein drains ___________ into the PP.
Posteriorly
The PP is quite an _________ area of veins.
Extensive
Give examples of where the PP receives blood from.
- The orbit
- Venous tributaries from areas of the face that are supplied by the maxillary artery, e.g. maxilla, nasal cavity
Give some examples of areas of the face supplied by the maxillary artery.
- Maxilla
- Nasal cavity
Areas of the face supplied by the maxillary artery are connected with where?
The facial vein and the pterygoid venous plexus.
What is the veins that connect the PP to the CS called?
Emissary veins
What are emissary veins?
A series of small veins that connect the PP to the CS.
Where do emissary veins pass?
These pass through the bone of the floor of the skull, to connect the PP to the CS (extracranial to intracranial)
How might blood that drains extracranially run intracranially?
Any blood that’s draining from an area within the face, that’s passing into the PP, could potentially run into intracranial venous structures because of the communication of the PP to the CS via emissary veins.
IMAGE 5
Which side are we looking at?
Left-hand side of the skull.
IMAGE 5
Label 9 of the venous structures
Clues:
- Facial vein
- Ophthalmic veins (relates to structures of the orbit)
The image illustrates we have a number of superficial venous structures, and a number of deep ones; including some in the skull itself.
See image (circled) + deep facial v. & superior and inferior petrosal sinuses
The ________ and ________ ophthalmic veins run ______________ to join the _________ _____ which is lying ______ the skull.
The superior and inferior ophthalmic veins run intracranially to join the cavernous sinus, which is lying within the skull.
The cavernous sinus drains posteriorly into another series of _____ ______ _______; the _______ and ________ ________.
dural venous sinuses; the superior and inferior petrosals.
How does the blood from the cavernous sinus reach the internal jugular vein?
The cavernous sinus drains posteriorly into the superior and inferior petrosals, eventually draining in the sigmoid sinus, which continues through the jugular foramen as the internal jugular vein.
The CS reaches the IJV via which part of the skull?
The jugular foramen (CS eventually drains the sigmoid sinus, which leaves here to become the IJV)
The superior and inferior petrosal sinuses drian into which structure?
Sigmoid sinus.
The PP has connections with which major vein?
Deep facial vein
The complex PP will receive venous tributaries from where?
The maxilla and nasal cavity
IMAGE 5
Also label:
- Jugular foramen
- Emissary veins
- Danger triangle
- Jugular foramen: as sigmoid sinus leaves skull to become IJV
- Emissary veins: small veins connecting the PP to the CS
- Danger triangle: apex at bridge of nose, to corners of mouth.
How can an infection in the face spread intracranially?
Superficial infections of face –> Spread via pterygoid plexus –> To cavernous sinus
Rationale:
Superficial infections of the face, particularly in the danger triangle, may potentially spread into the PP, should it involve the veins. Very rarely, this may spread even deeper still into the CS, due to the connection of the PP to the CS via the emissary veins. The CS is an intracranial venous structure, thus, infections from the face can spread intracranially.
Why are we concerned about infections that have spread to involve intracranial structures?
Due to the high risk of quite concerning complications!
What are some complications of infections that have spread to the cavernous sinus?
- Cavernous sinus thrombosis
- Meningitis
The PP ultimately drains where?
Into the internal jugular vein
Which vein essentially drains the PP?
The maxillary vein
(- Don’t need to know the veins that run between the maxillary vein and the IJV)
- Just need to know that PP will also drain into the IJV
What is a complication of where infections can travel to, due to venous drainage of the head (and neck)?
Should we have an infection within the superficial structures of the face, we could potentially get infections tracking to deeper structures, such as and via the PP or even the CS.
Equally, infections in relation to the orbit could also potentially track into intracranial venous structures (via the CS).
(i.e. via the cavernous sinus)
Summarise this deck.
- Origin of the IJV
- Connections between superficial veins draining the face/orbits (pterygoid venous plexus) and intracranial venous structures (cavernous sinus)
