Muscles of the Thoracic Wall Quiz

Intrinsic Muscles of the Thoracic Wall

• Includes the internal intercostal muscles, innermost intercostal muscles, and subcostal muscles.

Function of External Intercostal Muscles

• Elevate the ribs during inhalation, increasing thoracic cavity volume and aiding in breathing.

Anatomic Space Between Two Ribs

• Known as the intercostal space.

Closure of Intercostal Spaces

• The internal intercostal muscles help close the intercostal spaces during expiration.

Structures Between Internal and Innermost Intercostal Layers

• Intercostal veins, arteries, and nerves travel in this space.

Muscle Responsible for Scapula Elevation and Rotation

• The trapezius muscle elevates and rotates the scapula, especially during arm abduction.

Muscle Originating from T6-T12 and Other Areas

• The latissimus dorsi originates from the spinous processes of T6-T12, iliac crest, thoracolumbar fascia, and inferior three ribs.

Superficial Trapezoidal-Shaped Back Muscle

• The trapezius muscle is the most superficial back muscle, forming a trapezoid shape.

Muscle Pulling the Scapula Inferiorly

• The rhomboid major muscle is primarily responsible for pulling the scapula inferiorly.

Muscle Originating from Skull and Spinal Processes

• The trapezius also originates from the skull, ligamentum nuchae, and the spinous processes of C7-T12.