Vascular Anatomy

Question 1

Segments of the Carotid Artery.

Answer 1

C1(cervical) - Pars cervicalis.

C2(petrous) - Pars petrosa up to the end of the carotid canal.
C3(lacerum) - Up to a ligament between lingula sphenoidales and the apex of the os petrosum.

C4(cavernous) - In the sinus cavernousos until exiting the dura below clinoid processous.

C5(clinoid) - Between anterior clinoid process and the base of os sphenoidale.

C6(opthalmic) - up to the outlet of posterior communicating artery; outlet of the opthalmic artery.

C7(communicating) - Up to the bifurcation of the Carotis interna into the cerebri anterior and cerebri media.

Question 2

Segments of the anterior cerebral artery.

Answer 2

A1 - Pars precommunicalis; from its origin to the outlet of the anterior communicating artery.

A2 - Pars postcommunicalis; from the outlet of anterior communcating artery to the outlet of the callosomarginal artery

A3 - Pars postcommunicalis; distally of the outlet of the callosomarginal artery

Question 3

Segments of middle cerebral artery

Answer 3

M1 - Pars sphenoidalis; from its outlet to the bifurcation in two or three main branches.

M2 - Pars insularis; in the fossa lateralis above the insula

M3 - Pars opercularis; in the foss lateralis, lateral branches in the direction of the cortical surface.

M4 - Pars terminalis; after the exit of all vessels from the sulcus lateralis

Question 4

Branches of the external carotid

Answer 4

1. Sup thyroid artery: 1st anterior branch
2. Ascending pharyngeal artery:
   a) neuromeningeal trunk: supplies IX, X, XI (risk when embolizing glomus tumors)
   b) pharyngeal branch: usually primary feeder of jugular foramen tumors.
3. Lingual artery.
4. Facial artery: Branches anastamose with opthalmic artery.
5. Occipital artery: posterior scalp.
6. Posterior auricular
7. Superficial temporal - frontal branch, parietal branch.
8. Maxillary artery: intially within parotid gland.
   a) middle meningeal artery
   •anterior branch
   •posterior branch
   b) accessory meningeal
   c) inferior alveolar
   d) infra orbital
   f) others.

Question 5

Branches of internal carotid

Answer 5

1. Caroticotympanic and pterygoid (vidian) only in 30% these come from C3
2. Meningohypophyseal it has 3 branches.
   •Artery of tentorium(artery of Bernasconi & Cassinari)
   •Dorsal meningeal
   •Inferior hypophyseal (posterior lobe of pituitary) Sheehan syndrome
3. Anterior meningeal artery
   •Artery to inferior portion of cavernous sinus(only in 80%)
   •Capsular artery of McConnell(only in 30% supply to capsule of pituitary)
4. Opthalmic artery: Origin distal to cavernous sinus in 89%, intracavernous in 8% and absen in 3%. Has a bayonet shape.
5. Superior hypophyseal artery.
   Supplies ant lobe of pit and stalk.

Question 6

Contents of cavernous sinus

Answer 6

From superior to inferior:
Oculomotor III
Trochlear IV
Opthalmich and maxillary branches of trigeminus V
Abducens nerve VI
Internal carotid artery

Question 7

How often arises the opthalmic artery from the middle meningieal artery? What is the risk?

Answer 7

0,5% of cases. Increased risk of blindness in case of an mma embolization.

Question 8

Posterior cerebral artery segments

Answer 8

P1: Precommunicating segment - Extends from the tip of the basilar artery to PCOM origin (within the interpeduncular cistern)
P2: Ambient segment - Extends from the PCOM to the dorsal aspect of the midbrain.
P3: Quadrigeminal segment - Extends from the lat portion of the quadrigeminal cistern to the anterior limit of the calcarine fissure
P4: Terminal cortical branches

Question 9

Vertebral artery branches

Answer 9

Arises from the subclavian artery. Enters foramina transversum at C6 (90%)
1. Extracranial
a) segmental spinal branches
b) muscular branch
c) meningeal branch
2. Post spinal artery
3. Anterior spinal artery
4. PICA.

Question 10

Basilar artery branches

Answer 10

1. Anterior Inferior Cerebellar artery
2. Labyrinthine artery
3. Paramedian artery
4. Superior cerebellar artery
5. Posterior cerebral arteries