Lecture 7: Superficial Back Flashcards
Two surfaces of scapula
costal and dorsal
Three borders of scapula
superior, lateral, and medial
Three angles of scapula
lateral , superior and inferior
Three processes of scapula
acromion, spine, coracoid process
- Located on the superior border of the scapula just medial to the coracoid process.
- Bridged by the superior transverse scapular ligament to form a foramen for the suprascapular nerve
Suprascapular notch
- Located at the lateral free edge of the spine
- Traversed by the suprascapular nerve and artery (headed to infrapsinatus muscle)
Spinoglenoid notch (a.k.a. greater scapular notch)
- articulates with the head of the humerus to form the glenohumeral joint
- deepened slightly by a fibro cartilaginous glenoid labrum
Glenoid cavity
Action of trapezius muscle
Acts to suspend the shoulder girdle, elevate (“shrugging”), depress or retract the scapula, rotate the glenoid cavity upward during abduction of the humerus above the horizontal.
Blood supply of trapezius
Nerve supply of trapezius
Blood: superficial branch of the transverse cervical artery.
Nerve: Accessory nerve (cranial nerve XI)
-supplied by C3 & C4 spinal nerves for proprioception.
Action of latissimus dorsi muscle
Extends, adducts, and medially rotates the humerus; it also raises the body toward the arms during climbing (“pull-ups”)
Blood supply of latissimus dorsi
Nerve supply of latissimus dorsi
Blood: thoracodorsal artery
Nerve: thoracodorsal nerve
(C6-C8; posterior cord)
Action of Rhomboid major and rhomboid minor
Retract scapula (pull it medially) and rotate it to depress glenoid cavity; also fix scapula to thoracic wall.
Blood supply of Rhomboid major and rhomboid minor
Nerve supply of Rhomboid major and rhomboid minor
Blood: dorsal scapular artery
Nerve: dorsal scapular nerve (C5)
Action of levator scapulae
Elevates the scapula
Blood supply of levator scapulae
Nerve supply of levator scapulae
Blood: dorsal scapular artery
Nerve: dorsal scapular nerve (C5)
(also from anterior rami spinal nerves C3-C4.)
What nerve injury leads to, weakness in trapezius, may appear as drooping of the shoulder , inability to raise the arm above the head because of impaired rotation of scapula , or weakness in attempting to raise the shoulder ( i.e. shrug the shoulder against resistance )
an injury of the accessory nerve ( XI)
What nerve injury leaads to, A weakness in or an inability to use the latissimus dorsi, diminishes the capacity to pull the body upward while climbing or doing a pull up .
an injury to the thoracodorsal nerve
What nerve injury leads to, which innervates the rhomboids , may result in a lateral shift in the position of scapula on the affected side
An injury to the dorsal scapular nerve
Action of serratus posterior superior
It elevates the upper ribs.
Action of serratus posterior inferior
It depresses the lower ribs
Blood supply of serratus posterior superior and inferior
Nerve supply of serratus posterior superior and inferior
Blood: intercostal arteries
Nerve: anterior rami of intercostal nerves
Triangle of auscultation boundaries
medial - trapezius muscle
inferior - latissimus dorsi
lateral - medial border of scapula and rhomboid major muscle
Triangle of auscultation importance
Auscultation of breath sounds: a good place to position a stethoscope to listen to posterior segments of the lung
Lumbar traingle of Petit boundaries
Latissimus dorsi muscle - medial
External oblique muscle - lateral
Iliac crest – inferior
Lumbar traingle of Petit importance
Site of lumbar hernia
