Session 1.3d - Lecture (Blood Vessels of the Head and Neck) Flashcards

1
Q

Major Blood Vessels of the Head & Neck - ILO

  • Arteries and veins in the neck
  • Carotid triangle
  • Blood supply/venous drainage
  • Clinical relevance
A
  • Arteries and veins in the neck
  • Review the carotid triangle
  • Blood supply and venous drainage of the neck, face, scalp, dura and skull
  • Clinical relevance
  • —- Pulses and JVP (how that’s measured)
  • —- Routes of infection
  • —- Atheroma
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2
Q

Slide 4

Label the:

  • Left and right side
  • Sternocleidomastoid (and its two heads)
  • External jugular vein (x2)
  • Internal jugular vein
  • Common carotid artery
  • Sternohyoid muscle
A

See lecture

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3
Q

Slide 4

Identify SCM and its two heads.

A

(See slides) SCM muscle and its two heads visible on the RHS.

LHS - SCM has been removed.

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4
Q

Slide 4

Identify the sternohyoid muscle.

A

(See Notability) Thin, narrow, muscle that runs longitudinally from the hyoid bone down to the sternum. Visible on the RHS behind (deep) the SCM; partially cut away on the LHS.

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5
Q

Slide 4

Identify the:

  • thyroid gland
  • trachea
  • thyroid cartilage
A

See Notability

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6
Q

Where does the common carotid artery lie?

A

Lies deep to the SCM - cannot be viewed until SCM has been moved aside

(apart from in a section just inferior to the hyoid bone, and medial to the SCM - shown on Slide 4 RHS)

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7
Q

Where does the internal jugular vein lie?

A

Lateral to the CCA, but similarly to the CCA it is hidden by the SCM muscle.

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8
Q

Where does the IJV drain into?

A

This major vein drains into the brachiocephalic vein (also covered by the SCM).

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9
Q

Which vein in the neck is more readily visible?

A

The EJV is more readily visible because it’s coursing more superficially over the SCM.

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10
Q

Slide 5

Label the:
- left and right
- arch of aorta
- brachiocephalic trunk
- left subclavian artery
- left common carotid artery
(And any other structures [not arteries] you can label)
A

See slides

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11
Q

The brachiocephalic trunk is found on which side of the body?

A

Right

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12
Q

The brachiocephalic trunk gives rise to which two arteries?

A

The common carotid artery and the subclavian artery.

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13
Q

The right CCA and right subclavian artery arise from where?

A

Brachiocephalic trunk

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14
Q

The left CCA and left subclavian artery arise from where?

A

Directly off the arch of aorta

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15
Q

The arch of aorta gives rise to which arteries?

A

The brachiocephalic trunk (right), the left CCA and the left subclavian artery.

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16
Q

The CCA bifurcates to give what?

A

The internal and external carotid arteries

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17
Q

The internal and external carotid artery arise from where?

A

The bifurcation of the CCA (at about C4 level)

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18
Q

Where does the CCA bifurcate?

A

At the superior border of the thyroid cartilage - which is approximately C4 level.

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19
Q

Which artery(s) gives off branches in the neck - the external, internal or common carotid artery?

A

ECA

The ICA and CCA do not give off any branches in the neck.

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20
Q

The vertebral artery comes from which artery on which side?

A

The subclavian artery on both sides

the right and left vertebral artery arise from the right and left subclavian artery, respectively

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21
Q

What branches does the vertebral artery give off in the neck?

A

It doesn’t (like the ICA, heads up into the skull)

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22
Q

The thyrocervical trunk arises from which artery?

A

The subclavian artery

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23
Q

The inferior thyroid artery arises from where?

A

The thyrocervical trunk (from the subclavian artery).

It loops behind the CCA so appears that it branches off there but it doesn’t, it arises from the subclavian

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24
Q

What does the inferior thyroid artery supply?

A

The lower lobe of the thyroid gland.

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25
Q

What is the arterial supply to the lower lobe of the thyroid gland?

A

The inferior thyroid artery

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26
Q

The internal thoracic artery comes from which artery?

A

The subclavian artery (we have one on each side)

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27
Q

What is another name for the internal thoracic artery?

A

The internal mammary arteries

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28
Q

The internal mammary arteries can also be known as ___?

A

The internal thoracic artery

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29
Q

Where does the internal thoracic artery travel?

A

Down within the thoracic cage

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30
Q

The internal thoracic artery travels down within the thoracic cage, and continues down to become what?

A

The superior epigastric arteries

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31
Q

The vertebral, internal thoracic and thyrocervical arteries all arise from where?

A

The subclavian artery in the base of the neck

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32
Q

The subclavian artery gives rise to which arteries?

A

The vertebral, internal thoracic and thyrocervical arteries in the base of the neck.

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33
Q

Slide 5

Identify the following arteries:

  • common carotid
  • subclavian
  • external carotid
  • internal carotid
  • vertebral
  • thyrocervical trunk
  • inferior thyroid
  • internal thoracic
A

See slides

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34
Q

Describe the inferior thyroid artery.

A

It comes off the thyrocervical trunk, curving behind the CCA and supplies the inferior lobe (lower pole) of the thyroid gland.

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35
Q

The suprascapular artery arises from where?

A

The thyrocervical trunk

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36
Q

The suprascapular artery supplies what?

A

The shoulder

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37
Q

The ascending cervical artery arises from where?

A

The inferior thyroid artery

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38
Q

The transverse cervical artery arises from where?

A

The inferior thyroid artery

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39
Q

The transverse cervical artery supplies what?

A

Structures in the neck

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40
Q

The thyrocervical trunk gives off which arteries?

A

The inferior thyroid and the suprascapular arteries.

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41
Q

The suprascapular and the inferior thyroid arteries come from where?

A

The thyrocervical trunk (off the subclavian artery).

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42
Q

The inferior thyroid artery gives off which branches?

A

The ascending cervical and transverse cervical

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43
Q

The ascending cervical artery supplies what?

A

Structures in the neck

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44
Q

The ascending cervical and transverse cervical arise from where?

A

The inferior thyroid artery

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45
Q

Describe the route from the arch of aorta to the ascending cervical artery on the right hand side. Name all the branches each structure gives off.

A
  • Arch of aorta (braciocephalic trunk, left subclavian, left CCA)
  • Brachiocephalic trunk (right subclavian, right CCA)
  • Right subclavian artery (vertebral, internal thoracic, thyrocervical)
  • Thyrocervical trunk (suprascapular, inferior thyroid)
  • Inferior thyroid artery (ascending cervical, transverse cervical)
  • Ascending cervical artery
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46
Q

Slide 6

Label the following arteries.

