<P> The palmar surface is narrow and rough . At its upper part is a deep groove, running from above obliquely downward and medialward; it transmits the tendon of the Flexor carpi radialis, and is bounded laterally by an oblique ridge . This surface gives origin to the Opponens pollicis and to the Abductor and Flexor pollicis brevis; it also affords attachment to the transverse carpal ligament . </P> <P> The lateral surface is broad and rough, for the attachment of ligaments . </P> <P> The medial surface presents two facets; the upper, large and concave, articulates with the trapezoid bone; the lower, small and oval, with the base of the second metacarpal . </P> <P> The tubercle of trapezium is a tubercle found on the anterior surface of the bone . It is where sometimes abductor pollicis brevis muscle attaches . </P>

Which bone of the palm articulates with the thumb