Internal Carotid Artery Flashcards
(35 cards)
What are the 7 segments of the ICA? And their branches
C1 Cervical
C2 Petrous: Vidian artery and carotico tympanic artery, mandibular artery
C3 Lacerum
C4 Cavernous: Posterior trunk (inferior/ meningohypophyseal artery) and inferolateral trunk
C5 Clinoid: Clival artery
C6 Opthalmic: Ophtalmic artery and superior hypophyseal arteries
C7 Communicating: Anterior choroidal artery
Posterior communicating artery
What are the embryonic precursors of the internal carotid artery?
C1: Fetal 3rd aortic arch
C2-C7: Dorsal aortae
Give the average diamters of the ff:
- Common Carotid artery
- Carotid bulb
- ICA distal to bulb
- 7mm
- 7.5 mm
- 4.7 mm
What are the contents of the carotid sheath?
Common carotid artery (C1 ascending segment)
Internal jugular vein
Lymph nodes (Jugulodigastric nodes of the high deep cervical chain)
Post ganglionic sympathetic fibers
CN 9, 10, 12 (But only 10 extends throughout the length of the CS)
How does the course of the ICA relate to the ECA?
How about with the IJV?
Initially posterolateral then ascends medially as it courses superiorly
Lies in front and slightly medial to it.
Where is the usual level of CCA bifurcation?
C4 at the level of the thyroid cartilage
Range: C1 to T2
What is the most common persistent basilar carotid anastomosis?
The second?
- Persistent trigeminal artery
2. Persistent hypoglossal
What parts are connected by the following carotid basilar anastomoses:
- Persistent trigeminal
- Persistent otic
- Persistent hypoglossal
- Persistent proatlantal intersegmental artery
- Persistent trigeminal: Cavernous
- Persistent otic: Petrous
- Persistent hypoglossal: Cervical
- Persistent proatlantal intersegmental artery: Cervical
What hole?
How does the persistent hypoglossal artery connect with the basilar?
How does the persistent proatlantal intersegmental artery connect with the distal vertebral artery?
Through the enlarged anterior condyloid (hypoglossal) canal
Through the foramen magnum
What commonly gives rise to the occipital artery among the persistent basilar carotid anastomosis?
Persistent proatlantal intersegmental artery
Which part of the ICA is most intimately related to hearing structure ie tympanic cavity posteriorly, cochlea superiorloy and eustachian tube anteriorly?
C2
What does the vidian artery connect?
Petrous ICA to terminal ECA connection:
The proximal petrous carotid ICA (purple) to the pterygopalatine fossa (yellow) through the pterygoid canal
What is the usual angiographic origin of the vidian artery?
Usually from the IMAX but in cases such as sacrificing of the IMAX and tumors like juvenile angiofibroma the vidian artery can be seen to originate from the ICA.
The vidian artery is AKA?
Artery of the pterygoid canal
The vidian artery is a remnant of?
1st aortic arch
How does the caroticotympanic artery connect the ICA and the ECA?
C2» Caroticotympanic artery»_space; Inferior tympanic artery»_space; Ascending pharyngeal»_space; ECA
What C2 anomaly presents as a retrotympanic pulsatile mass?
What does it look like on angio?
Aberrant petrous ICA
More posterior and narrowed genu while passing through the inferior tympanic
canaliculus
The persistent stapedial artery terminates as?
Middle meningeal artery
What is the extent of C3 (Laceral segment)?
From the endocranial opening of C2 to the petrolingual ligament
What nerve crosses the laceral segment?
Greater superficial petrosal nerve– innervates the lacrimal gland
What is the only cranial nerve that course inside the cavernous sinus proper? Not merely attached to the dural sinus wall.
CN6
What does the meningohypophyseal artery (<
Pituitary gland and tentorium
Note that inconstant medial C4 branches called the capsular arteries of McConnel are found in 28% of specimens and supply the pituitary gland
How does C4 anastomose with the ECA?
C4» Lateral trunk» artery of the foramen rotundum»_space; intermal maxillary artery»_space; ECA
Which is the more lateral genu of C4?
Anterior because the horizontal part of C4 courses slightly laterally