A

(Top to bottom)

  • Ascending cervical
  • Transverse cervical
  • Suprascapular
  • Inferior thyroid
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47
Q

What do the vertebral and ICA supply?

A

Intracranial structures - hence why they do not give off any branches in the neck, and head straight up into the skull.

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48
Q

The vertebral arteries arise from ___?

A

The subclavian arteries on the left and right

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49
Q

The vertebral arteries travel up the neck how?

A

Through the transverse foramina of cervical vertebrae 6-1

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50
Q

The vertebral arteries travel up the neck via which part of the cervical vertebra?

A

The transverse foramina

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51
Q

The vertebral arteries travel through the transverse foramina of which vertebrae?

A

C6 up to C1

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52
Q

The vertebral arteries enter the skull via the ___?

A

Foramen magnum

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53
Q

The vertebral arteries of each side (left and right) fuse to form ___?

A

The basilar artery

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54
Q

The basilar artery is created by the ___?

A

Left and right vertebral arteries fusing together

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55
Q

The ICA enters the skull via the ___?

A

Carotid canal

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56
Q

Where do the vertebral and ICA enter the skull?

A

Vertebral - foramen magnum

ICA - carotid canal

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57
Q

The ICA after it enters the skull, and the basilar artery, along with other arteries form what?

A

An anastomosing circle of arteries called the circle of Willis in the brain.

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58
Q

What do the vertebral and ICA do?

A

Supply structures within the skull (intracranial structures) i.e. the brain.

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59
Q

Slide 7

Label the:
- vertebral artery
- internal carotid artery
- subclavian artery (right)
- transverse foramina of cervical vertebra
- C1-C6
- foramen magnum
- basilar artery
- carotid canal
(And any other structures)
A
  • Vertebral: runs up through transverse foramina of cervical vertebra
  • ICA: runs up from bifurcation of CCA into skull
  • Subclavian: off brachiocephalic trunk from arch of aorta
  • Transverse foramina: holes in which vertebral artery pass
  • C1-C6: from top to bottom
  • Foramen magnum: place where vertebral artery enters skull
  • Basilar artery: junction where vertebral arteries fuse in skull
  • Carotid canal: where ICA enters skull
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60
Q

What muscle forms the medial border of the carotid triangle?

A

Superior belly of omohyoid

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61
Q

What muscle forms the medial border of the carotid triangle?

A. anterior belly of digastric
B. inferior belly of omohyoid
C. posterior belly of digastric
D. sternocleidomastoid
E. superior belly of omohyoid
A

E. Superior belly of omohyoid

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62
Q

What are the boundaries of the carotid triangle?

A

Superior belly of omohyoid, Sternocleidomastoid, Posterior belly of digastric

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63
Q

What are the boundaries of the carotid triangle?

A. Midline of anterior aspect of the neck, Sternocleidomastoid muscle, Lower border of the mandible
B. Inferior belly of omohyoid, Sternocleidomastoid, Anterior belly of digastric
C. Superior belly of omohyoid, Sternocleidomastoid, Posterior belly of digastric
D. Superior belly of omohyoid, Sternocleidomastoid, Lower border of the mandible
E. Inferior belly of omohyoid, Sternocleidomastoid, Posterior belly of digastric

A

C. Superior belly of omohyoid, Sternocleidomastoid, Posterior belly of digastric

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64
Q

What occurs in the carotid triangle?

A

This is the location of the bifurcation of the CCA into the ICA and ECA.

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65
Q

The CCA bifurcates at which level (roughly)?

A

At the superior border of thyroid cartilage (C4 level)

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66
Q

Where does the IJV lie?

A

Lateral to the CCA, mostly under SCM.

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67
Q

Slide 9 (left)

Label the:

  • superior belly of omohyoid
  • anterior belly of digastric
  • posterior belly of digastric
  • sternocleidomastoid
  • internal jugular vein
  • common carotid artery
  • external carotid artery
  • internal carotid artery
A

See Notability

  • SCM is cut back and reflected to show IJV and CCA
  • ECA has many branches
  • ICA has no branches in the neck
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68
Q

Slide 9 (right)

Label CCA, ICA, ECA and the thyroid cartilage

A

Arrow (CCA)

ICA - No branches

ECA - branches

Thyroid cartilage - grey pentagon

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69
Q

http://www.netanatomy.com/GAs/GAhns/hnGAcommon1si.html

Identify the:

  • carotid triangle
  • its borders
  • IJV
  • ECA
  • ICA (not visible here but locate)
A

See Extra Notes (also website for further information/tests)

*Note: ICA cannot be seen; the IJV would have to be reflected to visualise it!)

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70
Q

Describe the borders of the carotid triangle in detail.

A

Lateral border - anterior border of SCM

Medial border - superior belly of omohyoid

Superior border - posterior belly of digastric

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71
Q

Where does the ICA lie?

A

Behind the IJV, so cannot see it on this cadaver

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72
Q

Bifurcation of the carotid artery is a common site for what?

A

Atheroma formation

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73
Q

Why is the bifurcation of the CCA a common site for atheroma formation?

A

Bifurcation at this point causes turbulence, and where you get turbulence is where you can have an atheroma forming

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74
Q

What do atheromas do to an artery?

A

They cause a narrowing (stenosis) of the artery

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75
Q

How much does the artery need to be narrowed by to cause symptoms?

A

> 70%

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76
Q

What complications can occur from an atheroma

A

Ischaemia - not enough blood getting to the brain

Embolus

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77
Q

Other than ischaemia, what complications can occur from an atheroma?

A

Rupture of the clot can cause an embolus to travel to the brain.

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78
Q

Rupture of an atheromatic clot can cause what?

A

An embolus

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79
Q

How can an embolus in the CCA be a cause of TIA or stroke?

A

If an embolus comes off the ICA, it will travel up the brain, and if it lodges in an artery supplying a region of the brain then it will cause TIA or a thrombotic stroke.

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80
Q

What can an embolus in the CCA be a cause of?

A
  • Transient ischaemic attack (TIA)

- Thrombotic stroke

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81
Q

Slide 10

Describe the picture, and explain how you can get TIA or stroke.

A
  • Bifurcation of the carotid artery causes turbulence
  • Turbulence is a common place for atheroma formation
  • This causes an artery to narrow (stenosis
  • If the artery is stenoses by >70%, then that can cause symptoms such as ischaemia
  • Another complication is an embolus, due to rupture of the clot
  • If this occurs in the ICA, then this can travel straight up to the brain, lodging in an artery there
  • If this artery supplies the brain, then this can be the cause of TIA or stroke
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82
Q

What structures appear at the site of bifurcation of the carotid artery?

