Ulna & Radius Flashcards
What is the stabilizing bone of the forearm?
Ulna
The ulna is ____ and _____ than the radius
medial and longer
What are the two prominent projections of the ulna, and what do they form?
Olecranon (posteriorly) and coronoid process (anteriorly). They form the walls of the trochlear notch.
What is unique about the shaft of the Ulna?
is thick, but tapers, diminishing in diameter distally.
What is on the distal end of the ulna?
ulnar styloid process
The ____ does not articulate directly with the carpal bones; it is separated from the carpals by _______.
ULNA; fibrocartilaginous articular disc.
The radius is ____ and _____ than the ulna.
Lateral and shorter.
What does the proximal end of the radius consist of?
Cylindrical head, short neck, a projection from the medial surface, and the radial tuberosity.
The head of the radius is _____. Why?
concave; for articulation with the capitulum of the humerus.
The head of the radius articulates medially with what?
the radial notch of the ulna.
The lateral aspect of the radius terminates distally at the?
radial styloid process.
What is the difference between the radial and ulnar styloid process?
The radial styloid process is larger than the ulnar styloid process and extends farther distally.
What does the dorsal tubercle of the radius do?
Lies between two of the shallow grooves for passage of the tendons of forearm muscles and serves as a trochlea (pulley) for the tendon of the long extensor of the thumb.
