Blood Supply and Venous Drainage of the Head and Neck Flashcards
Branches of the Subclavian Artery
- Vertebral Artery
- Thyrocervical Trunk
- Costocervical Trunk
Vertebral Artery
- Arteries from the first part of the Subclavian
- Ascends through the foramen in the processes of the Cervical Vertebrae (1-6), winds around the Atlas to enter the skull through the Foramen Magnum
- Forms the Basilar Artery by unititng with the vessel from the opposite side
- Branches in the neck supply the deep muscles and also sends branches to supply the spinal cord.
Thyrocervical Trunk
- Arises from the first part of the Subclavian and almost immediately divides into 3 branches:
- Inferior Thyroid - runs superiorly to supply the inferior aspect of the thyroid gland giving muscluar branches as well as pharyngeal and inferior laryngeal branches.
- Suprascapular - Runs behind the SCM to the superior border of the Scapula giving branches to the SCM as it passes it
-
Transverse Cervical - passes laterally in front of Scalenus Anterior and the Brachial Plexus to supply Trapezius
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Costocervical Trunk
- Arises from the second part of the subclavian
- divides into the Superior intercostal and deep cervical arteries
- Deep arteries:
- Supply the deeper muscles of the neck and anastomose with vertebral and the occipital arteries
Venous Drainage of the Neck
Deep
Veins of the head and neck are very variable ad do not have valves.
Therefore can communicate easily with other veins and thus infective thrombosis can travel extensively in this region.
Common Carotid Artery
Origin:
- left - Aortic Arch
- right - in neck from Brachiocephalic Trunk
In cervical region:
- contained in a sheath = Carotid sheath (made of deep cervical fascia)
- also in this sheath lie the internal jugular vein & vagus nerve
Bifurcates @ C4 into the Internal & External Carotid Arteries
Internal Carotid Artery
- Ascends towards the base of skull
- gives off no branches in the neck; enters the cranial cavity through the Carotid Canal in the petrous part of the Temporal bone
-
Supplies the:
- Cerebral hemispheres
- eyes
- contents of orbits
- forehead
External Carotid Artery
Mneumonic for branches:
Some Anatomists Like Freaking Out Poor Medical Students
Starts giving off branches immediately after the bifurcation of the CCA
Branches:
- Superior Thyroid Artery
- Ascending Pharyngeal Artery
- Lingual Artery
- Facial Artery
- Occipial Artery
- Posterior Auricular Artery
- Superficial Temporal Artery
- Maxillary Artery
- Superior Thyroid Artery
-
Superior Thyroid Artery:
- 1st branch
- arises from ant surface near/at bifurication
- passses down and forward to reach the superior pole of thyroid
- Facial Artery
-
Facial Artery
- 3rd ant branch; arises just above Lingual art
- passes deep to Stylohyoid & post belly of digastric muscles
- continues deep btwn Submandibular gland & mandible, emerges over edge of mandible just ant to the masseter muscle to enter the face
- Superficial Temporal Artery
-
Superficial Temporal Artery:
- 1st of the terminal branches
- upwards continuation of the ECA
- Begins post to the neck of the mandibl, passes ant to ear, crosses zygomatic process of temporal bone and above this point:
- divides into the ant & post branches
Veins: INTERNAL JUGULAR VEIN
collects blood from the skull, brain , superficial and part of neck
Begins as a dilated continuation of the SIGMOID SINUS
inital dilated part = Superior bulb of Jugular Vein
it recieves another dural venous sinus - inferior petrosal sinus
Exits skull through the Jugular Foramen and enters the Carotid sheath
Joins with the Subclavian veins posterior to the sternal end of the clavicle to form the R & L Braciocephalic veins
Tributaries of the IJV
inf petrosal sinus
facial
lingual
pharyngeal
occipital
sup thyroid
middle thyroid vein
Occipital Artery
- From post surface of ECA; near level of origin of the Facial artery
- passes upward and posterior deep to post belly of digastric muscle and emerges on post aspect of skull
Posterior Auricular Artery
- Small branch;
- from post surface of ECA & passes upwards and posteriorly
