Anatomy of the Head and Neck

  • Course Information
  • Vasculature and Lymphatics
  • Innervation
  • Muscles
    • Muscles of the Neck
      30 min
  • Regions and Spaces of the Head
    • Infratemporal Fossa
      30 min
  • Nasal Cavity & Paranasal Air Sinuses
  • Oral Region
  • Pharynx and Esophagus
  • Layers, Regions and Triangles of the Neck
    • Muscles of the Neck
      30 min
  • Larynx, Trachea, and Thyroid Gland
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Blood Supply

The blood supply of the head and neck consists of two contributors:

  1. The carotid system
  2. Branches of the subclavian artery

The carotid system

Generally, the carotid system supplies the upper neck and head (including most of the brain). It consists of the internal and external carotid arteries:

  • The carotid system of each side begins as the common carotid artery (CCA)
    • The left CCA branches out of the arch of the aorta
    • The right CCA branches out of the brachiocephalic trunk
    • Thus, the two CCAs are of different length — the right one is 1cm shorter
  • Both sides have a similar course from the neck upwards
  • The CCA branches out to the internal (ICA) and external carotid artery (ECA) approximately at the level of the 4th cervical vertebra (C4) or at the superior edge of the thyroid cartilage
  • The external carotid artery is the main contributor to the blood supply of the head and upper neck, while the internal carotid artery supplies only small parts of it (its main blood supply is the brain)

 

Aortic arch and related structures (Credit: OpenStax, CC BY-SA 4.0)

Subclavian artery

The subclavian artery supplies the upper limbs, neck, spinal cord, and the posterior cranium.

Origin and path

  • The right subclavian artery arises from the brachiocephalic trunk
  • The left subclavian artery arises from the arch of the aorta directly
  • As the subclavian arteries progress towards the limbs and pass the first rib, they become the axillary artery

Parts of the subclavian artery

The anterior scalene muscle divides the subclavian artery into three parts — medial, posterior and lateral parts (shown in the illustration below).

Medial part
  1. Vertebral artery
    • Enters the transverse foramen of the cervical vertebrae of C6, leaving on a groove on C1 vertebra
    • Supplies the spinal cord and the brain
  2. Thyrocervical trunk
    • Called trunk because the vessel is very short since it splits into several branches right away
    • Gives off 4 branches:
      • Suprascapular artery
      • Transverse cervical artery
      • Inferior thyroid artery
        • Will give off the inferior laryngeal artery
        • Inferior thyroid and inferior laryngeal arteries supply the lower larynx, trachea and thyroid gland
      • Ascending cervical artery
  3. Internal thoracic artery
    • Descends to supply the thoracic wall and chest
Posterior part

Contains the costocervical trunk which branches out to:

  • Superior or supreme intercostal artery
  • Deep cervical artery
Lateral part

In some cases, the dorsal scapular artery will arise directly from the subclavian artery at this part, opposed to from the transverse cervical artery of the thyrocervical trunk.

Subclavian artery and its branches

Clinical correlation

Pulse palpation

In the head and neck, we can palpate the pulse and measure the heart rate in several locations:

  • Temporal pulse — Can be palpated at two places:
    1. Directly from the superficial temporal artery, can be felt on the surface between the external acoustic meatus and the zygomatic bone
    2. Anterior branch of the superficial temporal artery can be felt on the surface around the pterion
  • Facial pulse
    • Can be palpated at the angle of the mandible
  • Carotid pulse
    • Can be palpated at the medial border of the sternocleidomastoid muscle, lateral to the thyroid cartilage (at the level of C4-C5 vertebra)

The pulse should be palpated using 2-3 fingers (without the thumb) by pressing moderately on the bony region.

Pulse palpation sites (Credit: OpenStax, CC BY-SA 4.0)

References

1. Moore, Keith L., et al. Clinically Oriented Anatomy. Wolters Kluwer, 2018.
2. Standring, Susan, and Henry Gray. Gray’s Anatomy: The Anatomical Basis of Clinical Practice. Elsevier, 2016.
3. Bertalan, Csillik, et al. Regional Anatomy. Medicina, 2008.

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