Back and Neck Muscles Flashcards
What are the attachments of sternocleidomastoid (SCM)?
- S: mastoid process
- I: sternum (sternal head)
- I: clavicle (clavicular head)
What are the actions of sternocleidomastoid?
- contralateral rotation of the head and neck
- ipsilateral lateral flexion of the head and neck
- flexion of the neck (if the head/neck is in neutral or flexed)
- extension of the head (if the head is already extended)
- assists with inspiration
- anterior translation of head on neck
What are the borders and contents of the Anterior Cervical Triangle
- base: mandible
- lateral border: SCM
- medial border: midsagittal plane of the neck
- contents: muscles, arteries, veins, lymph nodes, viscera, thyroid and parathyroid glands
What are the borders, floor and contents of the Posterior Cervical Triangle?
- base: clavicle
- anterior: SCM (posterior aspect)
- posterior border: trapezius
- floor:
- splenius capitis
- levator scapula
- middle scalenes
- posterior scalenes
- omohyoid
- brachial plexus
- subclavian artery and vein
- contents: blood vessels and nerves
Where is the larynx located and what does it do?
- location: just inferior to where the pharynx splits into the trachea and the esophagus
- does voice production (Adam’s apple is formed by the thyroid cartilage)
What are the suprahyoid muscles?
- mylohyoid
- geniohyoid
- stylohyoid
- digastric (anterior and posterior bellies)
What are the general actions of the suprahyoid muscles?
- superior attachments fixed: elevate the hyoid bone
- hyoid fixed: assist in depressing (lowering) the mandible
What are the infrahyoid muscles?
- sternohyoid
- sternothyroid
- thyrohyoid
- omohyoid
What are the general actions of the infrahyoid muscles?
depress the hyoid bone
What are the two-headed muscles of the hyoids?
- digastric (anterior and posterior bellies)
- omohyoid (superior and inferior bellies)
Which muscle group attaches the hyoid to the skull?
suprahyoids
The prefix “omo” refers to:
the shoulder (inferior belly of omohyoid attaches to superior border of he scapula near the suprascapular notch)
What’s between the muscle bellies of each of the two-headed hyoid muscles?
intermediate tendons
What are the muscles of the superficial layer of the back?
- trapezius
- latissimus dorsi
- levator scapula
- rhomboid major (and minor)
What are the intermediate muscles of the back, and what do they do?
accessory muscles of respiration
- serratus posterior superior
- serratus posterior inferior
What muscles are in the superficial layer of the deep back muscles?
- splenius capitis
- splenius cervicis
What muscles are in the intermediate layer of the deep back muscles?
3 columns of muscles collectively called the erector spinae (aka paraspinals). Medial to lateral, they are:
- spinalis
- longissimus
- iliocostalis
What muscles are in the deep layer of the deep back muscles and have a superomedial fibre direction?
(collectively called the transversospinalis muscles) from superficial to deep:
- semispinalis (capitis, cervicis, thoracis)
- multifidus
- rotatores
What muscles are in the deep layer of the deep back muscles and have a vertical fibre direction?
- interspinales
- intertransversarii
Where are the muscles in the deep layer of the deep back muscles, and generally where do they attach?
superomedial or vertical fibre direction
- found in the groove between the spinous and transverse processes (the laminar groove)
- some (SMR) attach from the TVP to the SP of a superior vertebrae
- some (inters) attach from SP-SP or TVP-TVP
What are the attachments of serratus posterior superior? What is it deep to? Superficial to?
- M: SPs of C7-T3
- L: superior borders of ribs 2-5
- deep to rhomboids
- superficial to erector spinae
What are the attachments of serratus posterior inferior? What is it deep to? Superficial to?
- M: SPs of T11-L2
- L: lower 4 ribs
- deep to latissiumus/thoracolumbar fascia
- superficial to the erector spinae
What are the actions of serratus posterior superior?
elevates ribs 2-5 (supports breathing – forced inspiration)
What are the actions of serratus posterior inferior?
draws ribs down and back (with forced expiration – coughing, sneezing, blowing nose…)
What does splenium mean?
bandage (gr.)
What are the attachments and actions of splenius capitis?
- I: SPs of C4-T2
- S: mastoid process and lateral superior nuchal line
- unilateral contraction: ipsilateral rotation
- bilateral contraction: extension of the neck
What are the attachments and actions of splenius cervicis?
- S: C1-C4 TVPs (posterior tubercles)
- I: SPs of T3-T5
- unilateral contraction: ipsilateral rotation
- bilateral contraction: extension of the neck