Muscles: Neck (Dustin) Flashcards
Sternocleidomastoid
superficial neck muscle
1. Arises:
o Sternal head:
• Manubrium of the sternum
o Clavicular head:
• Medial third of the clavicle
2. Inserted:
o Mastoid process and superior nuchal line
3. Movement:
o Individually:
Marius
• Tilts head to the same side
• Rotates head to the opposite side
o Together:
• Ventral flexion of the head
4. Innervation:
o Accessory nerve (cranial nerve XI)
what is this muscle group and what is the function of their movement?
Infrahyoid muscles
Move thyroid cartilage and hyoid bone together
Pull hyoid bone and the laryngeal cartilages downward
Together with the suprahyoid muscles they bend the head forward with mouth
closed
The omohyoid muscle prevents pressure on the large underlying vein and
assists in opening the mouth and in flexion, lateral flexion and rotation of the
head
Sternohyoid
1. Arises:
o Posterior surface of the manubrium
o Sternal end of clavicle
2. Inserted:
o Inner surface of hyoid bone
3. Innervation:
o Cervical ansa of the cervical plexus
Omohyoid
Inferior belly
1. Arises:
o Superior margin of scapula, adjacent to the
scapular notch
2. Inserted:
o Intermediate tendon
3. Innervation:
o Cervical ansa of the cervical plexus
Superior belly:
1. Arises:
o Intermediate tendon
2. Inserted:
o Body of the hyoid bone
3. Innervation:
o Cervical ansa of the cervical plexus
Sternothyroid
1. Arises:
o Posterior surface of manubrium
2. Inserted:
o Thyroid cartilage
3. Innervation:
o Cervical ansa of the cervical plexus
Thyrohyoid
Is a continuation of the sternothyroid.
1. Arises:
o Thyroid cartilage
Marius
2. Inserted:
o Body of the hyoid bone
3. Innervation:
o Ventral ramus of C1
what is this muscle group?
suprahyoid muscles:
stylohyoid
mylohyoid
geniohyoid
anterior and posterior bellies of digastric
Stylohyoid
1. Arises:
o Styloid process of the temporal bone
2. Inserted:
o Body of the hyoid bone by a split tendon (split by the
digastric muscle)
3. Movement:
o Elevated the hyoid bone (during swallowing)
o Assist in opening the mandible
4. Innervation:
o Facial nerve
Mylohyoid
1. Arises:
o Mylohyoid line of the mandible
2. Inserted:
o Body of the hyoid bone by a median tendon of
insertion (mylohyoid raphe)
3. Movement:
o Tightens and elevates the oral floor
o Draws the hyoid bone forward (during
swallowing)
o Assist in opening the mandible and moving it
from side to side
4. Innervation:
o Mylohyoid nerve (from the mandibular nerve)
Geniohyoid
1. Arises:
o Mental spine
2. Inserted:
o Body of the hyoid bone
3. Movement:
o Draws the hyoid bone forward (during
swallowing)
o Assist in opening the mandible
4. Innervation:
o Ventral ramus of C1
Anterior and Posterior Bellies of Digastric Muscle
Posterior belly
1. Arises:
o Mastoid notch (medial to the mastoid process)
2. Inserted:
o Intermediate tendon, into the hyoid bone
3. Movement:
o Elevates the hyoid bone (during swallowing)
o Assist in opening the mandible
4. Innervation:
o Facial nerve
Anterior belly
1. Arises:
o Digastric fossa of the mandible
2. Inserted:
o Intermediate tendon, into the hyoid bone
3. Movement:
o Elevates the hyoid bone (during swallowing)
o Assist in opening the mandible
4. Innervation:
o Mylohyoid nerve (from the mandibular nerve)
(broad muscular area)
Platysma
The platysma is a broad, flat, subcutaneous muscular sheet.
1. Arises:
o Below the clavicle, from the pectoral fascia
2. Inserted:
o Medial fibers:
• Into the mandible
o Lateral fibers:
• Joins the muscles around the mouth
3. Movement:
o Tenses the skin
o Can move the lower lip and the corners of the mouth down
4. Innervation:
o Facial nerve
triangles of the neck: A
mandible
triangles of the neck: B
hyoid bone
triangles of the neck: C
clavicle
triangles of the neck: D
trapezius muscle
triangles of the neck: E
sternocleidomastoid
triangles of the neck: F
omohyoid muscle
runs deeper than sternocleidomastoid
triangles of the neck: G
posterior belly of digastric
triangles of the neck: H
anterior belly of digastric
triangles of the neck: 1
anterior triangle
triangles of the neck: 2
posterior triangle
contains Erb’s Point aka punctum nervosum, where 6 nerves meet. Injury to this area results in paralysis of arm muscles
triangles of the neck: 3
muscular triangle
aka inferior carotid triangle
- infrahyoid muscles
- thyroid gland
triangles of the neck: 4
submental triangle
- submental lymph nodes
- small veins
triangles of the neck: 5
occipital triangle
aka omotrapezoid triangle
- external jugular vein
- brachial plexus
- cervical plexus
- spinal accessory nerve
triangles of neck: 6
supraclavicular triangle
aka subclavian triangle or omoclavicular triangle
- subclavian artery and vein
- suprascapular artery
- usually some lymph glands
triangles of neck: 7
submandibular triangle
aka digastric triangle
- facial artery and vein
- submandibular glands
- lymph nodes
- mylohyoid nerve
triangles of neck: 8
carotid triangle
contains carotid sheath: internal jugular vein, common carotid artery, vagus nerve
- hypoglossal n
- ansa cervicalis
- accessory nerve
which fascia is in red?
superficial lamina of (or investing layer of) deep cervical fascia
surrounds the neck like a collar, it splits around the sternocleidomastoid muscles and the trapezius muscles. Posteriorly (towards the back of the neck), it blends with ligamentum nuchae.
(1 out of 3 deep cervical layers)
which fascia is in blue?
which is in purple?
what do they make together?
blue = visceral pretracheal cervical fascia
- extends medially in front of the carotid vessels, and assists in forming the carotid sheath
- fixed to the hyoid bone
- encloses the thyroid
purple = muscular pretracheal cervical fascia
together they make up the middle cervical fascia** part of the **deep cervical fascia
what is the fascia in orange?
prevertebral deep cervical fascia
-the “deep lamina” of the deep cervical fascia
Forms a tubular sheath for the vertebral column and muscles associated with it
(longus capitis, longus colli anteriorly) (scalene laterally) (deep cervical muscles
posteriorly)
Superiorly it’s fixed to the cranial base
Inferiorly it blends with the endothoracic fascia peripherally, and the anterior
longitudinal ligament centrally at Th-3 vertebra level
Laterally it extends as the axillary sheath, enclosing the axillary vessels & brachial
plexus
what is the structure in brown?
carotid sheath
borders blend with prevertebral cervical fascia and pretracheal cervical fascia
contains:
- common carotid artery*
- internal jugular vein*
- vagus nerve*
what is the layer external to the red line?
superficial cervical fascia
- not to be confused with superficial lamina of deep cervical fascia!
- lies between the dermis of the skin and the deep cervical fascia.
- contains the platysma, cutaneous nerves, blood, and lymphatic vessels.
- also contains a varying amount of fat, which is its distinguishing characteristic.
- technically not really even fascia
