Superficial Back Muscles Flashcards
Trapezius
Innervated by the Accessory nerve ( Cranial Nerve ELEVEN) and Cervical Spine Nerves C3 and C4
Latissimus Dorsi
Innervated by Thoracodorsal nerve (C6-C8)
Levator Scapulae
Innervated by Dorsal Scapular nerve C5 or Cervical nerves C3-C4
Rhomboid Minor and Major
Innervated by Dorsal Scapular nerve (C4-C5)
Trapezius blood supply
Superficial branch of transverse Cervical artery
Latissimus Dorsi Blood supply
Thoracodorsal artery
Levator Scapulae Blood supply
Transverse and Anterior Cervical nerves
Rhomboid Minor and Major muscles blood supply
Deep branch of the Transverse Cervical artery or the Dorsal Scapular artery
Trapezius function
Assist in rotating the scapula during abduction of the humerus above the horizontal
Elevate, adduct, depress the scapula. Has fibers the Upper, middle and lower fibers that do this.
Latissimus Dorsi Function:
EAM- Extend, Adduct, and medially rotates the humerus to move the arm.
Levator Scapullae Function
Elevate the Scapula and tilt the Glenoid fossa anteriorly
Rhomboid minor and major have the same function
Retracts/ Adducts and elevates the scapula
Types of superficial/Extrinsic back muscles
*****Superficial Appendicular /Extrinsic( further separated in first layer and 2nd layer)
First layer: Trapezium and Latissimus Dorsi
Second layer: Levator Scapulae and Rhombid minor and Major
*****Superficial Respiratory/Intermediate Extrinsic muscles
- Serratus Posterior Superior muscle
- Serratus Posterior Inferior muscle
Serratus Posterior Superior Muscle
Innervated by the Anterior/Ventral Rami of Upper Thoracic/ Intercostal nerves T2-T5
Blood supply: Segmental supply from the intercostal arteries
Function: Elevates ribs 2-5
Serratus Posterior Inferior Muscle
Innervated by the Ventral/Rami of LOWER throracic/intercostal nerves of T9-T12
Blood supply: Segmental supply from the intercostal arteries
Function: Depresses ribs 9-12. Prevents the lower ribs from elevating when the diaphragm contrasts.