A
  • Carotid sinus

- Carotid body

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83
Q

What is the bulge of the ICA, at the bifurcation point, called?

A

Carotid sinus

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84
Q

Where is the carotid sinus?

A

It is a swelling on the ICA at the region of bifurcation.

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85
Q

Where are baroreceptors located?

A

Within the artery wall of the carotid sinus

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86
Q

The carotid sinus is the location for what?

A

Baroreceptors

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87
Q

What are baroreceptors?

A

Pressure sensors for detecting changes in arterial blood pressure

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88
Q

What detects changes in blood pressure?

A

Baroreceptors (found in the carotid sinus)

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89
Q

How do baroreceptors act to change blood pressure?

A

If the blood pressure is higher, then the baroreceptors stretch and send more action potentials to the cardiovascular control centre in the brain.

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90
Q

What does the carotid body do?

A

They are a small cluster of peripheral chemoreceptors which detect arterial oxygen.

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91
Q

What is the carotid body?

A

A cluster of richly vascularised cells (getting a really rich blood supply - they are not in the artery wall)

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92
Q

Where are the chemoreceptors that detect arterial oxygen found?

A

In the carotid body

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93
Q

Describe the similarities and differences between the carotid sinus and carotid body

A

Similarities:
- both occur due to the bifurcation of the carotid artery

Differences (Carotid sinus/Carotid body):

  • Swelling at region of bifurcation/cluster of richly vascularised cells not in the arterial wall
  • Location of baroreceptors/chemoreceptors
  • Detects changes in blood pressure/arterial oxygen
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94
Q

Slide 11

Label the carotid sinus and the carotid body. Describe their structure and function.

A

See slides

Carotid sinus/carotid body:

  • swelling/cluster of cells
  • location of baroreceptors/chemoreceptors
  • arterial BP/arterial O2
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95
Q

Why is the carotid triangle important clinically?

A
  • Surgery, e.g. if someone has an atheroma present and the artery is really narrow (>70%) then may need plaque removed via surgery
  • For reaching the IJV
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96
Q

What is the most appropriate method of removing an atheroma in the carotid artery?

A
  • Patients assessed individually, so many factors will be looked at
  • For some patients, most appropriate treatment is surgery (carotid endarterectomy)
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97
Q

Explain how a surgeon would remove an atheromatous plaque in the carotid artery.

A
  • Find the carotid triangle, as the carotid artery is easily accessible here
  • Surgically open the carotid artery to remove the plaque
  • Stitch it up again
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98
Q

What is a carotid endarterectomy?

A

Carotid endarterectomy is a surgical procedure to remove a build-up of fatty deposits (plaque), which cause narrowing of a carotid artery. (NHS)

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99
Q

What is the name for the surgical procedure which involves a removal of the fatty deposits in a carotid artery?

A

Carotid endarterectomy.

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100
Q

What is an SVT?

A

Supraventricular tachycardia

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101
Q

What is SVT?

A

When the heart is racing because of a problem above the ventricles and atria

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102
Q

What is a treatment for SVT?

A

Carotid sinus massage

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103
Q

What is the physiological mechanism of a carotid sinus massage for patients with SVT?

A
  • The carotid sinus is the location of the baroreceptors.
  • If a patient has SVT, then you want to slow conducting getting through the AVN by increasing vagal tone (reduce the heart rate)
  • Massaging the carotid triangle area allows you to massage over the carotid sinus
  • This activates baroreceptors, which in turn, will enhance vagal input
  • Similarly, the vagal nerve is found in this area so you may be stimulating the vagus nerve directly to increase vagal tone
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104
Q

Which nerves can be accessed in the carotid triangle?

A

The vagus and hypoglossal nerves

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105
Q

Where can the carotid pulse be felt?

A

In the carotid triangle, just below the bifurcation

- may also be palpated more inferiorly

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106
Q

Slide 12

Explain the picture (top)

A

1) Before - plaque - restricted blood flow
2) Plaque is removed
3) After - Normal blood flow

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107
Q

Slide 12

What procedure is this image showing (bottom)?

A

Carotid sinus massage

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108
Q

Where does the ICA enter the skull?

A

Through the carotid canal

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109
Q

Where is the carotid canal?

A

A canal in the petrous part of the temporal bone

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110
Q

What happens to the ICA when it enters the skull through the carotid canal?

A

It immediately turns medially and horizontally

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111
Q

Slide 13

Identify the ICA and carotid canal

A

The artery that arises from the bifurcation point of the CCA, where it enters the skull is the carotid canal. Note how it turns medially and horizontally as it enters the skull.

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112
Q

What is the route of the ICA?

A

It enters the skull through the carotid canal in the petrous part of the temporal bone, then turned medially and horizontally.

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113
Q

What happens to the ICA when it enters the skull?

A

It enters the cranial cavity then makes S-shaped bend - it appears tortuous and curved.

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114
Q

What sort of shape does the ICA make when it enters the cranial cavity?

A

It appears tortuous and curved, making an S-shaped bend

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115
Q

After the ICA makes its S-shaped bend once it enters the cranial cavity, what does it do?

A

It courses through the cavernous sinus

must know this!

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116
Q

Slide 14

What section is the right image taken from?

A

Coronal, see left image

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117
Q

Slide 14

Describe the route of the ICA.

A

Correctly identified:

  • carotid canal
  • temporal bone
  • S-shaped curve of the ICA
  • cavernous sinus
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118
Q

How many cavernous sinuses are there?

A

Two, one on each side

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119
Q

Where does the cavernous sinus sit?

A

Either side of the sphenoid bone, in the sella turcica, where the pituitary gland sits.

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120
Q

Which bone is the cavernous sinus associated with?

A

The sphenoid bone

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121
Q

What is the depression in which the cavernous sinus lies called?

A

The sella turcica

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122
Q

What sits in the sella turcica?

A

The cavernous sinus and the pituitary gland

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123
Q

What is the sella turcica?

A

A depression in the sphenoid bone in which the pituitary gland sits.

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124
Q

What lies either side of the sphenoid bone?

A

The cavernous sinus which is part of the dural venous plexuses

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125
Q

Within the venous plexus, what structures pass through?

A

Many other structures, including:

  • ICA
  • many other cranial nerves
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126
Q

What is found on the upper surface of sphenoid?

A

A plexus of extremely thin-walled veins

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127
Q

What and where is the cavernous sinus?

