Final answer:
The seven superficial posterior forearm muscles include the extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, extensor carpi ulnaris, typically the anconeus, and brachioradialis. These muscles originate on the humerus and are involved in extending the wrist and fingers, coordinating movement through associated nerves and blood vessels.
Step-by-step explanation:
Superficial Muscles of the Posterior Forearm
The superficial posterior compartment of the forearm contains several muscles that are primarily responsible for the extension of the wrist and fingers. The seven listed muscles originating on the humerus are the extensor carpi radialis longus, extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris. However, only five muscles have been listed.
Typically, the superficial layer includes the anconeus and brachioradialis, if considering all seven muscles in some anatomical variants, which makes up the seven superficial muscles frequently referred to in anatomy descriptions.
These muscles are also associated with various blood vessels and nerves that supply them, allowing for coordinated movement of the forearm, wrist, and fingers. The tendons of these muscles pass under the superior extensor retinaculum, which is a band of fibrous tissue that helps to hold the tendons in place as they cross the wrist joint.