Summary of Veterinary Aorta and Arterial Branches

## Introduction The thoracic and cervical arterial network supplies blood to the neck, shoulder, thoracic wall, and related muscles and organs in domestic mammals. This material focuses on named branches that arise in the cervicothoracic and axillary regions (excluding general coverage of the aorta and major arterial trunks already covered elsewhere). We will break down relevant arteries, their branches, distributions, and clinical or practical significance for a not-attending student. > Definition: The term “arterial branch” refers to a blood vessel that arises from a larger artery and supplies a specific region, muscle, or organ. ## Major branches covered here (overview) - **A. cervicalis profunda** (deep cervical artery) - **A. scapularis dorsalis** (dorsal scapular artery) - **A. vertebralis** (vertebral artery) - **A. cervicalis superficialis** (superficial cervical artery) - **A. thoracica interna** (internal thoracic artery) - **A. intercostalis suprema** (supreme intercostal artery) - **A. axillaris** (axillary artery) — focus on its role as the main artery of the thoracic limb and its immediate branches ### How to approach these arteries 1. Origin (from which more proximal vessel they arise) 2. Course (direction and key anatomic relationships) 3. Branches (major named branches and muscle/organ targets) 4. Areas supplied (cutaneous, muscular, visceral targets) 5. Clinical relevance (surgical landmarks, common variations) ## A. cervicalis profunda (deep cervical artery) - Origin: arises from the costocervical trunk or a nearby cervicothoracic branch in many domestic species. - Course: runs dorsocranially toward deep neck muscles. - Distribution: supplies deep neck muscles and contributes to the vertebral canal blood supply. - Clinical note: important in procedures near the cranial thoracic inlet. ## A. scapularis dorsalis (dorsal scapular artery) - Origin: often a branch of the subclavian or from a trunk near the first rib region. - Key branches and targets: - r. deltoideus — supplies m. deltoideus and associated shoulder muscles - r. ascendens — supplies m. trapezius cervicis - r. prescapularis — supplies prescapular area muscles - r. suprascapularis — supplies lateral scapular muscles (supraspinatus, infraspinatus) - Course: runs toward the dorsal aspect of the scapula and shoulder. - Practical application: palpation/surgical approaches to the shoulder must respect this artery; it often forms anastomoses with suprascapular branches. ## A. vertebralis (vertebral artery) - Origin: branch of the subclavian artery; typically has right and left components (a. vertebralis dextra, a. vertebralis sinistra). - Course: passes cranially through foramina of the cervical vertebrae toward the brainstem and forms the basilar artery after joining the contralateral vessel. - Branches/relations: supplies muscles of the neck, spinal cord segments, and vertebral column structures; contributes to cerebral circulation via a. basilaris. - Clinical note: variation in origin and size can affect cerebral ischemia models in animal research (e.g., rabbit studies). ## A. cervicalis superficialis (superficial cervical artery) - Typical branches and their targets: - r. deltoideus — m. pectoralis descendens and deltoideus - r. ascendens — m. trapezius cervicis - r. prescapularis — superficial prescapular area - r. suprascapularis — lateral scapular musculature - Distribution: superficial neck, shoulder, and cranial thoracic limb territories. - Table: comparison with a. scapularis dorsalis | Feature | A. scapularis dorsalis | A. cervicalis superficialis | | --- | --- | --- | | Typical origin | Near first rib / subclavian vicinity | Subclavian region or superficial trunk | | Main target | Dorsal scapula and lateral shoulder muscles | Superficial neck and cranial shoulder region | | Notable branches | r. suprascapularis, r. deltoideus | r. prescapularis, r. ascendens | ## A. thoracica interna (internal thoracic artery) — select