1. Which muscle is primarily responsible for the flexion of the vertebral column? A) Rectus abdominis B) Latissimus dorsi C) Trapezius D) Erector spinae Answer: A) Rectus abdominis Rationale: The rectus abdominis muscle is the main muscle that flexes the vertebral column. It is located in the anterior abdominal wall and contracts to pull the rib cage closer to the pelvis. 2. The trapezius muscle is classified as a muscle of the: A) Appendicular musculature B) Axial musculature C) Lower limb D) Anterior thorax Answer: B) Axial musculature Rationale: The trapezius is part of the axial musculature, which includes muscles along the central axis of the body involved in movement and support of the spine and skull. 3. Which of the following muscles is not considered part of the axial musculature? A) Sternocleidomastoid B) Pectoralis major C) External oblique D) Splenius capitis Answer: B) Pectoralis major Rationale: The pectoralis major is a muscle of the appendicular musculature, specifically of the upper limb, and is not part of the axial musculature which consists of muscles that support the head, neck, and vertebral column. 4. During an inhalation, which muscle decreases the volume of the thoracic cavity? A) Diaphragm B) External intercostals C) Internal intercostals