Which of the following veins crosses perpendicularly the superficial surface of the sternocleidomastoid surface directly beneath the platysma muscle?
The external jugular vein crosses perpendicularly the superficial surface of the sternocleidomastoid muscle directly under the platysma muscle. The anterior jugular descends near the median line. The posterior auricular joints the retromandibular to form the external jugular. The internal jugular runs in the carotid sheath deep to the sternocleidomastoid muscle.
Retromandibular
Anterior jugular
Posterior auricular
External jugular