Neck Anatomy Flashcards
What are the boundaries of the neck?
Inferiorly: Thoracic Inlet (1st thoracic vertebrae, 1st Rib and Costal Cartilage, Manubrium)
Superiorly: Inferior border of the mandible, angle of mandible, mastoid process, external occipital protuberance, superior nuchal line
What are the important anatomical features of the neck? (5)
- Hyoid Bone - C3 vertebrae
- Thyroid Cartilage - C4 upper border
- bifurcation of CCA; chemoreceptors and baroreceptors here - Cricoid Cartilage - C6
- superior end of esophagus and trachea - Trachea
- Jugular Notch
What are the boundaries of the anterior and posterior triangle of the neck?
Anterior Triangle: Midline of the Neck, Anterior Border of SCM, Inferior border of Mandible
Posterior Triangle: Posterior Border of the SCM, Middle 1/3 of Clavicle, Anterior Border of Trapezius
Tell me about the fascia of the neck.
Superficial Cervical Fascia
- Contains blood and lymphatic vessels, lymph nodes and fat, and the platysma
Deep Cervical Fascia
- Investing Fascia
- Pre-Tracheal Fascia
– Located behind the investing fascia, in front of the strap muscles, to enclose the thyroid gland
– fuses with the carotid sheath laterally
– fused with the prevertebral fascia
- Pre-vertebral fascia
– Encloses pre-vertebral muscles
– Lymph nodes of the posterior triangle are superficial to it
– Extends as the axillary sheath to enclose the axillary artery, vein and brachial plexus
Why does the thyroid gland move with swallowing?
Thyroid is attached to the cartilage of the larynx by the suspensory ligament of berry
Branches of the facial nerve?
- Frontal
- Zygomatic
- Buccal
- Marginal Mandibular
- Cervical
Muscles of Neck
1
Where is the carotid sheath located in the neck?
Posterior to the SCM; anteromedially to the anterior scalene
What are the contents of the carotid sheath?
Common Carotid Artery and its bifurcation; Internal Jugular Vein and Vagus Nerve
What are the branches of the external carotid artery?
Some Attendings Like Freaking Out Potential Medical Students
Superior Thyroid Artery
Ascending Pharyngeal Artery
Lingual Artery
Facial Artery
Occipital Artery
Posterior Auricular Artery
Maxillary Artery
Superficial Temporal Artery
Name the anastomoses and collateral circulation relating to the thyroid
Left and Right Superficial Temporal Arteries
Left and Right Superior Thyroid Arteries
Left and Right Inferior Thyroid Arteries
Left and Right Facial Arteries
Superior and Inferior Thyroid Arteries
Describe the vein flow in the neck
Posterior Auricular Vein and Superficial Temporal Vein unite to form External Jugular Vein
Superficial Temporal Vein also has a branch to unite with the facial vein that unites to become the common facial vein. Facial vein drains into the internal jugular vein
EJV and IJV drain into subclavian vein then into the brachiocephalic vein to SVC
Surface mark the EJV
Angle of Mandible to Midpoint of Clavicle
What are the branches of the subclavian artery?
Part 1:
- Vertebral
- Thyrocervical Trunk –> Inferior Thyroid
- IMA
What are the contents of the anterior triangle and posterior triangle of the neck?
What is the main nervous plexus of the neck. Tell me about it.
Cervical Plexus.
‘Motor Branches’
- Phrenic Nerve (C3-C5): Anterior to Ant scalene, to enter thorax, descends anterior to root of the lung to reach the diaphragm
- C1 nerves that innervate the thyrohyoid and geniohyoid flowing within the hypoglossal
- Ansa Cervicalis
- Minor Branches (C3-C4: Levator Scapulae, Trapezius and Middle Scalene)
‘Sensory’ Branches - Let’s Go To Sleep
- Lesser Occipital
- Greater Auricular
- Transverse Cervical
- Supraclavicular
What is the course of spinal accessory nerve?
C1-C6 nerev roots coalese, run superiorly to enter the cranial cavity via foramen magnum
Traverses posterior cranial fossa to reach the jugular foramen, exits skull with CN9 and CN10
Descrnds along the ICA to reach SCM, moves across the posterior triangle of the neck to the trapezius
Tell me about the sympathetic trunk in the neck
Three cervical ganglia
- Superior (C2-C3): Sympathetic innervation mostly from here
- Middle (C6)
- Inferior (First rib behind vertebral artery)
Embedded on the posterior wall of the carotid sheath
Where is the location of the thyroid gland
C5 to T1, below cricoid cartilage
What is the blood supply of the thyroid gland?
Superior Thyroid Artery (ECA)
Inferior Thyroid Artery (Subclavian –> Thyrocervical Trunk –> IFA)
What is the importance of the cricothyroid muscle. What is its nerve supply?
Tenses the vocal cord for screaming. Supplied by the External Laryngeal Nerve
Tell me about the nerve supply around the thyroid gland?
Vagus nerve runs in carotid sheath. On left side, gives off a recurrent laryngeal branch that curves under arch of aorta . On right side, gives off recurrent laryngeal branch that curves under subclavian artery. These are in close proximity to the Inferior Thyroid Artery. Eventually the nerve lies just deep to the isthmus.
Vagus nerve also gives off the superior laryngeal nerve which branches into the internal and extenal laryngeal branches. External is in close proximity to the superior thyroid artery. Internal pierces the thyrohyoid membrane
