ANA 201-1

SCHOOL INFORMATION

  • Institution: Western Delta University

  • College: College of Applied Health Sciences

  • Course: Gross Anatomy of the Upper Limbs

  • Course Code: ANA 201

  • Department: Medical Laboratory Sciences and Nursing Science

  • Lecturer: Mr. Ohirhian, J.

INTRODUCTION TO THE UPPER LIMBS

The upper limb is anatomically divided into four distinct regions:

  1. Shoulder region

  2. Arm (brachium)

  3. Forearm (antebrachium)

  4. Hand (manus)

1. Shoulder Region

  • Components:
    a. Pectoral Region: Front of the chest.
    b. Axilla: Armpit area.
    c. Scapular Region: Back area around the scapula.

  • Bones of the Shoulder Girdle:

    • Clavicle

    • Scapula

  • The clavicle articulates with the axial skeleton at the sternoclavicular joint; the scapula is mobile and held in place by muscles.

  • The clavicle and scapula articulate at the acromioclavicular joint.

2. Arm/Brachium

  • Extends from the shoulder to the elbow (cubitus).

  • Bone: Humerus

  • Upper end of the humerus forms the shoulder joint with the scapula, allowing arm movement.

3. Forearm/Antebrachium

  • Extends from the elbow to the wrist.

  • Bones: Radius and Ulna

  • Upper ends of the radius and ulna articulate with the lower end of the humerus to form the elbow joint; lower ends connect with the carpal bones to form the wrist joint.

  • Joint Functions:

    • Elbow joint: Allows flexion and extension of the forearm.

    • Radioulnar joints: Allow for pronation and supination (rotational movements of the forearm).

    • In a mid-flexed elbow:

      • Supination: Palm faces upwards.

      • Pronation: Palm faces downwards.

4. Hand/Manus

  • Components:
    a. Wrist (Carpus): Composed of eight carpal bones arranged in two rows.
    b. Hand Proper (Metacarpus): Five metacarpal bones support the hand.
    c. Digits: Five fingers (thumb and four fingers); each finger has three phalanges while the thumb has two, totaling 14 phalanges.

  • Wrist Joint: Formed by carpal bones and the radius.

  • Metacarpophalangeal Joints: Between metacarpals and phalanges.

  • Interphalangeal Joints: Between phalanges.

  • Movements: Primarily at the wrist joint, including the thumb moving at the first carpometacarpal joint, enabling opposition.

CLAVICLE

  • The clavicle is a long, S-shaped bone that lies horizontally between the sternum and the acromial end of the scapula.

  • It acts as a brace for the shoulder and facilitates the transfer of weight from the upper limbs to the axial skeleton.

  • Injuries: Clavicular injuries can