Superficial Back and Extrinsic Shoulder Muscles

These flashcards cover key terminology and definitions related to the superficial back and extrinsic shoulder muscles, their functions, and anatomical relationships.

Superficial back muscles

Muscles that primarily move the upper limb, including trapezius, latissimus dorsi, and rhomboids.

Pectoral girdle

The structure formed by the shoulder blade (scapula) and clavicle.

Triangle of auscultation

A region on the back where the lung sounds can be more easily heard due to a thin area formed by the latissimus dorsi, trapezius, and the medial border of the scapula.

Scapulothoracic joint

The fascial connection that allows the scapula to move against the thoracic wall, not a true bony joint.

Upward rotation

Movement of the scapula that results in the inferior angle moving laterally while the glenoid fossa faces superiorly.

Downward rotation

Movement that returns the scapula to its resting position from upward rotation.

Rhomboid major and minor muscles

Muscles that retract and medially rotate the scapula.

Serratus anterior muscle

Muscle that protracts the scapula and holds it against the thoracic wall.

Trapezius muscle

A major muscle of the back responsible for stabilizing, elevating, retracting, and rotating the scapula.

Latissimus dorsi muscle

A muscle that extends, adducts, and medially rotates the arm at the shoulder.

Superficial back muscles

Muscles that primarily move the upper limb, including trapezius, latissimus dorsi, and rhomboids.

Pectoral girdle

The structure formed by the shoulder blade (scapula) and clavicle.

Triangle of auscultation

A region on the back where the lung sounds can be more easily heard due to a thin area formed by the latissimus dorsi, trapezius, and the medial border of the scapula.

Scapulothoracic joint

The fascial connection that allows the scapula to move against the thoracic wall, not a true bony joint.

Upward rotation

Movement of the scapula that results in the inferior angle moving laterally while the glenoid fossa faces superiorly.

Downward rotation

Movement that returns the scapula to its resting position from upward rotation.

What is the action of the Rhomboid minor muscle?

Retracts and medially rotates the scapula.

What is the origin of the Rhomboid minor muscle?

Nuchal ligament, spinous processes of C7-T1 vertebrae.

What is the insertion of the Rhomboid minor muscle?

Medial border of the scapula, superior to the spine of the scapula.

What is the innervation of the Rhomboid minor muscle?

Dorsal scapular nerve (C4, C5).

What is the action of the Rhomboid major muscle?

Retracts and medially rotates the scapula.

What is the origin of the Rhomboid major muscle?

Spinous processes of T2-T5 vertebrae.

What is the insertion of the Rhomboid major muscle?

Medial border of the scapula, inferior to the spine of the scapula.

What is the innervation of the Rhomboid major muscle?

Dorsal scapular nerve (C4, C5).

What is the action of the Serratus anterior muscle?

Protracts the scapula and holds it against the thoracic wall.

What is the origin of the Serratus anterior muscle?

External surfaces of lateral parts of 1st-8th ribs.

What is the insertion of the Serratus anterior muscle?

Anterior surface of medial border of scapula.

What is the innervation of the Serratus anterior muscle?

Long thoracic nerve (C5, C6, C7).

What is the action of the Trapezius muscle?

Stabilizing, elevating, retracting, and rotating the scapula.

What is the origin of the Trapezius muscle?

Medial 1/3 of superior nuchal line, external occipital protuberance, nuchal ligament, spinous processes of C7-T12 vertebrae.

What is the insertion of the Trapezius muscle?

Lateral 1/3 of clavicle, acromion, spine of the scapula.

What is the innervation of the Trapezius muscle?

Accessory nerve (CN XI) (motor) and C3, C4 spinal nerves (pain and proprioception).

What is the action of the Latissimus dorsi muscle?

Extends, adducts, and medially rotates the arm at the shoulder.

What is the origin of the Latissimus dorsi muscle?

Spinous processes of T7-T12 vertebrae, thoracolumbar fascia, iliac crest, last 3-4 ribs, inferior angle of scapula (sometimes).

What is the insertion of the Latissimus dorsi muscle?

Floor of the intertubercular groove of the humerus.

What is the innervation of the Latissimus dorsi muscle?

Thoracodorsal nerve (C6, C7, C8).