DEEP STRUCTURES OF THE NECK Flashcards
What are the two major layers of the cervical fascia?
The superficial cervical fascia and the deep cervical fascia
What does the superficial cervical fascia enclose and contain?
It encloses the platysma muscle and contains cutaneous nerves, superficial veins and lymph nodes.
What are the four subdivisions of the deep cervical fascia?
Investing layer of the Deep cervical fascia
Pretracheal fascia
Prevertebral fascia
Carotid Sheath
What does the Investing layer of the deep cervical fascia enclose?
The Sternocleidomastoid (anteriorly) and the trapezius (posteriorly)
What does the the pretracheal fascia enclose?
The thyroid gland, trachea and esophagus
What does the prevertebral fascia enclose?
ther vertebral column and the deep muscles of the back
Describe the carotid sheath and what is contained within the sheath
Cylinder of fascia that extends from the base of the skull to the root of the neck It contains the: Common carotid artery Internal carotid Artery Internal Jugular vein Vagus Nerve Deep cervical lymph nodes
What is the function of the fascial layers?
to provide a slippery surface to reduce friction during:
- gross movements of the head and neck
- swallowing
What is the clinical significance of the Fascial layers?
- May serve as a channel for infection
- pretracheal fascia may allow and infection to spread from the head and neck to the mediastinum directly. - Cancer involving the deep cervical lymph nodes can compress the internal jugular vein.
- Fascial layers do not stretch due to collagen fibers. First thing to get compromised is the internal jugular vein. This will create excess pressure in the brain.
What is the superior thoracic aperture (thoracic inlet)?
an opening through which structures of the neck pass into the thorax.
What are the boundaries of the superior thoracic aperture?
first thoracic vertebra
first ribs and their cartilages
manubrium of sternum
What is the shape of the superior thoracic aperture?
Kidney shaped (reniform)
What are the arteries that pass through the superior thoracic aperture?
Brachiocephalic Trunk
Left common carotid Artery
Left subclavian Artery
Internal thoracic Artery
What is the vein that pass through the superior thoracic aperture?
Brachiocephalic Vein
What are the nerves that pass through the superior thoracic aperture?
Phrenic Nerve
Vagus Nerve
Recurrent Laryngeal Nerve
Sympathetic Trunk
What are the visceral structures that pass through the superior thoracic aperture?
Trachea Esophagus Cervical Pleura Apex of Lung Thymus
Describe why there is a potential for lung collapse with Neck injury
The cervical pleura and Apex of the lung pass through the superior thoracic aperture immediately posterior to the origin of the sternocleidomastoid. A penetrating wound to the neck or a broken first rib may cause a lung collapse.
What is the clinical term for lung collapse?
Atelectasis
What organ system is the thymus a part of?
Immune system
What does the thymus produce?
T-lymphocytes
What is the blood supply to the thymus?
Internal thoracic artery
What is the nerve supply of the thymus?
stellate ganglion of the sympathetic trunk and vagus
Describe the thyroid gland
Endocrine organ which produces thyroxine and calcitonin
Lies at the level of C5-T1
H-shaped or U-shaped
What are the three parts of the thymus?
Left lobe
Right lobe
Isthmus (connects right and left lobes)
What are the anatomical variations of the thyroid?
50% of thyroid glands will have a pyramidal lobe, which extends upward from the isthmus as a finger of glandular tissue.
Another common variation is the levator glandulae thyroideae muscle, which connects the isthmus of the thyroid gland with the hyoid bone. (innervated by ansa cervicalis)
What arteries supply blood to the thyroid?
Superior thyroid artery (from external carotid artery)
Inferior thyroid artery (from thyrocervical trunk)
Thyroid ima artery: inconstant branch to the thyroid gland, from the brachicephalic trunk. Present in 10% of individuals
What veins drain blood from the thyroid?
Superior Thyroid Vein (to internal jugular vein)
Middle Thyroid Vein (to internal jugular vein)
Inferior Thyroid Vein (to brachiocephalic vein)
What is the nerve supply of the thyroid?
From the superior, middle and inferior cervical sympathetic ganglia
What is goiter?
An abnormal enlargement of the thyroid gland. Produces swelling in the neck
What is endemic goiter?
Goiter due to dietary deficiency of iodine. Iodine is necessary to produce thyroxine.
Glands enlarge to increase output. Hormone is largely inactive. Symptoms are those of hypothyroidism.
What is Exopthalamic Goiter?
Goiter due to an autoimmune disease. Thyroid stimulating immunoglobins bind to receptor sites. Causing over-activity of the gland. Hormone is active.
Symptoms are those of hyperthyroidism.
Known as Graves disease. (eyes bulge out)
