Anterior Neck Flashcards
What is Fascia?
Grossly visible connective tissue or sheaths deep to the skin.
What are the different layers of fascia?
Epidermis > Dermis > Superficial Fascia > Deep Fascia
What are 2 terms synonymous with Superficial Fascia?
Subcutaneous tissue and Hypodermis
What muscle is contained within the hypodermis of the anterior neck?
Platysma m.
What nerve innervates the platysma m?
Facial n. (CN VII) - cervical br.
What movements is the platysma responsible for?
Facial expression, but mainly neck tension. It also has some role in “weak” lower lip and mandible depression.
What system is the platysma m. a part of?
the Superficial-Musculo-Aponeurotic-System (SMAS)
What are the 3 main Deep Cervical Fascia layers?
Investing Middle Deep
What is the “Investing” division of Deep Cervical Fascia responsible for?
It is the most superficial part of the Deep Cervical Fascia layers and covers the entire neck beneath the superficial fascia layers. (“deep to the skin and superficial cervical fascia”)
What are the two divisions of the Middle Deep Cervical Fascia layer?
Muscular - Covers the infrahyoid mm. and is placed more toward the front. (anterior) Visceral - Invests the majority of the organs (viscera) of the neck. (thyroid gland, trachea, esophagus)
What is the name for the subdivision of the visceral layer of the DCF?
Buccopharyngeal Fascia Surround muscles of Cheek and Pharynx
What are the 2 divisions of the Deep layer of the DCF?
Alar Fascia Prevertebral Fascia
What is the space between the Buccopharyngeal fascia and the Prevertebral Fascia?
The Retropharyngeal space
Where is the “danger space” located, and why is it referred to as such?
It is the space between the alar fascia and the preverterbral space. It is a potential space for infection to spread from the pharynx to the mediastinum (heart, trachea…).
What are the boundaries of the anterior cervical triangle?
Medial: Midline Lateral: Anterior border of the sternocleidomastoid mm. Superior: Base of the mandible
What are the 4 subdivided triangles within the anterior cervical triangle?
Submandibular triangle Submental Triangle Carotid Triangle Muscular Triangle
What are the boundaries of the Submandibular Triangle?
Inferior: Anterior and posterior of digastric m. Superior: Mandible
What is contained within the Submandibular Triangle?
the Submandibular Gland and facial a. and v.
What are the boundaries of the Submental Triangle?
Medial: Midline Lateral: Anterior belly of digastric m. Inferior: Hyoid bone
What are the boundaries of the Carotid triangle?
Superior: Posterior belly of digastric m. Lateral: Sternocleidomastoid m. Medial: Superior belly of omohyoid m.
What are the boundaries of the Muscular Triangle?
Medial: midline Inferolateral: SCM Superolateral: Superior belly of omohyoid m.
What is contained in the Carotid Triangle?
the Carotid sheath
What is contained in the Muscular Triangle?
the infrahyoid mm., the thyroid gland, and the larynx
What are the two major superficial veins of the neck?
Anterior jugular vein (AJV) External jugular vein (EJV) - Typically the most obvious superficial vein in neck
The EJV Drains into the______.
subclavian v.
How is the EJV formed?
The external jugular vein is formed when the posterior division of the retromandibular v. joins with the posterior auricular v.
How is the AJV formed?
By the junction of the superficial submandibular vv.
The AJV drains into the _________ or the __________ often after nestling under the __________.
EJV subclavian v. SCM
What characteristic does the AJV have that is not common in many veins?
it is valveless
Where is the superior attachment of the SCM?
Mastoid process and superior nuchal line (pic of mastoid process)
What is the inferior attachment of the SCM?
Sternal attachment (manubrium)
Clavicular attachment (medial third of clavicle)
What nerve innervates the SCM?
Accessory n. (CN XI)
What artery supplies the SCM?
the SCM branch of the occipital a.
What are the actions of the SCM?
it flexes the cervical vertebrae (Bilateral)
and it laterally flexes the neck and tuns the face in the opposite direction
The SCM and the trapezius mm. are both ___________ innervated by the ____________ n..
Efferently
Accessory n. (CN XI)
Where does the afferent supply come from for the SCM and Trapezius mm?
Ventral Primary Rami of cervical nerves C2-C4
Which cervical nerves afferently innervate the SCM? the Trapezius m.?
C2-C3
C3-C4
Where is the nerve point typically found on the neck?
“Erb’s point” is typically found just superior to the midpoint of the posterior margin of the SCM.
What 4 nerve points radiate from the nerve point of the neck?
Lesser occipital n. (C2-C3 area)
Great auricular n. (C2-C3 area)
Transverse cervical n. (C2-C3 area)
Supraclavicular n. (C3-C4 area)
What 2 groups can the infrahyroid mm. be classified into? What is included in each?
