Triangles Of The Neck And Content Flashcards
What are the four compartments of the neck?
Vertebral
Visceral
Two vascular compartments
What are the two main triangles of the neck, and what muscle divides them?
Anterior triangle
Posterior triangle
They are divided by the sternocleidomastoid muscle (SCM).
What are the boundaries of the posterior triangle of the neck?
Anterior: Sternocleidomastoid (SCM)
Posterior: Trapezius
Inferior: Middle third of the clavicle
Apex: Superior nuchal line
Roof: Investing layer of deep cervical fascia
What are the subdivisions of the posterior triangle?
Occipital triangle
Supraclavicular (omoclavicular) triangle
What are the contents of the posterior triangle?
External jugular vein
Posterior branches of the cervical plexus
Spinal accessory nerve (CN XI)
Brachial plexus trunks
Cervicodorsal artery and vein
Cervical lymph nodes
Subclavian artery (3rd part)
Subclavian vein (sometimes)
What are the boundaries of the anterior triangle of the neck?
Posterior: Sternocleidomastoid (SCM)
Anterior: Median line of the neck
Superior (Base): Inferior border of the mandible
Roof: Subcutaneous fascia and platysma
Floor: Pharynx, larynx, and thyroid
What are the subdivisions of the anterior triangle?
Submental triangle
Submandibular (digastric) triangle
Muscular triangle
Carotid triangle
What are the contents of the submental triangle?
Submental lymph nodes
Anterior jugular vein
What are the contents of the submandibular triangle?
Submandibular salivary gland
Submandibular lymph nodes
Facial artery and vein
Hypoglossal nerve (CN XII)
Nerve to mylohyoid (V3)
What are the contents of the carotid triangle?
Upper end of the common carotid artery
Proximal part of the internal carotid artery
External carotid artery and its branches
Carotid sinus (CN IX, X)
Carotid body (CN IX, X)
Hypoglossal nerve (CN XII)
Ansa cervicalis
External and internal laryngeal nerves
What are the boundaries of the muscular triangle?
Midline: Midline of the neck
Superior: Superior belly of the omohyoid
Anterior: Anterior border of the sternocleidomastoid
What are the contents of the muscular triangle?
Sternohyoid muscle
Sternothyroid muscle
Suprahyoid and infrahyoid muscles
What are the branches of the external carotid artery?
Superior thyroid artery
Ascending pharyngeal artery
Lingual artery
Facial artery
Occipital artery
Posterior auricular artery
Superficial temporal artery
Maxillary artery
What is the thyroid gland, and where is it located?
The thyroid gland is an unpaired endocrine gland located low in the front of the neck. It consists of two symmetrical lateral lobes connected by an isthmus. It extends from the oblique line of the thyroid cartilage to the 6th tracheal ring and weighs about 25 grams.
What are the blood supply and venous drainage of the thyroid gland?
Arterial supply:
Superior thyroid artery (branch of external carotid)
Inferior thyroid artery (branch of thyrocervical trunk)
Thyroid ima artery (3% of cases, from brachiocephalic trunk or aortic arch)
Venous drainage:
Superior, middle, and inferior thyroid veins
What are the parathyroid glands, and where are they located?
The parathyroid glands are two pairs of small endocrine glands located on the deep surface of the lateral lobes of the thyroid gland. They are derived from the 3rd (inferior) and 4th (superior) pharyngeal pouches.
What is the carotid sinus, and what is its function?
The carotid sinus is a dilated area at the bifurcation of the common carotid artery. It contains baroreceptors that monitor blood pressure and is innervated by CN IX (glossopharyngeal) and CN X (vagus).
What is the carotid body, and what is its function?
The carotid body is a small cluster of chemoreceptors located near the bifurcation of the common carotid artery. It detects changes in blood oxygen, carbon dioxide, and pH levels and is innervated by CN IX and CN X.
What is the internal jugular vein, and what are its tributaries?
Inferior petrosal sinus
Facial vein
Lingual vein
Pharyngeal vein
Occipital vein
Superior and middle thyroid veins
What are the cranial nerves associated with the neck, and what are their functions?
Facial nerve (CN VII): Motor to facial muscles, taste to anterior 2/3 of tongue
Glossopharyngeal nerve (CN IX): Taste to posterior 1/3 of tongue, innervation of carotid sinus and body
Vagus nerve (CN X): Parasympathetic innervation, laryngeal muscles
Accessory nerve (CN XI): Motor to sternocleidomastoid and trapezius
Hypoglossal nerve (CN XII): Motor to tongue muscles
What is the thyroglossal duct, and what clinical conditions are associated with it?
Thyroglossal cysts: Midline neck swellings due to remnants of the duct.
Thyroglossal fistulas: Abnormal connections between the cyst and the skin.
What are the key considerations during thyroid surgery regarding nerves and arteries?
The superior thyroid artery is closely related to the external laryngeal nerve (damage can affect voice pitch).
The inferior thyroid artery is closely related to the recurrent laryngeal nerve (RLN) (damage can cause hoarseness or vocal cord paralysis).
What structures are contained within the carotid sheath?
Common carotid artery
Internal jugular vein
Vagus nerve (CN X)
What are the branches of the cervical plexus, and what do they innervate?
Lesser occipital nerve: Posterior scalp.
Great auricular nerve: Ear and parotid region.
Transverse cervical nerve: Anterior neck.
Supraclavicular nerves: Shoulder and upper chest.
What are the suprahyoid and infrahyoid muscles, and what are their functions?
Suprahyoid muscles (e.g., stylohyoid, mylohyoid, digastric, geniohyoid): Elevate the hyoid bone during swallowing.
Infrahyoid muscles (e.g., omohyoid, sternohyoid, thyrohyoid, sternothyroid): Depress the hyoid bone and larynx during swallowing and speech.
What is the pyramidal lobe of the thyroid gland?
The pyramidal lobe is a common variation of the thyroid gland, representing a remnant of the thyroglossal duct. It extends upward from the isthmus of the thyroid gland.
What is the ansa cervicalis, and what does it innervate?
The ansa cervicalis is a loop of nerves in the carotid triangle formed by branches of the cervical plexus. It supplies the infrahyoid muscles.
What is the prevertebral fascia, and where is it located?
The prevertebral fascia covers the deep muscles of the neck (e.g., scalenes, longus colli) and forms the floor of the posterior triangle.
