Great vessels of the neck External carotid artery (dave's notes)

Question 1

Where does the external carotid artery initiate? What its course thereafter relative to the internal carotid?

Answer 1

Bifurcation is at C4. Here the external carotid slopes upwards, initially medial and then anterior to the internal carotid artery.

Question 2

What does the external carotid artery pass deep to?

Answer 2

The posterior belly of digastric and stylohyoid

Question 3

What does the external carotid artery pierce and when?

Answer 3

After passing deep to the posterior belly of digastric and stylohyoid, the ECA pierces the deep lamina of the parotid where it further divides.

Question 4

What separates the ECA and ICA within the parotid gland?

Answer 4

The deep part of the gland and the pharyngeal structures (stylopharyngeus, glossopharyngeal, and the pharyngeal branch of the vagus)

Question 5

List the pharyngeal structures and one possible variant

Answer 5

Stylopharyngeus, glossopharyngeal, and the pharyngeal branch of the vagus, +/- branchial fistula

Question 6

What are the surface markings relevant to the external carotid artery?

Answer 6

From the greater horn of the hyoid to just in front of the tragus

Question 7

Summarise the locations of the branches of the external carotid

Answer 7

8 branches:
3 in front (of what?)
2 behind
1 deep before the parotid
2 terminal within the gland

Question 8

Give a mnemonic for the branches of the external carotid

Answer 8

Aunt Sally Likes Fat Politicians On Soft Mattresses

Question 9

List the branches of the external carotid artery, and the position of the branches relative to the ECA

Answer 9

Ascending pharyngeal (deep)
Superior thyroid artery (anterior)
Lingual artery (anterior)
Facial artery (anterior)
Posterior auricular artery (anterior)
Occipital artery (posterior)
Superficial temporal artery (terminal)
Maxillary artery (terminal)

Question 10

Describe the course of the ascending pharyngeal artery. What branches does it give off? Through which foramen do these branches pass?

Answer 10

The ascending pharyngeal artery runs up on the side wall of the pharynx deep to the internal carotid, supplying pharyngeal walls and the soft palate.
It sends meningeal branches through the foramen lace rum, jugular foramen, and hypoglossal canal.

Question 11

Describe the course and branches of the superior thyroid artery

Answer 11

From its commencement slopes vertically downwards to the upper pole of the thyroid. Runs with the external laryngeal nerve. Its main branch is the superior laryngeal artery

Question 12

Give the course of the lingual artery

Answer 12

Runs upwards and then forwards along the upper border of the hyoid, deep to hyoglossus

Question 13

Give the course and branches of the facial artery

Answer 13

Runs upward on the superior constrictor muscle, deep to digastric, stylohyoid and the submandibular gland, indenting this. Gives off a tonsillar branch (to tonsil and soft palate). Later supplies the mandible, then gives of a submental artery to the anterior belly of digastric and myelohyoid - not the only supply to these muscles

Question 14

Give the course and branches of the posterior auricular artery. What does it supply?

Answer 14

Arises at the level of the digastric, sometimes within the parotid gland, and runs up superficial to the styloid process across the upper border of digastric. Supplies the skin over the mastoid process. Gives off a stylomastoid branch which enters the stylomastoid foramen, supplies the facial nerve and gives of the stapedial artery

Question 15

What is the stapedial artery a branch of? What is it a remnant of?

Answer 15

The posterior auricular artery. Remnant from the 2nd pharyngeal artery.

Question 16

Give the course and branches of the occipital artery. What does it supply?

Answer 16

Arises on a level with the fascial artery, passes on the lower border of the belly of digastric. Gives two branches to SCM - the upper of which is a guide to the accessory nerve. The origin of the artery is hooked by the hypoglossal nerve. Supplies the back of the scalp.

Question 17

What two nerves of import are associated with the occipital artery and how?

Answer 17

The hypoglossal nerve hooks the origin of the occipital artery from the external carotid. The upper of two branches of the occipital artery to SCM is a landmark for the accessory nerve.

Question 18

What are the two terminal branches of the external carotid?

Answer 18

Superficial temporal artery and maxillary artery