External Carotid Artery

Question 1

What to 1st and 2nd arches form?

Answer 1

1st: Stapedial arteries
2nd: Hyoid artery

Both form the hyostapedial arteries and eventually the stapedial arteries.

Question 2

The ECAs are de novo out growths from?

Answer 2

Third arches

Question 3

The hyostapedial arteries eventually become what structures

Answer 3

Main HSA trunk proximal to the stapes: Caroticotympanic artery

Maxillofacial division: + extracranial portion of the middle meningeal artery + Internal maxillary artery

Supraorbital: intracranial divison of the middle meningeal artery + orbial branches that become part of the ophthalmic artery

Question 4

At what cervical vertebral level does the ECA sprout from the CCA?

Answer 4

C4 vertebral level but can be as low as T3

Question 5

What are the precursors of the middle meningeal artery? Extracranial and intracranial portion

Answer 5

Extracranial is from the maxillofacial division of the hyostapedial arteries (&laquo_space;1st and 2nd arches)

While the intracranial portion is from the supraorbital division of the hyostapedial arteries (&laquo_space;1st and 2nd arches)

Question 6

The embryonic hyoid artery persists as the?

Answer 6

Caroticotympanic artery a branch of the petrous ICA

Important ECA-ICA bypass: It anastomoses with the tympanic branches from the ascending pharyngeal artery

Question 7

What cranial nerve is apposed to the anterior part of the ECA?

How about medial to it?

Answer 7

Cranial nerve 12

Medial: CN10 superior laryngeal nerve

Question 8

How does the ECA relate to the ICA? Initially and as it ascends the carotid sheath?

Answer 8

Initially anterior and medial then courses posterolaterally

Question 9

Enumerate all the branches of the ECA in order

Answer 9

Superior thyroid artery
Ascending pharyngeal artery 
Lingual artery
Facial artery
Occipital artery
Posterior auricular artery
Superficial temporal artery
Internal maxillary artery

Question 10

Besides the superior thyroid what else does the superior thyroid artery supply?

How does it link up with the subclavian artery circulation?

Answer 10

It supplies the larynx.

Anastomosis with the inferior thyroid artery a branch of the thyocervical trunk of the subclavian artery and sometimes with an inconstant branch of the brachiocephalic artery– arteria thyroidea ima

Question 11

Bonus

Answer 11

Bonus

Question 12

What is the first posterior branch of the ECA?

What are the other posterior branches?

Answer 12

Ascending pharyngeal artery

Occipital artery
Posterior Auricular artery

Question 13

The OccA may arise from, or have sizable direct anastomoses with, the ________ at the
Cl or C2 levels

Answer 13

Vertebral artery

Question 14

What branch of the ascending pharyngeal artery supplies the the dura and lower cranial nerves CN 7, 9, 10, 11, 12

Answer 14

Neuromeningeal branch

Question 15

Which meningeal artery arising from the internal maxillary artery has anastomoses with the ICA?

Answer 15

Accessory meningeal artery

Question 16

What foramen does the middle meningeal artery use to get inside the skull?

Answer 16

Foramen spinosum

This party looks like an abrupt 90 degree angulation on angiography.

Question 17

What are the three parts of the internal maxillary artery and its branches?

Answer 17

Proximal (mandibular): middle meningeal, accessory middle meningeal, inferior alveolar

MIddle (pterygoid): Anterior and Posterior Deep Temporal, masseteric and buccal

Distal (pterygopalatine): Superior alveolar artery, infraorbital artery (anastomosis with the ophthalmic artery), greater descending palatine artery, sphenopalatine artery (supplies nasal mucosa), artery of foramen rotundum (anastomoses with the cavernous ICA), vidian artery (anastomoses with the petrous ICA, pterygovaginal (pharyngeal) artery

Question 18

How does the distal internal maxillary artery anastomose with the ICA?

Answer 18

It also
has various anastomoses with the ICA and its branches
Some of these anastomoses
are the petrous ICA (via the vidian artery), the cavernous
ICA (via the artery of the foramen rotundum to the inferolateral
trunk), and supraclinoid ICA (ophthalmic artery
via ethmoidal branches)

Question 19

Each anatomic region is nourished by a constant terminal

vascular territory called a _____.

Answer 19

Pedicle

Question 20

The transverse facial artery is a branch of the?

Answer 20

Superficial temporal artery