A

A plexus of extremely thin-walled veins on the upper surface of sphenoid

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128
Q

What structures are found in the cavernous sinus?

A
  • Internal carotid artery
  • CNIII oculomotor
  • CNIV trochlear
  • CNVI abducent
  • 2 branches of trigeminal
  • —- CNV1 ophthalmic and CNV2 maxillary
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129
Q

Which cranial nerves are found in the cavernous sinus?

A

Cranial nerve 3, 4 and 6; plus two branches of cranial nerve 5

i.e. oculomotor, trochlear, abducent and two branches of trigeminal (opthalmic and maxillary)

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130
Q

What is cranial nerve III?

A

Oculomotor

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131
Q

Oculomotor is cranial nerve ___?

A

III (3)

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132
Q

What is cranial nerve IV?

A

Trochlear

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133
Q

Trochlear is cranial nerve ___?

A

IV (4)

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134
Q

What is cranial nerve VI?

A

Abducent

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135
Q

Abducent is cranial nerve ___?

A

VI (6)

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136
Q

What is cranial nerve V?

A

Trigeminal

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137
Q

Trigeminal is cranial nerve ___?

A

V (5)

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138
Q

Which cranial nerve has two branches found in the cavernous sinus?

A

Trigeminal

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139
Q

Which two branches of the trigeminal nerve are found in the cavernous sinus?

A

Ophthalmic and maxillary (CNV1 and CNV2)

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140
Q

What nerves are CNV1 and CNV2?

A

The ophthalmic and maxillary branches of the trigeminal nerve

(Mandibular = CNV3)

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141
Q

What do the oculomotor, trochlear and abducent cranial nerves supply?

A

The muscles controlling the movement of the eye

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142
Q

Which cranial nerves control the movement of the eye?

A

III, IV and VI = oculomotor, trochlear and abducent

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143
Q

Slide 15

What section is this image (bottom)?

A

Coronal section of cavernous sinus (see top image)

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144
Q

Slide 15 (bottom image)

Identify the:

  • cavernous sinus
  • sphenoid bone
  • sella turcica
  • pituitary gland
  • ICA
  • cranial nerves
A
  • CS: blue on each side
  • Sphenoid: cream bone
  • Sella turcica: darker cream depression
  • Pituitary: pink
  • ICA: red
  • CN: yellow
145
Q

What is an arteriogram?

A

An x-ray of arteries

146
Q

How do you take an arteriogram?

A

Put radiopaque dye in carotid system

147
Q

What is radiopaque dye?

A

Dye that does not allow the passage of X-rays or other radiation - allows certain structures to be outlined (e.g. in arteriograms, outlines arterial system).

148
Q

Slide 16

Caption this image

A

Arteriogram of the carotid system, using radiopaque dye

149
Q

Slide 16

Highlight the S-shape of the ICA

A

See Notability

This shows the ICA takes a tortuous course.

150
Q

The ophthalmic artery is a branch of which artery?

A

The ICA

151
Q

The ophthalmic artery is one of the first branches that the ICA gives off when it ______ the _____.

A

Enters the skull

152
Q

The ophthalmic artery runs along with which nerve?

A

The optic nerve (CN II)

153
Q

The ophthalmic artery gives off a branch which supplies the retina of the eye. What is this called?

A

The central retinal artery

154
Q

The central retinal artery supplies what?

A

The retina of the eye

155
Q

The eyeball is supplied by ___?

A

Branches of the ophthalmic artery (a branch of the ICA)

156
Q

The orbit of the eye is supplied by ___?

A

Branches of the ophthalmic artery (a branch of the ICA)

157
Q

The ophthalmic artery branches to supply ___?

A

The retina of the eye, the eyeball and the orbit of the eye.

158
Q

What is the first branch of the ICA?

A

The ophthalmic artery

159
Q

The supratrochlear and supraorbital artery arise from where?

A

The ICA via its first branch, the ophthalmic artery.

160
Q

Slide 17

Identify the:

  • ICA
  • Opthalmic a
  • Optic nerve (CN II)
  • Central retinal a
  • Retina of the eye
  • Supratrochlear a
  • Supra-orbital a
A

See slides (retina is back of eye)

161
Q

Which cranial nerve is the optic nerve?

A

CN II

162
Q

Which is cranial nerve II?

A

Optic nerve

163
Q

How many branches in the neck do the ICA and ECA give off?

A

ICA - 0

ECA - 6 + 2 terminal branches

164
Q

How many branches does the ECA give off?

A

6 + 2 terminal branches.

165
Q

What is the first branch of the ECA?

A

Superior thyroid artery

166
Q

What does the superior thyroid artery supply?

A

The thyroid gland

167
Q

What arteries supply the thyroid gland?

A

The superior thyroid artery and the inferior thyroid artery

168
Q

Where do the superior and inferior thyroid arteries arise from?

A

Superior - first branch of ECA (from CCA)

Inferior - branch of the thyrocervical (from subclavian a)

169
Q

What is the second branch of the ECA?

A

Lingual artery

170
Q

What does the lingual artery supply?

A

The tongue

171
Q

What is the third branch of the ECA?

A

Facial artery

172
Q

Where does the facial artery lie?

A

Goes along the mandible and comes up just in front of the masseter muscle.

The facial artery has several branches.

173
Q

How do you find your facial pulse?

A

Clench your jaw (mandible), feel masseter muscle tense up. Palpate just in front of here, can feel pulse of facial artery.

174
Q

What is the fourth branch of the ECA?

A

Ascending pharyngeal artery

175
Q

Describe the structure of the ascending pharyngeal artery.

A

Tiny branch that ascends up the neck

176
Q

What is the fifth branch of the ECA?

A

Occipital

177
Q

Where does the occipital artery lie?

A

Around the posterior aspect of the scalp

178
Q

What does the occipital artery supply?

A

The scalp

179
Q

What is the sixth branch of the ECA?

A

Posterior auricular

180
Q

Where does the posterior auricular artery lie?

A

It runs up the neck and travels behind the ear, hence the name

181
Q

What does the posterior auricular artery supply?

A

The scalp

182
Q

What are the two terminal branches of the ECA?

A
  • Superficial temporal a

- Maxillary a

183
Q

Describe the superficial temporal artery.

A

It is one of two terminal branches of the ECA. It gives off lots of other branches in the skull which anastomose with other arteries.

184
Q

Where does the maxillary artery lie?

A

Deep behind the mandible

185
Q

The superficial temporal artery and the ________ artery are terminal branches of the ECA.

A

Maxillary

186
Q

Slide 18

Identify the 6 branches of the ECA and the 2 terminal branches.

