Atlas (C1) vs Diaphragm

Property Atlas (C1) Diaphragm
Latin Name Atlas Musculus diaphragma
Type Bone Muscle
Body System Skeletal Muscular
Body Region Spine Thorax
Function The first cervical vertebra that supports the skull. Allows nodding movements (flexion and extension) of the head at the atlanto-occipital joint. The primary muscle of respiration. Contraction flattens the dome-shaped muscle, increasing thoracic volume and creating negative pressure to draw air into the lungs during inspiration.
Clinical Significance Jefferson fractures (burst fractures of the atlas) result from axial loading. Atlanto-occipital dislocation is usually fatal. Congenital anomalies include atlas assimilation (occipitalization). Diaphragmatic hernias allow abdominal organs to enter the thoracic cavity. Phrenic nerve paralysis causes diaphragmatic elevation. Hiccups result from involuntary diaphragmatic spasms.
FMA ID 12519 13295