External Intercostals - Horse Anatomy | Inside The Equine
Muscular System

External Intercostals

Musculi intercostales externi

Overview

Muscles between the ribs with fibers running caudoventrally. Primary muscles of inspiration, drawing ribs cranially and outward. Active with every breath.

Anatomical Details

Origin: Caudal border of each rib

Insertion: Cranial border of the adjacent caudal rib

Action: Elevate the ribs during inspiration, expanding the thorax

Innervation: Intercostal nerves

Common Conditions & Injuries

Intercostal tears / rib fractures

Kicks or falls tear intercostal muscles or fracture ribs, causing severe pain with each breath.

Frequently Asked Questions

What is Intercostal tears / rib fractures in horses?

Kicks or falls tear intercostal muscles or fracture ribs, causing severe pain with each breath. Signs include: Shallow breathing; reluctance to move; pain between ribs on palpation; possible subcutaneous emphysema; may mimic colic; fever if pleuritis develops.

Explore This Structure in 3D

See the External Intercostals on our interactive 3D horse model. Open 3D Model