Label the other arteries for bonus points

A

See slides

Note: Maxillary artery has a marking at the posterior of the skull and a small red arrow deep to the maxilla.

187
Q

What is the blood supply to the scalp?

A
  • Supraorbital
  • Supratrochlear
  • Superficial temporal
  • Posterior auricular
  • Occipital
188
Q

How is blood supplied to the scalp?

A

By branches of the ECA and ICA anastomosing over the head and giving blood supply to the scalp.

189
Q

What are the branches of the ECA that supply blood to the scalp?

A
  • Superficial temporal
  • Posterior auricular
  • Occipital
190
Q

What are the branches of the ICA that supply blood to the scalp?

A
  • Supraorbital

- Supratrochlear

191
Q

Where do the supraorbital and supratrochlear arteries come from?

A

Branches of the ophthalmic artery from the ICA.

192
Q

The superficial temporal, posterior auricular and occipital arteries are branches of ___?

A

The ECA

193
Q

Slide 19 (left)

Identify roughly the following arteries:

  • Supraorbital
  • Supratrochlear
  • Superficial temporal
  • Posterior auricular
  • Occipital
A

See slides

194
Q

Slide 19 (right)

Identify the following arteries:

  • Supraorbital
  • Supratrochlear
  • Superficial temporal
  • Posterior auricular
  • Occipital
A

See slides

195
Q

Describe the blood supply to the scalp.

A

Rich blood supply with many anastomoses.

196
Q

The blood supply to the scalp is largely branches of ___.

A

ECA

197
Q

The blood supply to the scalp is largely branches of ___ except for the _____________ and ___________ arteries, which arise from ___?

A

ECA; supratrochlear and supraorbital; ICA (via its first branch ophthalmic a)

198
Q

Slide 20

Label the different arteries

A
  • Supratrochlear
  • Supraorbital
  • Superficial temporal
  • Posterior auricular
  • Occipital
    (See slides)
199
Q

Which layer of the scalp do the blood vessels lie?

A

In the dense connective tissue layer, the subcutaneous connective tissue layer

200
Q

What are the different layers of the scalp?

A
  • Skin
  • Connective tissue (dense)
  • Aponeurosis
  • Loose connective tissue
  • Periosteum (CT on the bone)
201
Q

The subcutaneous connective tissue layer of the scalp is which layer and holds what?

A

Connective tissue (dense) [second layer from superficial to deep] and holds blood vessels.

202
Q

Slide 21

Name the layers of the scalp

A
  • Skin
  • Connective tissue (dense)
  • Aponeurosis
  • Loose connective tissue
  • Periosteum
203
Q

What is the clinical relevance of blood supply to the scalp?

A

Because the walls of arteries are closely attached to connective tissue, if there’s a cut, it tends to pull them apart and limits constriction of arteries.
The structure of the scalp means that a cut to the scalp can lead to profuse bleeding

204
Q

Why do anastomoses lead to profuse bleeding on a cut to the scalp?

A

Due to numerous anastomoses on the scalp, it’s difficult to apply pressure to the vessels to stop the bleeding, leading to profuse bleeding.

205
Q

Why does the epicranial aponeurosis lead to profuse bleeding on a cut to the scalp?

A

The occipitalis and frontalis muscles are connected via the epicranial aponeurosis. However, these two muscles (collectively, occipitofrontalis) are pulling in different directions. This can actually pull a cut open to make it worse and bleed more profusely, so deep lacerations involving the epicranial aponeurosis can cause profuse bleeding due to the opposing pull of occipitofrontalis.

206
Q

Why can a cut to the scalp lead to profuse bleeding?

A
  • Arteries closely attached to connective tissue: this limits constriction so profuse bleeding can occur
  • Numerous anastomoses: makes it difficult to apply pressure to stop the bleeding
  • Epicranial aponeurosis (occipitofrontalis): opposing pull of muscle can pull the vessels open and make the cut worse
207
Q

Why does loss of scalp tissue not lead to bone necrosis?

A

The blood supply to the scalp is different to the blood supply to the skull (middle meningeal artery) - so those that suffer scalp injuries alone will not endure necrosis of bone.

208
Q

What is the main blood supply to the skull?

A

Middle meningeal artery

209
Q

What can happen to the skull if you have a scalp injury?

A

Nothing, you will not get bone necrosis because the blood supply to the skull is differently to the blood supply to the scalp. (Blood supply to the skull is mostly the middle meningeal artery.)

210
Q

Slide 22

What is the arrow indicating?

A

Epicranial aponeurosis

211
Q

What are the superficial arteries of the face?

A
  • Facial
  • Supraorbital
  • Supratrochlear
  • Superior & inferior labial
  • Angular
  • Lateral nasal
212
Q

The facial artery comes off which artery?

A

ECA

213
Q

The facial artery gives off which arteries around the lips?

A

Superior & inferior labial arteries

214
Q

Where do the superior and inferior labial arteries arise?

A

From the facial artery

215
Q

All the superficial arteries of the face arise from the ECA except the ___ and ___?

A

Supraorbital and supratrochlear - these are from the ICA (via ophthalmic).

216
Q

The facial artery gives off which arteries around the nose?

A
  • Angular

- Lateral nasal

217
Q

Slide 23

Label the structures. Which of these two structures supply deeper structures?

A
  • Supraorbital
  • Supratrochlear
  • Transverse facial
  • Angular
  • Lateral nasal
  • Maxillary
  • Superior & inferior labial
  • Facial

The transverse facial and maxillary supply deeper structures.

218
Q

Where can the facial artery pulse be felt?

A

At the inferior border of the mandible, anterior to the masseter muscle.

219
Q

What do the branches of the maxillary artery supply?

A

The maxillary artery has many branches supplying muscles and deeper structures in face

220
Q

What are the two branches of the maxillary artery need to know?

A

Sphenopalatine
Middle meningeal

Need to know

221
Q

What does sphenopalatine artery supply?

A

An anastomosis to the nasal septum

222
Q

What does the middle meningeal artery supply?

A

Blood to the skull and the dura

223
Q

Sphenopalatine is a branch of which artery?

A

Maxillary

224
Q

Middle meningeal is a branch of which artery?

A

Maxillary

225
Q

Slide 24

Label the following arteries:

  • Sphenopalatine
  • Middle meningeal

and Maxillary (1st part)

A

See slides

226
Q

Which arteries supply the nasal septum?

A
  • Septal branch of sphenopalatine artery
  • Anterior ethmoidal arteries

(There are others, e.g. posterior ethmoidal, septal branch of labial artery etc., but you do not need to know them!)

