Lecture 3.5 Neck muscles and fascia Flashcards
What does the superficial cervical fascia contain?
Subcutaneous tissue and platysma muscle
What does the deep cervical fascia contain?
Investing fascia, pretrachial fascia, prevertebral fascia, carotid sheath
What does the investing fascia envelop?
The entire neck
Which fascia layer envelopes the trapezius and SCM muscles?
Investing fascia. It splits to surround these muscles on all sides
Which glands are superiorly encapsulated by the investing fascia?
parotid and submandibular glands
Does the pretrachial fascia envelop muscles?
No, it continues with the buccopharyngeal fascia superiorly and descends to mediasteinum
What does the prevertebral fascia envelop?
Vertebrae and muscles
Which fascia layers contribute to the carotid sheath?
The three layers of the deep fascia: investing, pretrachial, prevertebral fascias
What muscle divides the posterior and anterior triangles of the neck?
SCM
What fascia layers and/or muscles make up the floor of the posterior triangle of the neck?
Prevertebral fascia.
Splenius capitis muscle
Levator scapulae
Scalenes (Posterior, Middle, Anterior)
Which muscles divides the posterior triangle into two triangles? What are the names of these two triangles?
Omohyoid (inferior belly).
Occipital triangle
Suprascapular
What are the three muscles of the occipital triangle borders? Suprascapular triangle borders?
SCM, Trapezius, Omohyoid.
Omohyoid, SCM, Clavicle
What structures make up the roofs of the posterior and anterior triangles?
Skin, superficial fascia with platysma muscle and deep investing fascia
What makes up the floor of the anterior triangle?
Pharynx, larynx, thyroid
What are the four subtriangles of the anterior triangle?
Submental, submandibular, carotid, muscular triangles
Which anterior triangle is singular (not paired)? What are its boundaries?
Submental triangle down the midline of the chin.
The anterior belly of the digastric muscle on each side and they hyoid bone inferiorly.
Which triangle is bounded by both bellies of the digastric muscle and the inferior border of the mandible?
Submandibular triangle
Which triangle is bounded by the SCM, superior belly of omohyoid, and the posterior border of the digastric?
Carotid triangle
Which muscles form the boundaries of the muscular triangle?
SCM, superior belly of omohyoid, and the sternohyoid
What are the suprahyoid muscles?
Anterior and Posterior bellies of digastric
Mylohyoid
Hyoglossus
Geniohyoid
Stylohoid (stradles digastric at its tendon)
What are the general actions of the suprahyoid muscles?
Lift up larynx and hyoid in swallowing and speaking
What are the general actions of the infrahyoid muscles?
Pulling down hyoid and larynx
What are the infrahyoid muscles?
Omohyoid
Sternohoid
Thyrohyoid
Sternothyroid
What are the prevertebral muscles of the neck?
Longus colli
Longus capitis
Rectus capitis anterior
Rectus capitis lateralis
Where does the platysma muscle originate? Where does it insert?
Superficial fascia of deltoid and pectoral regions.
Inferior border of mandible, some blend with risorius (a muscle of facial expression)
What is the action of the platysma muscle? Which nerve innervates it?
Stretches tight the skin of the neck, depresses mandible.
VII
Where does the SCM muscle originate? Where does it insert?
Manubrium and medial third of clavicle.
Mastoid process and lateral half of superior nuchal line
What is the action of the SCM muscle? Which nerve innervates it?
Bilaterally: Flexes neck
Individually: draws head to shoulder, turns face to opposite side.
CN XI, and C2, C3
Where does the trapezius muscle originate? Where does it insert?
Spines of all thoracic and cervical vertebrae, ligamentum nuchae, inion, superior nuchal line.
Inserts: Scapula, clavicle
What is the action of the trapezius muscle? Which nerve innervates it?
Bilateral: extends head Individually: Tilts chin to opposite side Rotates and adducts scapula Elevates scapula and clavicle XI and C3, C4
Where does the splenius capitis muscle originate? Where does it insert?
Ligamentum nuchae, lower cervical spines.
Mastoid process and superior nuchal line
What is the action of the splenius capitis muscle? Which nerve innervates it?
Bilateral: extends head
Individually: flexes head laterally, rotates head to ipsilateral side
Nerve: segmented dorsal rami of cervical nerves
Where does the levator scapulae muscle originate? Where does it insert?
Transverse processes of four upper cervical vertebrae.
Scapula
What is the action of the levator scapulae muscle? Which nerve innervates it?
Elevates and rotates scapula.
Dorsal scapular nerve
Where do the scalene muscles originate? Where do they insert?
Transverse processes of cervical vertebrae.
Posterior scalene inserts on second rib
Middle and Anterior insert on first rib
What are the actions of the scalene muscles? Which nerve innervates it?
Bilateral: flexes neck;
Individually: flexes neck laterally
Also along with SCM aid in forced inspiration by elevating the ribs and sternum
Innervation: Posterior/Anterior Scalenes - ventral root of C5 to C8
Middle scalene: ventral roots of C3, C4
Where does the inferior belly of the omohyoid muscle originate? Where does it insert?
Scapula
Intermediate tendon
Where does the superior belly of the omohyoid muscle originate? Where does it insert?
Intermediate tendon
Hyoid
What is the action of the omohyoid and sternohyoid muscles? Which nerve innervates them?
Depresses hyoid and larynx
Ansa cervicalis
Where do the sternohyoid and sternothyroid muscles originate? Where does it insert?
Manubrium
Insertion: hyoid, thyroid cartilage - respectively
What is the action of the sternothyroid muscle? Which nerve innervates them?
Depresses larynx
Ansa cervicalis
Where does the thyrohyoid muscle originate? Where does it insert?
Thyroid cartilage
Hyoid
What is the action of the thyrohyoid muscle? Which nerve innervates them?
Depresses hyoid
Thyrohyoid branch from C1 that hitchhikes on XII
Where does the posterior belly of the digastric muscle originate? Where does it insert?
Temporal bone
Intermediate tendon
Where does the inferior belly of the digastric muscle originate? Where does it insert?
Intermediate tendon
Digastric fossa of mandible
What is the action of the posterior/inferior bellies of the digastric muscle? Which nerve innervates them?
Raise and elevate hyoid
Posterior belly: VII
Anterior belly: V3
Where does the myloyoid muscle originate? Where does it insert?
Mylohyoid line of mandible
Hyoid bone
What are the actions of the mylohyoid muscle? Which nerve innervates it?
Elevate hyoid bone, base of tongue, and floor of mouth
V3
Where does the geniohyoid muscle originate? Where does it insert?
Genial tubercle of mandible
Hyoid
What are the actions of the geniohyoid muscle? Which nerve innervates it?
Elevates and protracts hyoid bone
Ventral root of C1
Where does the stylohyoid muscle originate? Where does it insert?
Styloid process
Hyoid bone
What is the action of the stylohyoid muscle? Which nerve innervates it?
Elevates hyoid
VII
Where does the longus coli muscle originate? Where does it insert?
Transverse process C3-C5.
Atlas and Bodies of T1-T3
What is the action of the longus coli muscle? Which nerve innervates it?
Flex neck and head.
C2-C8
Where does the longus capitis muscle originate? Where does it insert?
Anterior tubercles of C3-C6
Base of skull
What is the action of the longus capitis muscle? Which nerve innervates it?
Flex head
C1-C4
Where do the rectus capitis anterior/lateral muscles originate? Where do they insert?
Atlas
Occipital
What is the action of the rectus capitis anterior and lateral muscles? Which nerve innervates them?
Flex head
C1-C2
