Muscles and Anatomy of the Back and Shoulder

This set of flashcards covers the key vocabulary and concepts related to the back and shoulder muscles, their anatomy, functions, and clinical implications.

Extrinsic muscles

Muscles that originate from outside the back and are primarily responsible for moving the upper limb.

Intrinsic muscles

Muscles that develop embryologically in the back and are responsible for movements of the vertebral column.

Suboccipital triangle

A small, deep triangle at the base of the skull, bounded by suboccipital muscles.

Trapezius muscle

A broad, flat, triangular muscle that elevates, retracts, and rotates the scapula.

Latissimus dorsi

A muscle that extends, adducts, and medially rotates the upper limb.

Rhomboids

Muscles that retract and rotate the scapula.

Levator scapulae

A muscle that elevates the scapula.

Serratus posterior

Muscles that assist in respiration by elevating or depressing the ribs.

Erector spinae

A group of muscles that are primary extensors and lateral flexors of the vertebral column.

Glenohumeral joint

A synovial ball and socket joint between the head of the humerus and the glenoid cavity of the scapula.

Sternoclavicular joint

A synovial joint between the proximal end of the clavicle and the clavicular notch of the sternum.

Acromioclavicular joint

A small synovial joint between the acromion and the acromial end of the clavicle.

Blood circulation to the shoulder

The blood supply that nourishes the muscles and structures around the shoulder joint.

Innervation

The supply of nerves to a muscle or a group of muscles.

Clinical Correlation (Trapezius injury)

Drooping of the shoulder and inability to raise the arm above the head due to accessory nerve injury.

Clinical Correlation (Latissimus dorsi injury)

Inability to pull the body upright when climbing or doing a pull-up due to thoracodorsal nerve injury.