Anterior Cervical Region (Anterior Triangle) Flashcards
Boundaries of the Anterior Triangle
Anteriorly - median line of the neck (chin to jugular notch; imaginary line)
Posteriorly - by the anterior border of the SCM
Superiorly - by the inferior border of the mandible
Apex of the Anterior Triangle
jugular notch in the manubrium
Roof of the Anterior Triangle
formed by SQ tissue containing the platysma
Floor of the Anterior Triangle
Formed by the pharynx, larynx, and thyroid gland
Boundaries and Contents of the Submental Triangle
lies inferior to the chin
Laterally - by the right and left anterior bellies of digastric muscles
Contains several small submental lymph nodes and small veins that unite to form the anterior jugular vein
Floor of the Submental Triangle
formed by the 2 mylohyoid muscles
Apex of the Submental Triangle
the mandibular symphysis
Base of the Submental Triangle
formed by the body of the hyoid bone
Boundaries of the Submandibular Triangle
a glandular area
Anteriorly - by the anterior belly of digastric
Posteriorly - by the posterior belly of digastric and stylohyoid
Base - formed by the inferior border of the mandible
Floor of the Submandibular Triangle
formed by the mylohyoid, hyoglossus and middle constrictor of pharynx
Submandibular Triangle Contents
Submandibular gland, submandibular lymph nodes (lie on each side of the submandibular gland), hypoglossal nerve (12thCN), nerve to mylohyoid nerve, parts of the facial artery, facial vein, and submental artery.
Boudaries of the Carotid Triangle
Vascular area, important because the common carotid artery ascends into it.
Medially - by the superior belly of omohyoid
Laterally - by the anterior border of SCM
Superiorly - by the posterior belly of digastric
Contents of Carotid Triangle
common carotid artery, carotid sinus, carotid body and carotid sheath.
Common Carotid Artery
divides into the internal and external carotid arteries at the level of the superior border of the thyroid cartilage
Carotid Sinus
slight dilation of the proximal part of the internal carotid artery, innervated principally by the glossopharyngeal nerve (CNIX) through the carotid sinus nerve as well as by the vagus nerve (CNX)
Carotid Sinus
a baroreceptor that reacts to changes in arterior BP.
Carotid Body
small, reddish brown ovaid mass of tissue lies on the medial side of the bifurcation of the common carotid artery, close to carotid sinus. Supplied by the carotid sinus nerve, CNIX and CNX (glossopharyngeal and vagus)
Carotid Body
a chemoreceptor that monitors the level of O2 in the blood.
Carotid Sheath
tubular, fascial investment that extends from the cranial base to the root of the neck, blends anteriorly with the investing and pretracheal layers of the fascia and posteriorly with the prevertebral layer of fascia.
Contents of Carotid Sheath
common and internal carotid arteries, internal jugular vein, vagus nerve, deep cervical lymph nodes, carotid sinus nerve and sympathetic nerve fibers.
Boundaries of the Muscular Triangle
Above and Laterally - by the superior belly of omohyoid
Below and Laterally - by the anterior border of SCM
Medially - by the median plane of the neck
Contents of the Muscular Triangle
infrahyoid muscles, sternohyoid, sternothyroid, thyrohyoid, and viscera of the neck, thyroid and parathyroid glands.
Suprahyoid Muscles (4)
- Mylohyoid
- geniohyoid
- stylohyoid
- digastric (anterior and posterior bellies)
Infrahyoid Muscles (4)
superficial plane 1. sternohyoid 2. omohyoid (superior and inferior bellies) Deep plane 3. sternothyroid 4. thyrohyoid
Mylohyoid
forms the mobile and stable floor of the mouth
ORIGIN - from the mylohyoid line of the mandible
INSERTION - into the mylohyoid raphe and the body of the hyoid
NERVE - mylohyoid nerve, branch of the inferior alveolar nerve from mandibular nerve (branch of trigeminal nerve - CNV)
ACTION - to elevate the hyoid, floor of mouth and tongue during swallowing and speaking.
Geniohyoid
lies superior to mylohyoid muscle
ORIGIN - from the inferior mental spine of mandible
INSERTION - into the body of the hyoid bone
NERVE - C1 fibers via hypoglossal nerve (CNXII)
ACTION - to pull the hyoid anterosuperiorly, shortens the floor of the mouth and widens the pharynx.
Stylohyoid
runs parallel to posterior belly of digastric muscle
ORIGIN - from the styloid process of temporal bone
INSERTION - into the body of the hyoid bone
NERVE - facial nerve
ACTION - elevates and retracts the hyoid, thus elongating the floor of the mouth.
Anterior belly of Digastric
arises from the digastric fossa of the mandible
INSERTION - into the intermediate tendon to the body and greater horn of hyoid bone
NERVE - mylohyoid nerve, branch of inferior alveolar nerve from mandibular nerve (branch of trigeminal nerve - CNV)