227
Q

How is the blood supply to the nasal septum arranged?

A

Arteries supplying the septum anastomose in Kiesselbach’s area

228
Q

What is Kiesselbach’s area?

A

An anastomosis of blood vessels in the nasal septum

229
Q

Where does the sphenopalatine artery come from?

A

The maxillary artery

230
Q

Where does the anterior ethmoidal artery come from?

A

The ophthalmic artery

231
Q

What is the medical terminology for a nose bleed?

A

Epistaxis

232
Q

What is epistaxis?

A

A nosebleed

233
Q

Describe how the sphenopalatine artery relates to nose bleeds.

A

This artery joins with other arteries (such as the anterior ehtmoidal) to anastomose in the nasal septum. They anastomose in an area called Kiesselbach’s area, which because of the rich blood supply, is a common site for nosebleeds.

234
Q

What is the clinical relevance of Kiesselbach’s area?

A

It is a site of anastomosis in the nasal septum, and because of this, is a common site for epistaxis (nosebleeds) - the anastomosis makes it difficult to stop that nosebleed.

235
Q

Slide 25

Label the diagram.

A

See slides

Important is *Sphenopalatine

  • Anterior ethmoidal
  • Kiesselbach area
236
Q

What is the blood supply to the skull and the dura that surrounds the brain?

A

The middle meningeal artery

237
Q

The middle meningeal artery is a branch of the ___?

A

Maxillary artery

238
Q

Where does the middle meningeal artery pass (in relation to the skull)?

A

Deep to the zygomatic arch

239
Q

What does the middle meningeal artery split into and where?

A

Inside the skull, it splits into the anterior and posterior branch (of the middle meningeal artery)

240
Q

The frontal, parietal, temporal and sphenoid bones join together. What is this region called?

A

The pterion

need to know

241
Q

What is the pterion?

A

The region where the skull bones join together

242
Q

Why is the pterion clinically significant?

A

The pterion is a particularly thin area of skull where the bones of the skull join together. The middle meningeal artery also courses over this.

This means that if you get a blow to the side of the head at this region, the middle meningeal artery can be damaged, as this area of the skull is a little bit thinner and more easily damaged.

243
Q

Slide 26 (left)

Label the:

  • maxillary a
  • middle meningeal a
  • anterior branch of middle meningeal a
  • posterior branch of middle meningeal a
  • pterion
A

See slides

anterior and posterior branches are shaded paler to represent they are inside the skull

244
Q

Slide 26 (right)

Identify the pterion

A

See slides

where the skull bones join together

245
Q

Where does the middle meningeal artery enter the skull?

A

Through the foramen spinosum

246
Q

Slide 27

  • Identify the foramen spinosum.
  • Identify the grooves made by the middle meningeal artery
A

See Notability

247
Q

Describe the landmark made by the middle meningeal artery in the skull.

A

It makes grooves in the skull as it supplies the skull, after it enters through the foramen spinosum.

248
Q

What does the middle meningeal artery supply?

A

The skull and the dura

249
Q

What is the brain covered by?

A

A double layer of dura mater - one layer is attached to the skull (periosteum)

250
Q

Describe the two layers of dura mater attached to the skull.

A

One layer is attached to the skull as periosteum

251
Q

Slide 28 (left)

  • Label the arrows
  • Identify the covering of the skull
A

Arrows: anterior branches of middle meningeal artery

Brain covered by double layer of dura mater (shown by window)

(See Notability)

252
Q

Slide 28 (right)

  • Label the red arrows
  • Caption the image by its view
  • Describe how this view was taken
A
  • Coronal suture
  • Grooves formed by anterior branch of middle meningeal artery

Caption: Internal view of calvaria (skull)

The view of this skull is taken as if you’ve taken the top bit of the skull off and looking inside at the concave bit.

253
Q

What does “calvaria” mean?

A

Skull

254
Q

What is the Latin name for skull?

A

Calvaria

255
Q

What does the middle meningeal artery supply?

A

The skull and dura

256
Q

Where is a common site of middle meningeal artery rupture?

A

At the pterion

257
Q

Where can you fracture the skull?

A

At the pterion

258
Q

Fracture of skull at pterion can ___?

A

Rupture the middle meningeal artery

259
Q

What happens if the middle meningeal artery ruptures?

A

Blood comes out, which actually peels the dura off the skull

260
Q

What are the two layers of dura?

A
  • Layer attached to the skull

- Layer surrounds the brain

261
Q

What is an extradural haemorrhage?

A

When bleeding occurs between the tough outer layer of the skull and the brain i.e. outside the dura.

For example, fracture of the skull at pterion can rupture the middle meningeal artery, pulling the dura away from the skull, causing a haemorrhage in the space between the skull and the dura.

(See extra notes for full explanation if not understood)

262
Q

How would an extradural haemorrhage appear in a CT scan of the brain?

A

There would be a crescent-shaped protrusion of the outer edges of the skull where blood has pooled - however, the blood is limited by the dura so does not extend further.

263
Q

Slide 29 (left)

Explain what the left image is showing. The portion of the skull shown is the pterion.

A
  • Fractures of the skull at the pterion can rupture the middle meningeal artery.
  • This peels the dura away from the skull (thin light pink layer) as blood pools.
  • However, the blood is limited by the dura (double layer - thin light pink and thin light yellow) so does not touch the brain.
  • Note the crescent shape the blood makes.
264
Q

Slide 29 (right)

Explain what the image is showing.

A
  • This is a CT scan of the brain.
  • The scan is showing an extradural haemorrhage in a patient.
  • This is characterised by the crescent-shaped protrusion at the edges.
  • The crescent-shape is present because fractures of the skull, particularly at the pterion, at the side of the head (as in this image), fracture the middle meningeal artery
  • This then peels the dura away from the skull.
  • However, the blood is limited by the dura so does not extend into the skull, and therefore forms the crescent-moon shape (the dura which formerly attached to both skull and brain is now being pushed so there is now skull –> blood –> both dural layers –> brain)
265
Q

What is a craniotomy?

A

Surgery to cut a bony opening in the skull

266
Q

How can a surgeon gain access to the cranial cavity?

A

By performing a craniotomy

267
Q

What is the cranial cavity?

A

Space within the skull

268
Q

How is a craniotomy performed?

A

The bon and scalp flap is reflected inferiorly to preserve the blood supply by keeping the arteries intact (?)

269
Q

Slide 30

Label the image

A
  • Dura mater
  • Bone flap
  • Scalp & muscle
270
Q

In venous drainage of the scalp - what do the superficial veins generally do (as is typical).

