Ch. 3- Superficial Back 9/18

Question 1

trapezius

Answer 1

O: along the midline posteriorly from the external occipital protuberance ands superior nuchal line, via the nuchal ligament to cervical and upper thoracic vertebral spinous processes and all remaining spinous process to TV12
I: Lateral superior border of the clavicle, acromion and spine of the scapula
A: Superior fibers: elevates scapula, assists in upward rotation of glenoid cavity
Middle fibers: retraction of the scapula
Inferior fibers: upward rotation of the glenoid cavity
N: cranial nerve Xi (spinal accessory-motor)
Ventral rami of spina nerves C3 and C4 (Sensory)

NOTE: CN XI and spinal nerves C3 and C4 form a network of nerves on the ventral surface of the trapezius known as SUBTRAPEZIAL PLEXUS

NOTE: the integrity of hte psinal accessory nerve is tested by asking the patient to shurg his/her shoulders against resitance.

Question 2

Latissimus Dorsi

Answer 2

O: Spinous processes T6-T 12, via thoracolumbar fascia to all lumbar and sacral spinous processes, posterior one-third of the crest of the ilium, outer surfaces of ribs 9-12 and the inferior angle of the scapula
I: Floor of the Intertubercular (bicipital) groove of the humerus
A: adducts, extends, and medially rotates the humerus
N: Thoracodorsal Nerve

Question 3

Levator Scapulae

Answer 3

O: Transverse processes of cervical vertebrae 1-4
I: Medial border of scapula from superior angle to root of spine
A: Elevates scapula, assists in downward rotation of the glenoid cavity
N: Dorsal scapular nerve (C5), 3rd and 4th cervical nerve

Question 4

Rhomboideus Minor

Answer 4

O: spinous processes C7 and T1
I: Medial border of scapula at root of spine
A: retracts scapula, downwardly rotates the glenoid cavity
N: Dorsal Scapular Nerve

Question 5

Rhomboideus Major

Answer 5

O: Spinous Processes T2-T5
I: Medial border of scapula at root of spine
A: retracts scapula, downwardly rotates glenoid cavity
N: Dorsal Scapular Nerve

Question 6

Triangle of Auscultation

Answer 6

area approximately loocated superficial to the posterior sixth intercostal space, which because it is devoid of overlying muscle, eases auscultation 
- Borders: 
Medial: trapezius
Lateral: Rhomboideus Major
Inferior: Latissimus Dorsi

Question 7

Transverse Cervical Artery

Answer 7

• a branch of the thyrocervical trunk (1st portion of subclavian artery). It passes posteriorly within the posterior triangle of the neck and slips deep to the trapezius muscle. Undercover the trapezius, in approximately 50% of the cases, the transverse cervical artery will divide into superficial and deep branches
• superficial branch: descends in company with the spinal accessory nerve on the deep surface of the trapezius. Inferiorly the superficial branch is ramified (aided in its circulation) by dorsal branches of posterior intercostal arteries
• deep branch- runs deep to the levator scapulae and rhomboideus muscles, accompanies the dorsal scapular nerve and participates in the scapular anastomosis

Question 8

Dorsal Scapular

Answer 8

• arises from the 2nd or 3rd portion of the subclavian artery and courses posteriorly between portions of the brachial plexus and neck musculature. The artery then follows the path of the deep branch of the transverse cervical artery
  NOTE: from the above descriptions it should be noted that the dorsal scapular artery arises either from the transverse cervical artery or the subclavian artery directly. Due to this variation some texts refer to the deep branch of the transverse cervical artery as the descending or dorsal scapular artery

Question 9

Thoracodorsal artery

Answer 9

a branch of the subscapular artery (3rd portion of the axillary artery). it accompanies the thoracodorsal nerve on the ventral surface of the latissimus dorsi muscle

Question 10

Nerves of superficial back

Answer 10

• excluding the trapezius, nerves which innervate muscles of the upper limb and superficial back are derived from ventral rami of spinal nerves associated with the brachial plexus