Borders of Anterior Triangle
Anterior border: Midline of the neck
Superior border: inferior border of the mandible
Posterior border: SCM
What separates the anterior triangle from the posterior triangle?
SCM...
SCM is posterior border of anterior triangle and anterior border of posterior triangle
Hyoid...
shape, location and function
Shape: U shaped, made of greater horn, lesser horn and body
Location: inferior to the mandible at C3
Function: provides site of attachment of many facial muscles... less horn is attachment sight of stylohyoid ligament
Thyroid cartilage...
location
C4 and C5
Cricoid cartilage...
location
C6
C6 also serves as the end of the pharynx and beginning of the esophagus
What are the 4 smaller triangles of the anterior triangle?
Submental triangle
Submandibular triangle
Muscular triangle
Carotid triangle
Submental triangle borders
UNPAIRED
Superior border: anterior belly of digastricmuscle
Inferior border: hyoid bone
Submandibular triangle borders
Superior border: inferior border of mandible
Anterior border: anterior belly of digastric muslce
Posterior border: posterior belly of digastric muscle
Muscular triangle borders
Midline of neck
SCM
Superior belly of omohyoid muscle
Carotid triangle borders
Posterior belly of digastric muscle
Superior belly of omohyoid muscle
SCM
Roof of anterior triangle
Platysma
Deep cervical fascia
Floor of submandibular triangle
Mylohyoid muscle
Hyoglossus muscle (deeper)
What 4 muscles make up the suprahyoid muscles?
Anterior belly of digastric
Posterior belly of digastric
Stylohyoid
Mylohyoid
Origin of Anterior belly of digastric
Digastric fossa of mandible
Insertion of Anterior belly of digastric
Via intermediate tendon to body and greater horn of hyoid
Origin of posterior belly of digastric
Mastoid notch (temporal bone)
Insertion of posterior belly of digastric
Via intermediate tendon to body and greater horn of hyoid
Origin of stylohyoid
Styloid process (temporal bone)
Insertion of stylohyoid
Body of hyoid
Origin of Mylohyoid
Mylohyoid line of mandible (inside mandible)
Insertion of Mylohyoid
Mylohyoid (median) raphe and body of hyoid
Raphe
Where two muscles interact with each other and join
Origin of geniohyoid
inferior mental spine (lower anterior area)
Insertion of geniohyoid
body of hyoid
What is the function of the surpahyoid muscles?
Swallowing reflex to elevate the tongue and floor of the mouth
Also help open the jaw when the hyoid is held down by the infrahyoid muscles
What innervates anterior belly of digastric and mylohyoid?
Nerve to the mylohyoid CN V V3 branch, remember that these muscles are derived from pharyngeal arc 1 which makes them SVE (special visceral efferent) fibers
What innervates the posterior belly of digastric and stylohyoid?
CN VII, remember that these muscles are derived from pharyngeal arc 2 which makes them SVE (special visceral efferent) fibers
What are the 3 branches of the trigeminal nerve?
Opthalmic
Maxillary
Mandibular
Contents of submandibular triangle
Superficial part of the submandibular gland
Submandibular lymph nodes
Function of submandibular lymph nodes?
Drain the upper lip, lateral part of the lower lip, margin of the tongue and posterior teeth
What separates the superficial and deep parts of the submandibular gland?
Mylohyoid muscle
What nerve is in danger when surgery is done in the submandibular triangle?
CN VII (facial) because 20% of the time the marginal mandiblular branch is below the inferior border of the mandible
Contents of submental triangle?
Mylohyoid mm
Submental lymph nodes
Function of submental triangle?
Drain tip of tongue, mandibular anterior teeth, and median part of lower lip
Where would a carcinoma in center of lower lip drain to?
Submental lymph nodes
Where would a carcinoma in center of upper lip drain to?
Submandibular lymph nodes
What 4 muscles make up the infrahyoid mm?
Sternohyoid
Omohyoid
Sternothyroid
Thyrohyoid
What 2 infrahyoid muscles are more superficial, and what 2 muscles are deep
Superficial: Sternohyoid and omohyoid
Deep: Sternothyroid and Thyrohyoid
Function of mm
Fix and steady the hyoid bone, movements of the tongue and swallowing
Ansa Cervicalis...
Location
Closely related to carotid sheath superficial to internal carotid aa but deep to omohyoid m
Ansa Cervicalis...
Function and composition
Function: Innervates the strap muscles, which are GSE fibers (bc cervical myotomes)
Composition: Superior root (C1) and inferior root (C2 and C3) are joined by this loop
What cervical segments make up the cervical plexus?
C1-C4
Where does the carotid artery split? and which one of the split arteries branches?
Carotid artery splits at CV4 into the internal carotid artery (ICA) which distributes to inside of skull and external carotid artery (ECA) which branches and distributes to the outside of the skull
What is the pnemonic for external carotid artery names?
SALFOPSM
Name the 8 branches of the external carotid artery
Superior thyroid a
Ascending pharyngeal a
Lingual a
Facial a
Occipital a
Posterior auricular a
Superficial temporal a
Maxillary a