VIDEO
CONTENT
QUIZ
MATERIALS
Quick Facts
Shoulder Girdle
Arm
Forearm
Wrist
Hand
The upper limb is a marvel of human anatomy, granting us the ability to perform a wide range of complex movements. This intricate appendage is divided into several regions, each with its own unique structure and function. Understanding these regions is crucial for anyone studying or interested in human anatomy, from the shoulder down to the fingertips.
The Shoulder Girdle: The Foundation The shoulder girdle serves as the attachment point connecting the upper limb to the torso. This region comprises two main bones:
- The Clavicle (Collarbone): A slender, S-shaped bone that provides anterior support for the shoulder.
- The Scapula (Shoulder Blade): A flat, triangular bone with several important muscle attachments, it forms the back portion of the shoulder girdle.
The Arm: The Central Pillar The arm, or brachium, is the region between the shoulder and the elbow. It consists of a single, long bone:
- The Humerus: This is the largest bone in the upper limb, articulating with the scapula at the shoulder joint and the radius and ulna at the elbow.
The Forearm: The Link and Lever The forearm, or antebrachium, extends from the elbow to the wrist and comprises two parallel bones:
- The Radius: Located on the thumb side of the forearm, it is involved in the forearm’s rotation.
- The Ulna: The longer of the two bones, it forms a hinge joint with the humerus at the elbow.
The Wrist: The Connector The wrist, or carpus, is a complex region with eight small bones known as the carpal bones. They are arranged in two rows and allow for the wrist’s intricate movements.
The Hand: The Instrument of Instruments The hand, divided into three parts, is a versatile and dexterous tool:
- The Metacarpus (Palm): Comprising five metacarpal bones, it forms the palm’s structure.
- The Fingers (Digits): Consisting of phalanges, 14 in total for each hand, they provide the hand’s grasping function.
- The Thumb (Pollex): With two phalanges compared to the three in other fingers, it provides opposition, a unique movement enhancing manual dexterity.