(2.1) Vasculatures

Question 1

What are the branches of External Carotid Arteries? Where do they largely supply?

Answer 1

• Superior Thyroid
• Ascending Pharyngeal
• Lingual
• Facial
• Occipital
• Posterior Auricular
• Maxillary
• Superficial Temporal
• Supply face & extracranial structures

Question 2

What is the largest blood supply to the Skull? Through which foramen does it travel through? Where is this artery most at risk of injury?

Answer 2

• Middle Meningeal Artery, a br. of Maxillary
• Through Foramen Spinosum in Sphenoid Bone
• Pterion, may lead to Extradural Haematoma

Question 3

What is an Extradural Haematoma? How may it occur?

Answer 3

• Collection of blood between the cranium & periosteal layer of dura mater
• Laceration to Middle meningeal artery, e.g. fracture at Pterion

Question 4

What are the supplies to intracranial structures? Through which foramina these arteries go through?

Answer 4

• Internal Carotid Artery via Carotid Canal in Temporal bone

- Vertebral A via Foramen Transversaria -> Basilar Artery via Foramen Magnum in Occipital Bone

Question 5

What are the blood supplies to the Scalp?

Answer 5

• External Carotid -> Occipital & Posterior Auricular & Superficial Temporal
• Internal Carotid -> Opthalmic -> Supra-trochlear & Supra-orbital

Question 6

Where is the Carotid pulse taken?

Answer 6

• Between larynx & middle 1/3 sternocleidomastoid

Question 7

Where does the Right and Left Common Carotid Arteries each arise from? Where do they split?

Answer 7

• R: from Brachiocephalic Trunk
• L: from Aortic Arch
• Split at C4, within Carotid Sheath, only the Internal Carotid A carries on within the sheath

Question 8

Where can Temporal pulse be felt?

Answer 8

Superior to Zygomatic Arch of Temporal Bone

Question 9

Why is the Left common carotid artery longer than the right one?

Answer 9

Left originates from Aortic Arch, whereas Right originates from Brachiocephalic Trunk

Question 10

Where is the Carotid Sinus? What structure is located at it? What is their function?

Answer 10

• Dilated area of Internal Carotid Artery, just above the common carotid artery splits
• Baroreceptors detect pressure within it

Question 11

Through which nerve does the Baroreceptor sends its feedback?

Answer 11

Glossopharyngeal Nerve

Question 12

Where is the Carotid Body? What structure is located at it? What is their function?

Answer 12

• Deep in medial side of Bifurication

- Peripheral chemoreceptors detect pO2 & pCO2 here

Question 13

What structures travel through the Parotid Gland?

Answer 13

• Maxillary & Superficial Temporal A
• Facial N
• Retromandibular V

Question 14

Where does the Vertebral Artery arise? Through which foramina does it travel through?

Answer 14

• Subclavian artery
• Foramen Transversaria in Transverse processes of Cervical vertebrae -> becomes Basilar artery -> Foramen Magnum of Occipital bone

Question 15

Where do Internal, External and Anterior Jugular veins arise from?

Answer 15

Subclavian veins which is arised from Brachiocephalic veins

Question 16

Where does the veins in neck drain into?

Answer 16

Anterior Jugular Veins

Question 17

What are Dural Venous Sinuses? Name some of them.

Answer 17

• Endothelial lined spaces between Epiosteal & Meningeal layers of Dura Mater, they are valveless
• Superior Sagittal
• Inferior Sagittal
• Cavernous
• Transverse
• Sigmoid

Question 18

Where is a common site of the Carotid Artery to form Atheroma? What can it result in?

Answer 18

• Bifurcation of the Carotid Artery due to turbulent flow

- Stenosis or Thrombosis can cause stroke/transient ischaemic shock

Question 19

How might you be able to differentiate the Internal & External arteries from an x ray?

Answer 19

Internal artery is lack of branches in the neck, as it ascends into supply intracranial structures

Question 20

What do the Facial & Superior Opthalmic Veins drain into at the medial angle of the eye?

Answer 20

Cavernous Sinus

Question 21

What structure do the deep facial veins drain into?

Answer 21

Pterygoid Plexus

Question 22

Suggest why an infection in deep Pterygoid region be dangerous to the eye?

Answer 22

• Pterygoid plexus infected -> pus accumulation -> direct increase in pressure of Opthalmic V
• Pterygoid -> Deep V -> Cavernous sinus Thrombophlebitis
• Both cause paralysis of Extraocular muscles

Question 23

What nerves may be in danger during a carotid arteriogram puncture?

Answer 23

• Vagus & its branches

- Sympathetic chain

Question 24

Suggest some possible causes of an infection of Cavernous sinus (3). What may be the complications (2)?

Answer 24

• Laceration of dangerous area (upper lip to nasal bridge)
• Laceration underneath the orbit area
• Both result in Thrombophlebitis of Facial Vein -> Superior Opthalmic V -> Cavernous Sinus

Complications

• Infections spread to surrounding nerves (NC III, IV, Vi, Vii, VI)
• Thrombophlebitis of Cavernous DURAL sinus -> intracranium -> Meningitis

Question 25

Where is the Sternal Angle, and what anatomical landmarks does it make?

Answer 25

• Anteriorly: Manubriosternal joint (2nd rib)
• Posteriorly: T4/5 Intervertebral disc
• Separates Ascending Aorta, Aortic Arch, Descending Aorta
• Separates superior & inferior Mediasternum
• Marks Tracheal bifurcation
• Marks end of Azygous system
• Marks Thymus gland