Triangles of the neck Flashcards
What are the anterior and posterior triangles separated by
SCM
What are the attachments of the SCM
Sternal manubrium, sternal clavicle and mastoid process of the temporal bone (behind the ear)
What is the innervation of the SCM
Spinal accessory nerve (CN XI)
What are the borders of the anterior triangle of the neck
Superior- inferior border of the mandible
Laterally- anterior border of the SCM
Medially-sagittal line down neck midline
What are the suprahyoid muscles
Stylohyoid, digastric, mylohyoid, geniohyoid
What are the infra hyoid muscles
THyrohyoid
Omohyoid
Sternohyoid
Sternothyroid
What nerves does the anterior triangle contain
Cranial nerves
What cranial nerves does the anterior triangle contain
Facial nerve (CN VIII) Glossopharyngeal nerve (CN IX) Vagus nerve (CN X) Accessory nerve (CN XI) Hypoglossal nerve (CN XIII)
What does the carotid sheath contain
Common carotid artery Internal jugular vein Vagus nerve CNX Deep cervical lymph nodes
What does the common carotid artery bifurcate into and where
External and internal carotid artery at C4 (thyroid cartilage superior border)
What are the triangles in the anterior triangle of the neck
Bottom to top in clockwise direction on RHS:
- Muscular triangle
- Carotid triangle
- Submental triangle
- Submandibular triangle
Borders of the carotid triangle
Superior- posterior belly digastric muscle
Lateral- medial border of SCM
Inferior-Superior belly of omohyoid muscle
What does the carotid triangle contain
Carotid sheath,
Site of common carotid artery bifurcation
Vagus nerve CNX
Deep cervicxal lymph nodes
Borders of submental triangle
Inferiorly- Hyoid bone
Medially- Midline of neck
Laterally- Anterior belly of digastric
What does the submental triangle contain
Submental lymph nodes
Borders of the submandibular triangle
Superior- Body of the mandible
Anteriorly- Anterior belly of the digastric muscle
POsterior- Posterior belly of the digastric muscle
What does the submandibular triangle contain
submandibular gland and lymph nodes
Borders of the muscular triangle of the neck
Superiorly- hyoid bone
Anteriorly- midline of neck
Laterally- Superior belly of the omohyoid muscle and SCM
What does the muscular triangle of the neck contain
Infrahyoid muscles
Pharynx
Parathyroid glands
Borders of the posterior triangle of the neck
Anterior- posterior border of SCM
Posterior- Anterior border of trapezius
Inferior- middle 1/3 of clavicle
Roof- Investing layer of deep cervical fascia
Floor- Prevertebral layer of deep cervical fascia
Origin of trapezius muscle
Ligamentum niche and spinous processes of C7-T12
Insertion of trapezius
Clavicle, acromion and scapula spine
Innervation of trapezius
Spinal accessory nerve (CNXI)
Proprioceptor fibres from C3 and C4
Action of the upper fibres of trapezius muscle
elevate scapula and rotate it during arm abduction
Action of the middle fibres of the trapezius muscle
Retract scapula
Action of the lower fibres of the trapezius muscle
Pull scapula inferiorly
What are the vertebral muscles of the posterior triangle
Splenius Capitis
Levator scapulae
Anterior, middle and posterior scalenes
What is the origin of the omohyoid muscle
Inferior belly arises from scapula and runs under sternocleidomastoid.
It is attached to the superior belly by an intermediate tendon which is anchored to the clavicle by deep cervical fascia
What is the insertion of the omohyoid muscle
Superior belly attaches to hyoid bone
What is the action of the omohyoid bone
depresses the hyoid bone
What is the innervation of the omohyoid muscle
Anterior rami of C1-C3 (branch of ansa cervicalis)