A

They generally accompany arteries of the same name.

271
Q

What are some of the superficial veins of the scalp?

A
  • Superficial temporal veins
  • Occipital veins
  • Posterior auricular veins
272
Q

The superficial veins of the scalp general accompany arteries of the same name. Name some of these.

A
  • Superficial temporal
  • Occipital
  • Posterior auricular
273
Q

Name some veins of the scalp which drain a different direction to their respective arteries.

A
  • Supraorbital vein

- Supratrochlear vein

274
Q

How do the supraorbital and supratrochlear arteries and veins differ?

A

The arteries came as branches off the ICA and ophthalmic.

The veins, instead of following the same direction, unite at the medial angle of the eye to form an angular vein, which drains into the facial vein.

275
Q

Where are the supraorbital and supratrochlear veins found?

A

These unite at the medial angle of the eye to form an angular vein, which drains into the facial vein.

276
Q

Which vein does the supraorbital and supratrochlear vein drain into?

A

The facial vein

277
Q

Where are some of the deep veins in the scalp found?

A

In the temporal region

278
Q

Some of the deep parts of the scalp in the temporal region have veins which drain where?

A

Into the pterygoid venous plexus.

279
Q

Slide 32

Explain what this image is showing.

A

Venous drainage of the scalp.

Note: the diagram is only showing the skull - but imagine there is scalp etc. there

280
Q

Slide 33

Identify the following veins:

  • supraorbital
  • supratrochlear
  • angular
  • facial
  • superficial temporal
  • occipital
  • posterior auricular

Any other veins

A

See Notability

281
Q

Structures that drain the brain drain into where?

A

Structures called dural venous sinuses.

282
Q

Cerebral veins drain where?

A

Into dural venous sinuses

283
Q

What are dural venous sinuses?

A

Essentially venous channels covered in dura

284
Q

Where are dural venous sinuses found?

A

Between the double layer of dura (i.e. between the dura that covers the brain and between the dura under the bone of the skull)

This occurs at certain parts of the skull - the dura separates to form venous sinuses.

285
Q

Most of the venous drainage to the skull is going to drain into the dural venous sinuses. What else drains here?

A

Emissary veins which go from the scalp and drain through into the dural venous sinus.

286
Q

How does venous drainage of the scalp enter the dural venous sinus?

A

Via emissary veins

287
Q

What are emissary veins of the skull?

A

These connect venous drainage of the scalp to the dural venous sinuses.

288
Q

What are veins of the skull called?

A

Diploic veins

289
Q

How do the veins of the scalp connect to the diploic veins of the skull (and thus to dural venous sinuses)?

A

Via several emissary veins

290
Q

What is a distinctive component of emissary veins?

A

They are valveless

291
Q

Emissary veins are valveless. What does this mean for blood flow?

A

Blood can move in either direction.

292
Q

Why can blood move in either direction for emissary veins?

A

Because they are valveless.

293
Q

Why are emissary veins important to know about clinically?

A

They can act as a route for infection from the scalp to the cranial cavity.

If serious, this can lead to meningitis.

294
Q

How can an infection in the scalp spread to the cranial cavity?

A

Via emissary veins which connect the scalp to the skull, allowing blood to travel and therefore infections.

295
Q

What is a complication of an infection in the dural venous sinus?

A

The infection can get into the cranial cavity and affect the meninges covering the brain - leading to meningitis.

296
Q

Slide 33

Label the diagram (include the hemispheres of the brain)

A

See Slides/Notability

297
Q

Slide 34

Label the veins depicting venous drainage of the face

A
  • Supraorbital
  • Supratrochlear
  • Angular
  • Superior & inferior labial
  • Facial
  • Common facial
  • Internal jugular
  • External jugular
298
Q

Describe the path from the supraorbital and supratrochlear veins to the internal jugular vein

A

Supraorbital/supratrochlear –> angular –> facial –> common facial –> IJV

299
Q

Describe the path from the superior & inferior labial veins veins to the internal jugular vein

A

Superior & inferior labial veins –> facial –> common facial –> IJV

300
Q

Slide 34

Identify the superficial temporal vein and comment on its drainage

A

See Notability

You can get a little bit of variability in the superficial temporal vein - part of it comes down into the IJV but it also drains into the EJV

301
Q

What is a structural components of veins of the face?

A

They are valveless

302
Q

Slide 34

Label the cavernous sinus

A

See Notability

pale plexus of veins in skull

303
Q

As well as drainage of the eye coming down towards the facial vein, where else can these veins drain?

A

Back towards the cavernous sinus

304
Q

What does the cavernous sinus hold (other than veins)?

A

The internal carotid artery, either side of the sphenoid bone

305
Q

Where is the cavernous sinus?

A

Either side of the sphenoid bone.

306
Q

Which veins around the orbit can drain back to the cavernous sinus?

A

The superior and inferior ophthalmic veins

307
Q

Where can deep facial veins drain into?

A

The pterygoid venous plexus

308
Q

Where is the pterygoid venous plexus?

A

Extracranial - i.e. not in the cranial cavity

309
Q

How are the pterygoid venous plexus and cavernous sinus connected?

A

Via emissary veins

310
Q

The pterygoid venous plexus connects to which other plexus via emissary veins?

A

The cavernous sinus

311
Q

Why are the emissary veins connecting the pterygoid venous plexus and the cavernous sinus clinically important?

A
  • This allows for a route of infection from the superficial face into the intracranial cavity
  • If there is a clot (infected) in the facial vein that can travel to the cavernous sinus
  • This can be from the infections travelling to the the deep facial veins, which travel to the pterygoid venous plexus and travel up via emissary veins to the cavernous sinus
  • Or the clot from the facial vein can travel up towards the superior ophthalmic vein, where it can enter the cavernous sinus directly

Note that this is RARE but can happen.

Veins in the face are valveless and therefore travel both direction!

312
Q

Which veins communicate at the medial angle of the eye?

A

The superior ophthalmic and facial veins

313
Q

What is the significance of veins in the face being valveless?

A

The blood can drain in both directions

314
Q

Infection from the facial vein can spread where?

A

To dural venous sinuses e.g. cavernous sinus

315
Q

What is thrombophlebitis?

A

An inflammatory process that causes a blood clot to form and block one or more veins.

316
Q

What can occur if you get thrombophlebitis of the facial vein?

