Scapular And Deltoid Regions Flashcards
What are the superficial muscles associated with the scapular region?
Trapezius
Latissimus dorsi
The trapezius m. acts to retract the scapula; superior fibers pull upward on a lateral angle and inferior fibers pull downward on the base of the spine, rotating the glenoid cavity upward; this motion typically accompanies what motion of the arm?
Abduction
What muscle’s inferior fibers prevent upward displacement of the shoulder when weight of the body tends to produce this action, such as with hanging by the arms or using crutches?
Latissimus dorsi
What are the deep extrinsic muscles assoociated with the scapular region?
Levator scapulae
Rhomboideus minor
Rhomboideus major
Serratus anterior
If, during protraction of the scapula, the inferior angle moves forward faster than the remainder of the medial border, the scapula is upwardly rotated. This upward rotation is the most important action of which of the following muscles?
A. Levator scapulae m. B. Serratus anterior m. C. Rhomboideus major m. D. Rhomboideus minor m. E. Deltoid m.
B. Serratus anterior m.
The serratus anterior is normally aided by fibers of the _____ muscle that lifts the lateral angle of the scapula
Trapezius
Origin of deltoid m.
Lateral 1/3 of clavicle, acromion and spine of scapula
The deltoid originates on the lateral 1/3 of the clavicle, acromion, and spine of scapula. This is the same as the insertion point of what muscle?
Trapezius m.
Insertion of deltoid
Deltoid tuberosity on body of humerus
Innervation of deltoid m.
Axillary n. (C5-6)
Actions of deltoid m.
Anterior fibers flex and medially rotate arm
Middle fibers abduct arm
Posterior fibers extend and laterally rotate arm
T/F The deltoid probably does not participate in rotation when only rotation is desired
True
Origin of supraspinatus
Supraspinatus fossa and from fascia covering this muscle
Insertion of supraspinatus
Uppermost of the 3 facets of greater tubercle of humerus
[tendon of insertion forms uppermost part of rotator cuff]
Origin of infraspinatus
Infraspinatus fossa and from the fascia covering the same muscle
Insertion of infraspinatus
Middle facet on greater tubercle of humerus; forms middle part of rotator cuff
Origin of teres minor m.
Middle 1/2 of lateral border of scapula
Insertion of teres minor
Lowest facet on greater tubercle of humerus; forms lowest part of rotator cuff
Origin of teres major
Lower 1/3 of lateral border of scapula
Origin of subscapularis m.
Costal surface of scapula
Insertion of subscapularis
Lesser tubercle of humerus and its crest; forms anterior part of rotator cuff
Origin/insertion/innervation action of:
Supraspinatus m.
Origin: supraspinatus fossa and from fascia covering the same muscle
Insertion: uppermost of 3 facets of greater tubercle of humerus
Innervation: suprascapular n. (C5-6)
Actions: abduction of arm
Origin/insertion/innervation action of:
Infraspinatus m.
Origin: infraspinatus fossa and from fascia covering the same muscle
Insertion: middle facet on greater tubercle of humerus
Innervation: suprascapular n.
Actions: lateral rotation of arm
Origin/insertion/innervation action of:
Teres minor m.
Origin: middle 1/2 of lateral border of scapula
Insertion: lowest facet on greater tubercle of the humerus
Innervation: axillary n.
Actions: lateral rotation of arm; also a weak adductor of the arm
Origin/insertion/innervation action of:
Teres major m.
Origin: lower third of lateral border of scapula
Insertion: passes around medial side of humerus with latissimus dorsi to attach to the crest of the lesser tubercle of the humerus
Innervation: lower subscapular n. (C5-6)
Actions: adduction, medial rotation and extension of arm; apparently only acts when these movements are resisted
Origin/insertion/innervation action of:
Subscapularis m.
Origin: costal surface of scapula
Insertion: tendon passes across front of shoulder joint, forming anterior part of rotator cuff, to insert into the lesser tubercle of humerus and its crest
Innervation: upper and lower subscapular n.
Actions: medial rotation of arm
What are the 4 borders of the quadrangular space?
Superior border: lateral border of scapula and capsule of shoulder joint
Lateral border: surgical neck of humerus
Inferior border: teres major m.
Medial border: long head of triceps brachii
What are the contents of the quadrangular space
Axillar n.
Posterior humeral circumflex a. and v.
What branch of the thyrocervical trunk supplies the levator scapulae, trapezius, and rhomboidei mm?
Transverse cervical a.
What branch of the thyrocervical trunk supplies the supraspinatus and infraspinatus
Suprascapular a.
What 2 arteries does the suprascapular a. anastomose with?
Deep branch of transverse cervical a.
Circumflex scapular branch of subscapular a.
What branch of the thoracoacromial trunk supplies the deltoid m.?
Deltoid branch
What artery arising the axilla supplies the serratus anterior m.?
Lateral thoracic a.
What are the 2 branches of the subscapular a.?
Thoracodorsal a.
Circumflex scapular a.
The subscapular a. has 2 branches: the thoracodorsal a. and the circumflex scapular a. What does the thoracodorsal a. supply?
Subscapularis m.
Teres major m.
Latissimus dorsi m.
Serratus anterior m.
The subscapular a. has 2 branches: the thoracodorsal a. and the circumflex scapular a. What does the circumflex scapular a. supply?
Infraspinatus m.
The subscapular a. has 2 branches: the thoracodorsal a. and the circumflex scapular a. What does the circumflex scapular a. anastomose with?
Suprascapular a.
What does the posterior humeral circumflex a. supply and anastomose with?
Supplies deltoid m.
Anastomoses with anterior humeral circumflex a.
Deep lymphatic vessels of the shoulder follow the blood vessels and therefore drain largely into the _______ lymph nodes
Axillary
