Anterior Triangle Of The Neck Flashcards
Boundaries of the anterior triangle
Anterior: Median line of the neck
Post: Anterior border of SCM
Superior: Inf border of the mandible
Apex: Jugular notch in the manubrium of the sternum
Roof: Formed by subcutaneous tissue containing the platysma
Floor: Formed by the pharynx, larynx and thyroid gland
4 subdivisions of the triangle
One unpaired submental triangle
3 small paired triangles:
1- Submandibular
2- Carotid
3- Muscular
What divides the 4 smaller triangles?
Digastric and omohyoid muscles
Location of the submental triangle
Inferior to the chin
Boundaries of the submental triangle
Apex- At the mandibular symphysis
Base- Hyoid bone
Laterally- right and left anterior bellies of the digastric muscles
Floor- two mylohyoid muscles, meeting in a medial fibrous raphe
Contents of the submental triangle
Several small submental lymph nodes
Small veins that unite to form the anterior jugular vein
Boundaries of the submandibular triangle
Superior: inferior border of the mandible
On each side: Anterior and posterior bellies of the digastric muscle
Floor: Mylohyoid and hypoglossal muscles
Contents of the submandibular triangle
Submandibular gland (mostly)
Submandibular lymph nodes (each side of the gland and along the inf border of the mandible)
Hypoglossal nerve (CN XII)
Nerve to mylohyoid muscle
Parts of the facial artery and vein
Submental artery (branch of the facial artery)
Boundaries of the carotid triangle
Superiomedial: Posterior belly of the digastric
Inferiormedial: superior belly of the omohyoid
Laterally: Anterior border of the SCM
Contents of the carotid triangle
Common carotid artery (at level of the superior border of the thyroid cartilage (C4 level), dividing into the internal and external carotid arteries)
Carotid sinus @ bifurcation (slight dilation of the proximal part of the internal carotid artery.. innervated by the glossopharyngeal nerve (CN IX)through the carotid sinus nerve..)
Carotid body (ovoid mass of tissue lying on the bifurcation of CCA close to carotid sinus)
The carotid sinus nerve is a ______ that reacts to changes in:
Baroreceptor
Arterial blood pressure
The carotid body is supplied mainly by:
It is a ______ that moniters the:
Carotid sinus nerve (CN IX)
Chemoreceptor
Level of oxygen in the blood
Boundaries of the muscular triangle
Superiolaterally: superior belly of the omohyoid muscle
Inferolaterally: Anterior border of SCM
Medially: Medial plane of the neck
Contents of the muscular triangle
Infrahyoid muscles and viscera, such as thyroid and parathyroid glands
The hyoid bone provides attachments of the _______ muscles Superior to it and the ______ muscles Inferior to it. I steadies or moves by the ____ muscles
Suprahyoid
Infrahyoid
Hyoid
Suprahyoid muscle are superior to the _____ ___ and connects it to the ______
Hyoid bone
Cranium
The suprahyoid muscles include the:
Mylohyoid, geniohyoid, stylohyoid and digastric muscles
OINA for mylohyoid
OR: Mylohyoid line of mandible
INS: Mylohyoid raphe and body of hyoid bone
NS: Nerve to Mylohyoid, a branch of inf alveolar nerve (from ma mandibular nerve, V3)
AC: elevates hyoid, floor of mouth, and tongue during swallowing and speaking
OINA for geniohyoid
OR: Inf mental spine of mandible
INS: Body of hyoid bone
NS: C1 via hypoglossal nerve (XII)
AC: pulls hyoid snterosuperiorly; shorten floor of mouth, widens pharynx
OINA for stylohyoid
OR: Styloid process of temporal bone
INS: body of hyoid bone
NS: Stylohyoid branch of facial nerve (VII)
AC: Elevates and retracts hyoid, this elongating floor of mouth
OINA for digastric
OR: anterior belly: digastric fossa of mandible
Posterior belly: Mastoid notch of temporal bone
INS: Intermediate tendon to body and greater horn of hyoid (intermediate tendon joins the 2 bellies of digastric muscle and pass through a fibrous sling which connects this tendon to the body and greater horn of hyoid bone)
NS: Anterior belly: Nerve to mylohyoid (branch of inferior alveolar nerve)
Post belly: Digastric branch of facial nerve (VII)
AC: Depresses mandible against resistance; elevates and steadies hyoid during swallowing and speaking
Infrahyoid muscles connect the hyoid to the:
Sternum, clavicle and scapula
They Depress the hyoid and larynx during swallowing and speaking
The infrahyoid muscles work with the ______ muscles to:
Suprahyoid muscles
To steady the hyoid, providing a firm base for the tongue
2 planes of the infrahyoid muscles
Superficial plane—- sternohyoid and omohyoid
Deep plane— sternothyroid and thyrohyoid
OINA for sternohyoid
OR: Manubrium of sternum and medial end of clavicle
INS: Body of hyoid bone
NS: C1-C3 by a branch of ansa cervicals
AC: Depresses hyoid after elevation during swallowing
OINA for omohyoid
OR: Superior border of scapula near Suprascapular notch
INS: Inf border of hyoid
NS: C1-C3 by a branch of ansa cervicalis
AC: Depresses retracts and steadies hyoid bone
(Two bellies united by an intermediate tendon which is connected to the clavicle by a fascial sling)
OINA for sternothyoid
lies under sternohyoid, but is wider
OR: Post. Surface of manubrium of sternum
INS: oblique line of thyroid cartilage immediately superior to the thyroid gland, so it covers the lateral lobe
NS: C2 and C3 by a branch of ansa cervicalis
AC: Depresses hyoid and elevated larynx