A
  • Thrombophlebitis is an inflammatory process, causing a blood clot to block 1(+) vein(s).
  • The infected clot can travel around the veins of the face (as these are valveless)
  • This can either travel to the pterygoid venous plexus, which travels to the cavernous sinus via emissary veins; or up to the medial angle of the eye, where it meets the superior ophthalmic vein which drains directly into the cavernous sinus
  • This means thrombophlebitis (blood clots of the vein) can travel to the intracranial venous system and cause infections here
  • Note, these complications are rare but can occur and are serious
317
Q

Slide 35

Label the arrows

A
  • Superior ophthalmic v
  • Cavernous sinus
  • Inferior ophthalmic v
  • Pterygoid venous plexus
  • Facial v
  • Deep facial v’s
318
Q

Why is it important that the cavernous sinus does not get infected?

A

Has many structures in it

  • ICA
  • number of cranial nerves

as well as close it it
- pituitary gland

It is also a sinus draining the brain.

319
Q

Slide 36

Looking at the image - why might a cavernous sinus infection be serious?

A

The cavernous sinus (a plexus of extremely thin-walled veins on upper surface of sphenoid)

holds the

  • ICA
  • oculomotor n
  • trochlear n
  • abducent n
  • – ophthalmic and maxillary branch OF trigeminal n

(It is also close to the pituitary gland and is a sinus draining the brain)

320
Q

What is the danger triangle of the face?

A

The danger triangle is where the facial vein can drain back into the cavernous sinus.

321
Q

Why is it clinically important to know about the danger triangle?

A

Infections in this region can spread through the venous system (via the facial nerve) to the dural venous sinuses (cavernous sinus)

322
Q

Which area of the face are infections most likely to spread back to the cavernous sinus?

A

The danger triangle (from bridge of nose to corners of mouth)

323
Q

Slide 37

What is this triangle called and why is it important?

A

The danger triangle - superficial infections of the face in this triangle can spread deep intracranially into the dural venous sinuses

324
Q

What are dural venous sinuses?

A

Sinuses where the cerebral veins drain into

325
Q

Where do veins from the brain drain into?

A

Cerebral veins drain into dural venous sinuses

326
Q

What is the venous drainage of the brain?

A

Dural venous sinuses

327
Q

Where do the superior and inferior sagittal sinuses join?

A

At the posterior head, where there is a confluence of isnuses, including the transverse sinus.

328
Q

Where does the sigmoid sinus head out of the skull

A

A hole in the bottom of the skull called the jugular foramen

329
Q

The sigmoid sinuses leave the skull via the _____ and continue as the ___

A

jugular foramina; IJV

330
Q

Slide 38

Label the diagrams

A

See slides

331
Q

Slide 38

Identify where the superior and inferior sagittal sinuses meet on both images.

Identify the jugular foramen (right image)

A

See Notability

332
Q

Slide 38

What plane of the head are these cross-sections taken in?

A

Left - sagittal

Right - transverse(?)

333
Q

What is the route of the superior sagittal sinus into the neck?

A

Superior sagittal sinus –> confluence of hte sinuses –> transverse sinus –> sigmoid sinus –> leaves neck at jugular foramen –> internal jugular vein

334
Q

How does the superior sagittal sinus reach the neck?

A

It leaves the skull via the jugular foramen from the sigmoid sinus

335
Q

Where does the facial vein drain into?

A

IJV

336
Q

Where does the superficial temporal vein drain into?

A

IJV

337
Q

Where does the EJV drain into?

A

Subclavian vein

338
Q

Slide 39

Label this image of venous drainage of the head

A
  • Superior sagittal sinus
  • Superficial temporal v.
  • Cavernous sinus
  • Confluence of the sinuses
  • Transverse sinus
  • Sigmoid sinus
  • Facial v.
  • External, Internal and Anterior Jugular vv.
  • Suprascapular v.
  • Left brachio-cephalic v.
  • Subclavian v.
    (See Slides)
339
Q

Which veins run in association with SCM?

A

The EJV runs over SCM and the IJV is hidden by it.

340
Q

EJV runs over which muscle?

A

SCM

341
Q

IJV runs ____ to which muscle?

A

deep/under; SCM

342
Q

Which vein is easier to see - EJV or IJV?

A

EJV

343
Q

Which vein do we use to measure jugular venous pressure, and why?

A

IJV - comes directly down to join the brachiocephalic vein, so is a better indication of pressure in the right atrium.

344
Q

Why don’t we use EJV to measure JVP, rather than IJV?

A

Although EJV is easier to see, IJV comes directly down to join the brachiocephalic vein, so is a better indication of pressure in the right atrium.

345
Q

Slide 40

Label the diagram. Include the brachiocephalic vein.

A
  • SCM
  • EJV (both sides)
  • IJV
  • CCA

(See Notability)

346
Q

Answer specifically - which vein do we use to measure jugular venous pressure?

A

The right internal jugular vein

347
Q

How do we measure right atrial pressure?

A

By looking at the pulse in the right internal jugular vein (jugular venous pressure) - this is effectively a direct connection to the right atrium

348
Q

How do we position patients clinically to measure jugular venous pressure?

A
  • The patient needs to be sat at a 45 degree angle
  • Their head needs to be turned to the left, so we can see the SCM muscle on their RIGHT-hand side (to view the right IJV)
349
Q

How do you measure JVP clinically?

A
  • You measure the height you get pulsations of the IJV from the sternal angle + 5cm
350
Q

How do you look for JVP clinically?

A
  • You are looking for pulsations occurring under/through the SCM muscle - IJV is largely hidden by SCM
  • Although the EJV is much more visible - avoid looking at that and look for pulsations you see
351
Q

What is JVP measured in?

A

cmH2O

352
Q

Describe how you would measure JVP.

A
  • Put patient at 45 degree incline
  • Tilt head slightly to left, to visualise right SCM and IJV
    (Right IJV is directly connected to the right atrium)
  • Visualise pulsations through the muscle
  • Measure the height of these pulsations from the sternal angle + 5cm
  • This is your JVP in cmH2O
353
Q

Slide 41

Label the diagram and the angle for measuring JVP.

Explain how JVP is measured.

A

See slides

354
Q

IMAGE

See extra info, Fig. 3
Label IJV, EJV and SCM

A
  • IJV hidden by SCM

- EJV easily visible

355
Q

Summary

Describe the carotid triangle

A

remember this - it is important!

  • boundaries
  • relevance
356
Q

Summary

Describe the carotid sheath

A
  • Contents

- Location

357
Q

Summary

Describe the blood supply to the scalp

A
  • Many anastomoses

- Deep lacerations = profuse bleeding

358
Q

Summary

Describe the venous route for spread of inections

A
  • Scalp to cranial cavity via emissary veins

- Face to cavernous sinus via inf. & sup. ophthalmic veins & deep facial veins