Scalene Muscles Flashcards
In which triangle of the neck are the scalene muscles found?
Posterior triangle of the neck
What is the action of the scalene muscles?
Flexion of neck and accessory muscles of respiration (involved in elevating first and second ribs to increase intrathoracic volume)
Why does the first rib have the scalene tubercle?
This is where the subclavian artery and vein sit
What is the action of the anterior scalene muscle?
Elevation of first rib, anterior and lateral flexion of neck
What are the attachments of the anterior scalene muscle?
Originates from anterior tubercle of transverse process of C3-C6, attaches to scalene tubercle on inner border of first rib
What is the innervation of the anterior scalene muscle?
Anterior rami of C5-C6
What is the action of the middle scalene muscle?
Elevation of first rib, lateral flexion of neck
What are the attachments of the middle scalene muscle?
Originates from posterior tubercle of transverse process of C2-C7, attaches to scalene tubercle of first rib
Which scalene muscle is the biggest?
Middle scalene (several bellies)
What is the innervation of the middle scalene?
Anterior rami of C3-C8
What is the action of the posterior scalene muscle?
Elevation of second rib, lateral flexion of neck
What are the attachments of the posterior scalene?
Originates from posterior tubercle of transverse process of C5-C7, attaches to second rib
What is the innervation of the posterior scalene?
Anterior rami of C6-C8
Which structures pass between the anterior and middle scalenes?
Subclavian artery and brachial plexus
What is an interscalene block and how is it carried out?
. Administer local anaesthetic into brachial plexus (between anterior and middle scalenes) when doing upper limb surgery
. Insert needle into the brachial plexus at the level of the cricoid cartilage
