QuestionSBA
QuestionChoice
The arrow is pointing to one of the muscles of the thumb. This muscle seems to extend from the posterior surface of the arm to insert onto the distal phalanx of the thumb. This is the extensor pollicis longus. The anatomical snuffbox is a triangular depression located on the lateral aspect of the wrist. Its borders are defined as follows:

* Medial border: the extensor pollicis longus tendon
* Lateral border: the abductor pollicis longus and extensor pollicis brevis tendons
* Floor: the scaphoid and trapezium bones, along with the radial artery that runs through it
10041226
a
Extensor pollicis longus
QuestionChoice
The extensor pollicis brevis inserts onto the base of the proximal phalanx. The tendon of this muscle inserst onto the distal phalanx of the thumb and is therefore the extensor pollicis longus.
10041227
b
Extensor pollicis brevis
QuestionChoice
The extensor indicis extends to insert onto the extensor hood of the index finger. The muscle indicated by the arrow inserts onto the distal phalanx of the thumb and is therefore the extensor pollicis longus.
10041229
d
Extensor indicis
QuestionChoice
The arrow is pointing to one of the posterior forearm muscles. The abductor pollicis brevis is one of the thenar muscles of the hand.
10041230
e
Abductor pollicis brevis
QuestionChoice
he abductor pollicis longus is a muscle of the thumb that forms the radial border of the anatomical snuffbox, alongside the extensor pollicis brevis. It is located laterally to the extensor pollicis longus, helping in thumb abduction at the carpometacarpal joint.
10041228
c
Abductor pollicis longus
Concept
Chapter
2693
6275
Anatomical snuffbox
Topic
258
Upper Limb Anatomy
20544
Picture
3143
148 - Anatomical snuffbox (extensor pollicis long).png
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ozgCCwJDawErWlJ4Ro939Wk=
Topic
258
Upper Limb Anatomy
What is the name of the muscle indicated by the blue arrow.
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a