Superficial (sternohyoid mm. & omohyoid mm.)
Deep (sternothyroid mm. & thyrohyoid mm.)
Give the Sternohyoid’s Origen, Insertion, Innervation, and Action
Origen: Manubrium, Medial clavical, and posterior sternoclavicular ligament
Insertion: Inferior body of hyoid
Innervation: Ansa cervicalis
Action: Stabilizes hyoid; may depress an elevated hyoid.
Give the omohyoid’s Origen, Insertion, Innervation, and Action
Origen: Upper border of scapula
Insertion: Inferior body of hyoid
Innervation: Ansa cervicalis
Action: Stabilizes hyoid; may depress an elevated hyoid
What is the inferior belly of the omohyoid connected to?
The upper border of the scapula
What anchors the intermediate tendon of the omohyoid to the medial clavical?
a fascial sling
Give the Sternothyroid’s Origen, Insertion, Innervation, and Action
Origen: Manubrium
Insertion: oblique line of the thyroid cartilage
Innervation: Ansa cervicalis
Action: Pulls an elevated larynx inferiorly
Give the thyrohyoid’s Origen, Insertion, Innervation, and Action
Origen: Oblique line of thyroid cartilage
Insertion: Inferior border of hyoid bone
Innervention: C1
Action: pulls the hyoid down; elevates the larynx
What is the Ansa Cervicalis? What nerve is located proximally to it?
A nerve that innervates the Sternohyoid m., Omohyoid m., and Sternothyroid m.
The Hypoglossal n. is located proximally.
REMINDER: Nerves are collections of axons. These axons may use different nevers to get to or from their target site. This is why the fibers of the VPR are able to “hitchhike” along the hypoglossal n. before rejoining the Ansa Cervicalis
Where do the limbs of the ansa cervicalis lie within?
Within the carotid sheath
What vertebra do the thyroid glands lie between?
C5-T1
Nearly ____ of people have an accessory (pyramidal) lobe of the thyroid gland, which varies in size and typically connects the _____________________ to the ________.
50% : isthmus of the thyroid gland : hyoid bone
The Thyroid gland is what kind of gland?
Endocrine (secretes hormones - is ductless)
What hormones does the Thyroid gland secrete, and what are they responsible for?
Thyroid hormones - they are responsible for metabolism rate; and Calcintonin - important for metabolizing calcium
What arteries supply the thyroid glands?
the Superior and Inferior thyroid aa.
The ___________ is the first branch of the carotid a.
Superior thyroid a.
Name one of the branches of the superior thyroid a.
the superior laryngeal a.
The Inferior Thyroid a. is a branch of the _______________ which is a branch of the first part of the _________________.
thyrocervical trunk : subclavian a.
The thyroid glands typically drain in to 3 sets of veins. They are:
the superior thyroid vv. : the middle thyroid vv. : the inferior thyroid vv.
the superior thyroid vv. and the middle thyroid vv. drain into the _________.
internal jugular vv.
the inferior thyroid vv. drain into the _________________.
L. brachiocelphalic vv.
How many parathyroid glands are there? (typically)
4 - a superior and inferior pair (may be more or fewer)
The parathyroid glands are typically supplied by the _______________, but may be supplied by _________________.
inferior thyroid aa. : either set of thyroid aa.
The parathyroid glands are ____________ glands and produce ____________.
endocrine ; parathyroid hormone (PTH)
What structures pass through the jugular foramen?
IJV, Glossopharyngeal n. (CN IX), Vagus n. (CN X), Accessory n. (CN XI)
What is invested by the Visceral layer of the Middle DCF?
The thyroid gland, trachea, and esophagus
What is on the anterior and posterior borders of the alar fascia?
Anterior: Buccopharyngeal fascia
Posterior: Prevertebral fascia
Are cutaneous nerves afferent or efferent?
Afferent (cutaneous – skin)
What cervical branch contribute to these nerves: Lesser occipital, great auricular, transverse cervical, supraclavicular?
C2 .
C2 C3 .
C2 C3 .
C3 C4 .
What cervical nerves serve the superior root of the ansa cervicalis? Inferior root?
C1 (not both even though says on slide)
C2 C3
What innervates the thyrohyoid?
C1
What is invested by the carotid sheath?
Common and internal carotid aa.
IJV
Vagus n (CN X)
Deep cervical lymph nodes
What is the first branch of the exterior carotid artery?
Superior thyroid a.
What a. does the superior thyroid a. have as a branch?
Superior laryngeal a.
What is the recurrent laryngeal n. a branch of?
Vagus (CN X)
Is the recurrent laryngeal afferent or efferent?
Both
What divides the superior and inferior deep cervical lymph nodes?
Omohyoid
What artery does 10% of the population have laying overtop of their trachea?
Thyroid ima a.
What is an enlargement of the thyroid glands referred to as?
A goiter
