L9: Blood vessels of the head and neck

Question 1

What veins drain the front of the scalp?

Answer 1

Supra-orbital vein
Supratrochlear vein
These drain down the face into the facial vein

Question 2

What two veins form the retromandibular vein?

Answer 2

Superficial temporal vein (drains side of scalp) and occipital vein (drains back of scalp)

Question 3

What forms the external jugular vein?

Answer 3

Posterior auricular vein joins the retromandibular vein, forming the external jugular vein which then drains into the subclavian vein

Question 4

How is the scalp drained?

Answer 4

Most of the scalp drains superficially but some doesn’t
Scalp has a connection to the internal cavity of the skull
-emissary veins drain through the skull into areas called dural venous sinuses
-collection of venous blood between the periosteal and meningeal dura
RISK OF INFECTION= CAUSE MENINGITIS

Question 5

How is the face drained?

Answer 5

Supra-orbital and supratrochlear join to form the angular vein which then forms the facial vein and this comes together with other veins to form the common facial vein which drains into the internal jugular vein.
(this is superifical)
-there is also deep drainage of the face, some vessels move back deeper into the head and join at the cavernous sinus

Question 6

What veins drain into the cavernous sinus?

Answer 6

• superior and inferior opthalmic veins drain backwards
• some deep facial veins which drain backwards to the pterygoid venous plexus which is connected to the cavernous sinus by veins (these veins can be route of infection into the skull)

Question 7

What is the danger triangle of the face?

Answer 7

The region where the facial vein can drain backwards into the cavernous sinus
Infections can spread via facial vein and ultimately end up in the dural venous sinuses

Question 8

Give some names of dural venous sinuses:

Answer 8

• superior sagittal sinus (along centre of head)

- inferior sagittal sinus

Question 9

How do the dural venous sinuses work?

Answer 9

• cerebral veins drain cerebral structures
• blood leaves these veins and enters the superior/ inferior sagittal sinus
• blood flows backwards and down the head, the superior and inferior sagittal sinus meet at the confluence of the sinuses
• this forms the transverse sinus (left and right) which moves in an S shaped pattern either side and leave through a hole called the jugular foramen

Question 10

What does the transverse sinus change its name to once it has passed through the jugular foramen?

Answer 10

Internal jugular vein

Question 11

Why do we use the right internal jugular vein to asses jugular venous pressure?

Answer 11

As it is directly connected to the right atrium

Question 12

How do you take the JVP?

Answer 12

• patient at 45 degree elevation
• head turned to left
• IJV is mostly hidden by the SCM
• look for pulsations behind the SCM
• measure to where the pulsations stop from the sternal angle, then +5cm to work out distance from heart