Download Anatomy Lecture 5 – Root of the Neck

Anatomy Lecture 5: Root of the Neck
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Thoracic Outlet Syndrome:
o Physical trauma that can cause interference with the blood and nerves
to the extremities
o Symptoms:
 Neurological: caused by compression of the brachial plexus
 Pain in the shoulder and neck, wasting of muscles at the
base of the thumb, numbness, tingling in fingers
 Vascular: caused by compression of arteries and veins
 Arm pain and swelling, paleness or blue tint, weak
pulse, blood clots in hand or shoulder
o Known Causes:
 Scalene Syndrome: spasm or scarring of Scalene Muscles
compress the subclavian or Brachial Plexus. Results in
ischemia and limb pain.
 Costoclavicular Syndrome: compression of the Subclavian
between the Clavicle and the first rib. Results in pallor and
coldness of the upper limb.
 Cervical Rib Syndrome: Congenital rib from the C7 vertebra
results in compression of the brachial plexus between the rib
and the scalene muscles. Results in weakness affecting the
base of the thumb
Thyroid Gland
o Normally two lobs connected by an isthmus which extend around the
trachea
o Pyramidal Lobe: sometimes present thyroid tissue can develop along
the embryonic path of the duct
o Secretes thyroxin to regulate metabolism
o Arterties and Veins:
 Superior Thyroid Artery: From External Carotid
 Inferior Thyroid Arteries: From Thyrocervical Trunk
 Thyroid IMA Artery: Unpaired, from Brachiocephalic Trunk or
Aortic Arch
 Middle Thyroid Vein – Unpaired
o Pathology:
 Thyroglossal Cysts: originates from the tongue and migrates
down the Thyroglossal Duct
 Causes Goiter (swelling due to Iodine deficiency,
heredity)
 Graves Disease (Hyperthyroidism)
 Autoimmune disease in which antibodies activate
growth.
Parathyroid Glands:
o 4, 6, or even 8 located on the posterior surface of the Thyroid Gland
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o Maintains calcium levels for the body
o Damage can cause death. You need Parathyroid Hormone, Calcium,
and Vitamin D.
o Must be moved during thyroid surgery
 ** Must also watch for damage to the Recurrent/Inferior
Laryngeal Nerve of the Vagus.
Fascia of the Neck:
o Investing Fascia:
 Attached to ligamentum nuchae, mandible, and mastoid
process, acromion, clavicle, and manubrium (most superficial)
 Splits to ensheath trapezius, omohyoid, sternocleidomastoid,
parotid, and submandibular glands
o Pretracheal Layer
 Limited to anterior part of the neck.
 Attaches to cricoid cartilage, fuses with fibrous pericardium,
and surrounds the thyroid gland along with infrahyoid
muscles.
o Prevertebral Layer:
 Encircles the vertebral column and associated muscles from
the base of the skull to thoracic vertebra 3.
 Invests the scalene muscles
 Covers the floor of the posterior triangle
 Splits into two layers:
 Deep layers onto the cervical vertebra
 Superficial (alar) layer
 The compartment between the Pre-Vertebral Fascia and
the Alar Fascia is called the DANGER SPACE
o The Carotid Sheath
 Contains the Internal Jugular Vein, the Common Carotid Artery,
and the Vagus Nerve
o Retropharyngeal Space: Between Buccalpharyngeal Fascia (posterior
to pretracheal space) and the Alar Fascia (anterior to the Prevertebral
Fascia)