Wrist Extensor Zones EXPLAINED

The video tutorial explains the extensor tendon zones, focusing on the muscles in the posterior forearm whose tendons extend across the wrist into the hand. It covers the anatomy of the carpal tunnel, highlighting the differences between the flexor and extensor retinacula. The tutorial details the six extensor tendon zones, describing the tendons and their functions in each zone. It concludes with the functional importance of the extensor retinaculum in preventing bowstringing during wrist extension.

What is the primary function of the extensor retinaculum?

• To prevent bowstringing of tendons

• To divide tendons into zones

• To allow tendons to penetrate through

• To cover the tendons

Which tendons are found in the first extensor tendon zone?

• Extensor digiti minimi and extensor carpi ulnaris

• Extensor digitorum and extensor indicus

• Abductor pollicis longus and extensor pollicis brevis

• Extensor carpi radialis longus and brevis

What is the role of the abductor pollicis longus?

• To abduct the thumb

• To flex the thumb

• To adduct the thumb

• To extend the thumb

Which bone does the extensor pollicis longus tendon cross over after the wrist joint?

• Capitate

• Trapezoid

• Trapezium

• Hamate

What separates the second and third extensor tendon zones?

• Trapezium

• Hamate

• Capitate

• Listers tubercle

Which tendon is found in the fifth extensor tendon zone?

• Extensor carpi ulnaris

• Extensor digiti minimi

• Extensor indicus

• Extensor digitorum

Where is the extensor carpi ulnaris tendon located in relation to the triquetrum?

• Dorsal and lateral

• Dorsal and medial

• Ventral and lateral

• Ventral and medial