Musculus serratus dorsalis cranialis
Thin fan-shaped inspiratory muscle drawing cranial ribs forward and outward to expand the ribcage. Becomes important during exercise for maximum chest expansion.
Origin: Thoracolumbar fascia from spinous processes of T1-T8
Insertion: Lateral surface of ribs 5-11
Action: Draws ribs cranially and laterally, assisting inspiration
Innervation: Intercostal nerves
In horses with Recurrent Airway Obstruction, increased work of breathing causes hypertrophy and fatigue of accessory respiratory muscles.
In horses with Recurrent Airway Obstruction, increased work of breathing causes hypertrophy and fatigue of accessory respiratory muscles. Signs include: Heave line along costal arch; labored breathing at rest; prolonged recovery after exercise; nostril flaring at rest; double expiratory effort.
See the Cranial Dorsal Serratus on our interactive 3D horse model. Open 3D Model