Overview
This lecture covers the anatomy of the forearm, wrist, and hand bones, highlighting their distinguishing features and key anatomical landmarks.
Bones of the Forearm
- The forearm contains two bones: the ulna and the radius.
- The ulna is identified by its scoop- or wrench-like structure at the top.
- The radius is recognizable by its knob-like head at one end.
Ulna: Key Structures
- The olecranon process is a prominent structure at the top of the ulna, fitting into the olecranon fossa of the humerus.
- The coronoid process fits into the coronoid fossa of the humerus.
- The trochlear notch is the scoop-shaped part that articulates with the trochlea of the humerus.
- The radial notch is the site on the ulna where the head of the radius rests.
- The styloid process is a pointed structure at the distal end of the ulna.
Radius: Key Structures
- The head of the radius is the knob-like structure at its proximal end.
- The radial tuberosity is a rough area for the attachment of the biceps brachii muscle.
- The styloid process of the radius is a pointed projection at the distal end.
Bones of the Wrist and Hand
- The carpal bones form the wrist.
- The metacarpals make up the middle part (palm) of the hand.
- The phalanges are the bones of the fingers: three in each finger and two in each thumb.
Key Terms & Definitions
- Ulna — inner forearm bone with a scoop-like upper end.
- Radius — outer forearm bone ending in a round "head."
- Olecranon process — projection at the upper end of the ulna; forms the elbow.
- Coronoid process — projection beneath the olecranon on the ulna.
- Trochlear notch — curved notch on the ulna that articulates with the humerus.
- Radial notch — small notch on the ulna for the head of the radius.
- Styloid process — pointed projection at the distal end of the ulna or radius.
- Radial tuberosity — rough area on the radius for biceps attachment.
- Carpals — eight bones forming the wrist.
- Metacarpals — five bones forming the palm of the hand.
- Phalanges — finger bones; three per finger, two in the thumb.
Action Items / Next Steps
- Review diagrams of the forearm, wrist, and hand bones.
- Memorize the locations and features of ulna and radius structures.
- Practice labeling the bones and key landmarks on skeletal images.