8.29.11+-+Self+Study...+Back+and+Shoulder+Regions


 * Objectives**


 * 1) Identify the following bony landmakrs**
 * **scapula**
 * **head** - The head of the scapula is the bone into which the glenoid fossa is formed.
 * **neck** - The neck of the scapula is the short area of bone that leads from the body of the scapula to the head.
 * **body**
 * **spine**
 * **coracoid process**
 * **acromion**
 * **subscapular fossa**
 * **supraspinous fossa**
 * **infraspinous fossa**
 * **glenoid fossa**
 * **suprascapular notch**
 * **spinoglenoid notch** - The notch that runs over the neck of the scapula
 * **humerus**
 * **greater tubercle**
 * **lesser tubercle**
 * **intertubercular sulcus (aka bicipital groove)**
 * **deltoid tuberosity**


 * 2) List and recite the proximal/medial attachments, distal/lateral attachments, innervation and main action(s) of the following muscles of the scapular and deltoid regions [from coa 4th ed)**
 * **deltoid**
 * **teres major**
 * **supraspinatus**
 * **infraspinatus**
 * **teres minor**
 * Muscle || Proximal/medial attachment || Distal/lateral attachment || Innervation || Main action ||
 * Deltoid || Lateral third of the clavicle, acromion, and spine of the scapula || Deltoid tuberosity of humerus || Axillary nerve (c5 and c6) || Anterior part: flexes and medially rotates arm. Middle part: abducts arm. Posterior part: extends and laterally rotates arm ||
 * Teres major || Dorsal surface of inferior angle of scapula || Medial lip of intertubercular groove of humerus || Lower subscapular nerve (c6 and c7) || Adducts and medially rotates arm ||
 * Supraspinatus || Supraspinous fossa of scapula || Superior facet on greater tubercle of humerus || Suprascapular nerve (c5 and C6) || Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles ||
 * Infraspinatus || Infraspinous fossa of scapula || Middle facet on greater tubercle of humerus || Axillary nerve (C5 and C6) || Laterally rotate arm; help to hold humeral head in glenoid cavity of scapula ||
 * Teres minor || Superior part of lateral order of scapula || Inferior facet on greater tubercle of humerus || Axillary nerve (C5 and C6) || Laterally rotate arm; help to hold humeral head in glenoid cavity of scapula ||
 * 3. Define the term “rotator cuff”. [COA 4th ed]**

4 of the scapulohumeral muscles - supraspinatus, infraspinatus, teres minor, and subscapularis (SITS) are rotator cuff muscles because they form a musculotendinous rotator cuff around the glenohumeral joint. Tendons of the rotator cuff muscles blend with articular capsule of the glenohumeral joint to reinforce it, protecting the joint and giving it stability, with their tonic contraction holding the relatively large head of the humerus in the small, shallow glenoid cavity of the scapula during arm movements. Reinforces the capsule anteriorly, superiorly, and posteriorly as it provides active support for the glenohumeral joint.


 * 4. Name and order the four “SITS” muscles whose distal tendons form the rotator cuff.**
 * Describe the rotator cuff function of these muscles.**

//In no particular order:// If someone could provide a more-official answer to this question that would be appreciated.
 * Subscapularis || Internally rotates humerus ||
 * Supraspinatus || Externally rotates and abducts humerus ||
 * Infraspinatus || Externally rotates humerus ||
 * Teres minor || Externally rotates humerus ||
 * These actions are //not// from a class text, but were taken from various sites on the internet and do not represent official information.

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 * 5. List the only branch off the first part of the axillary artery.**


 * 1) Superior thoracic artery


 * 6. List the two arteries which branch off the second part of the axillary artery.**


 * 1) Thoracoacromial artery
 * 2) Lateral thoracic arteries
 * These pass medial and lateral to the pectoralis minor, respectively


 * 7. List the three arteries which branch off the third part of the axillary artery.**
 * 1) Subscapular (the largest branch of the axillary artery)
 * 2) Anterior circumflex humeral artery
 * 3) Posterior circumflex humeral artery

*Note: For objectives 5-7 see //Atlas of Human Anatomy// (Netter, 5th ed.) plate 415.

 * 8. Identify the following arteries of the scapular and deltoid regions:**
 * **posterior humeral circumflex a.**
 * **profunda brachii a.**
 * **subscapular a.**
 * **circumflex scapular branch of**
 * **subscapular a.**
 * **thoracodorsal branch of subscapular a.**
 * **suprascapular a.**
 * **transverse cervical a.**
 * **dorsal scapular a. (branch of transverse cervical a.)**


 * 9. Recognize the following nerves of the scapular and deltoid regions: [find images!]**
 * axillary n.**
 * suprascapular n.**


 * 1) Axillary n. - Origin is terminal branch of posterior cord, receiving fibers from C5 and C6. Passes to posterior aspect of arm through quadranular space in company with posterior circumflex humeral artery and then winds around surgical neck of humerus; gives rise to lateral brachial cutaneous nerve. Innervates inferior portio nof subscapularis and teres major. [coa 4th ed]
 * 2) Suprascapular n. - origin forms superior trunk, receiving fiers from C5, C6, and often C4. course passes laterally across posterior triangle of neck, through scapular notch under superior transverse scapular ligament. Innervates supraspinatus, infraspinatus, and glenohumeral (shoulder) joint. [coa 4th ed]


 * 10.Describe the relationship of the suprascapular a. and n. with the suprascapular (aka**
 * transverse scapular) ligament.**


 * 11. Define the boundaries of the triangular and quadrangular spaces.**
 * .... Identify the structure(s) passing through each space.**