<prompt> Which tendon is frequently absent in the upper limb?Flexor carpi ulnarisFlexor digitorum profundusExtensor carpi radialis brevisPalmaris longus  <response>: The palmaris longus may not always be present. It has a sho belly and long tendon. It originates from the medial epicondyle of the humerus. Distally, it passes over the flexor retinaculum with which its fibres mingle and is attached to the palmar aponeurosis. Reference: Clinical Anatomy for students, a problem-solving approach, Neeta v Kulkarni, 2nd edition, page no140 