Editing Scaphoid bone (section)

== Structure ==
The scaphoid is situated between the [[Anatomical terms of location#Proximal and distal|proximal and distal]] rows of [[carpal bone]]s. It is located on the radial side of the wrist,<ref name="BEASLEY2003" />{{rp|176}} adjacent to the [[Radial styloid process|styloid process of the radius]].<ref name=":02">{{Cite book |last=Martini |first=Frederic |title=Human Anatomy |last2=Tallitsch |first2=Robert B. |last3=Nath |first3=Judi L. |publisher=Pearson |year=2017 |isbn=9780134320762 |edition=9th |pages=182}}</ref> It articulates with the [[radius (bone)|radius]], [[lunate bone|lunate]], [[trapezoid bone|trapezoid]], [[trapezium (bone)|trapezium]], and [[capitate]].<ref name=BEASLEY2003>{{cite book |last=Beasley |first=Robert W. | name-list-style = vanc |title=Beasley's Surgery of the Hand |year=2003 |publisher=Thieme |location=New York|isbn=978-1-282-95002-3|oclc=657589090}}</ref>{{rp|176}} Over 80% of the bone is covered in articular [[cartilage]].<ref name=EATHORNE2005 />

===Bone===
The palmar surface of the scaphoid is concave, and forming a distal [[tubercle]], giving attachment to the [[Flexor retinaculum of the hand|transverse carpal ligament]]. The proximal surface is triangular, smooth and convex.<ref name=EATHORNE2005>{{cite journal | vauthors = Eathorne SW | title = The wrist: clinical anatomy and physical examination--an update | journal = Primary Care | volume = 32 | issue = 1 | pages = 17–33 | date = March 2005 | pmid = 15831311 | doi = 10.1016/j.pop.2004.11.009 }}</ref> The lateral surface is narrow and gives attachment to the [[radial collateral ligament (wrist)|radial collateral ligament]]. The medial surface has two facets, a flattened semi-lunar facet articulating with the lunate bone, and an inferior concave facet, articulating alongside the lunate with the head of the capitate bone.<ref name="Gray-6b1-4" />

The dorsal surface of the bone is narrow, with a groove running the length of the bone and allowing [[ligament]]s to attach, and the surface facing the fingers (anatomically inferior) is smooth and convex, also triangular, and divided into two parts by a slight ridge.<ref name="Gray-6b1-4" />

===Blood supply===
It receives its blood supply primarily from lateral and distal branches of the [[radial artery]], via palmar and dorsal branches. These provide an "abundant" supply to middle and distal portions of the bone, but neglect the proximal portion, which relies on [[:wikt:retrograde|retrograde]] flow.<ref name=BEASLEY2003 />{{rp|189}} The dorsal branch supplies the majority of the middle and distal portions, with the palmar branch supplying only the distal third of the bone.<ref name=EATHORNE2005 />

===Variation===
The dorsal blood supply, particularly of the proximal portion, is highly variable.<ref name=BEASLEY2003 />{{rp|189}} Sometimes the fibers of the [[abductor pollicis brevis]] emerge from the tubercle.<ref name="Gray-6b1-4" />

===In animals===
In reptiles, birds, and amphibians, the scaphoid is instead commonly referred to as the '''''radiale''''' because of its articulation with the [[radius (bone)|radius]].