Neck region Flashcards
Borders of Carotid triangle
Sup: posterior belly og digastric
Medial: superiod belly of omohyoid
Lat: Sternocleido mastoid muscle
Content on carotid triangle
-Carotid sheath with:
-Internal jugular vein
-Common carotid a (bifurcates within triangle)+
carotid sinus with baroreceptors.
-Vagus n
-spinal accessory n
-Ansa cervicalis (sup. root)
-Deep cervical lymph nodes
-Hypoglossal n
(-Pharynx and larynx?)
(intermediate belly of omohyoid m. has extra insertion on carotid sheath to prevent collapsing of IJV during respiration.)
Borders of Submental triangle
Inferiorly – hyoid bone.
Medially – midline of the neck.
Laterally – anterior belly of the digastric
Base – Mylohyoid muscle
Content of submental triangle
- Submental lymp nodes
- Small vein which unite to form Anterior jugular vein.
Borders of Submandibular triangle
Superiorly – body of the mandible.
Anteriorly – (or medially?) anterior belly of the digastric m.
Posteriorly – posterior belly of the digastric muscle.
(but stylohyoid m is right there as well!)
Content of Submandibular triangle
-Submandibular gland
-Submandibular lymph nodes
-Fascial a & v pass through in triangle
(-Mylohyoid n
-Hypoglossal n)
Situation and borders of Muscular (Omotracheal) triangle
It is situated more inferiorly than the subdivisions and its a slightly ‘dubious’ triangle, in reality having four boundaries. Superiorly – hyoid bone.
Medially – imaginary midline of the neck.
Supero-laterally – superior belly of the omohyoid muscle.
Infero-laterally – inferior portion of the
sternocleidomastoid muscle
Content of Muscular (Omotracheal) triangle
-The Infrahyoid muscles:
-Sternohyoid
-Sternothyroid
-Thyrohyoid
(-The Pharynx)
-The thyroid,
-Parathyroid glands. (thyroid gland?)
how is the Posterior triangle of the neck divided?
The omohyoid muscle splits the posterior triangle of the neck into two:
1) The larger, superior part is termed the occipital triangle.
2) The inferior triangle is known as the subclavian triangle and contains the distal portion of the subclavian artery.
Which triangles are sub divisions of the anterior triangle of the neck?
- Submandibular triangle
- Submental triangle
- Carotid triangle
- Muscular triangle
Border of Occipital triangle
-SCM
-Inferior belly of omohyoid m.
(and clavicle?)
Floor; -A number of vertebral muscles (covered by prevertebral fascia) form the floor of the posterior triangle:
Splenius capitis
Levator scapulae
Anterior, middle and posterior scalenes
Content of occipital triangle
-External jugular vein =>Within the posterior triangle, the
EJV pierces the investing layer of fascia and
empties into the subclavian vein.
-Tranverse cervical a
-spinal accessory n
-Trunks of brachial nerve plexus
-Poterior branchess of cervical nerve plexus
-Tranverse cervical chain of lymphnodes
Borders and content of Scalene triangle
Anterior: - Ant. Scalene => Phrenic n runs on ant border on
ant. scalene right outside triangle
Post: -Middle Scalene => long thoracic nerve (pierces?)
Middle scalene muscle
Inferior: -First rib => subclavian vein
Content: -Subclavian a
- Brachial plexus (cords)
Borders of Supraclavicular/Subclavian/Omoclavicular triangle
- Medial: Clavicular head of SCM
- Lateral: Inferior belly of OH m.
- Inferior: Clavicle
Content of Supraclavicular/Subclavian/Omoclavicular triangle
- Subclavian artery (and sometime vein)
-Suprascapular artery
-Suprascapular lymph nodes (may recieve metastais of
Gastric cc)
What make up the EJV?
Formed by the retromandibular and posterior auricular veins.
Suprahyoid muscles
A group of four muscles, located superiorly to the hyoid bone of the neck. which elevate the hyoid bone => involved in swollowing.
- Mylohyoid
- Stylohyoid
- Geniohyoid
- Digastric
-Arterial supply to these muscles is via branches of the facial artery, occipital artery and lingual artery
Superior root of deep ansa cervicalis
The superior root of the ansa cervicalis is formed from cervical spinal nerve 1 of the cervical plexus. These nerve fibers travel in the hypoglossal nerve before separating in the carotid triangle to form the superior root. The superior root goes around the occipital artery and then descends on the carotid sheath.
It sends off branches to the superior belly of the OH muscle, and the upper parts of the sternothyroid and sternohyoid muscles and is then joined by the inferior root.
inferior root of deep Ansa cervicalis
c2,c3:
gives branches to:
-
Origin and innervation of Digastric:
Ant belly: originates from digastric fossa of mandible, inserts on common tendon of digastric
- derived from 1st pharyngeal arch) => innervated by Mylohyoid n, branch of mandibular nerve (CN V)
- pulls mandible forward and depresses it.
intermediate tendon: on minor cornu of hyoid bone.
Post. belly: Mastoid notch of temporal bone —->
intermediate tendon of digastric.
-Derived from 2nd pharyngeal arch=> innervated by
facial nerve
-Draws back hyoid bone.
name the Suprahyoid muscles
-digastric
-stylohyoid
-geniohyoid,
-mylohyoid
they’re all pharyngeal muscles except for geniohyoid.
Stylohyoid muscle
O: post. styloid process of temporal bone
I: body of hyoid bone ==> its splits/goes around the beginning of post. belly of digasstric.
Action: -elevates and retracts hyoid bone
- assists in lowering mandible
Innervation: facial n.
Mylohyoid:
forms the floor or oral cavity
O: the mylohyoid line of the mandible
I: hyoid bone.
Actions: Elevates the hyoid bone and the floor of the
mouth.
Innervation: Inferior alveolar nerve, a branch of the
mandibular nerve (which is derived from the
trigeminal nerve)
Innervation infrahyoid muscles
all innervated by deep ansa but the Thyrohyoid muscle which is innervated by superficial ansa (C1 traveling with Hypoglossal until carotid triangle)
