Upper Limb Anatomy

Upper Limb Anatomy Study Notes

Introduction

  • Instructor: Dr. Tina Chiarelli
  • Institution: University of Central Florida, College of Medicine

Surface Anatomy of the Upper Limb

  • 1st Digit (Thumb)

    • Palm
    • Muscles:
    • Pectoralis major
    • Biceps brachii
    • Veins:
    • Basilic vein
    • Cephalic vein (in deltopectoral groove)
    • Bones:
    • Clavicle
    • Triceps brachii, lateral head
    • Styloid process of radius
    • Tendons:
    • Extensor carpi radialis longus
    • Brachioradialis
    • Flexor carpi ulnaris
    • Flexor carpi radialis
    • Fleshy Elements:
    • Hypothenar eminence
    • Thenar eminence
    • Palmer venous network

  • 5th Digit (Little Finger)

  • Surface Anatomy Overview:

    • Illustrated images of the right and left limbs, showing musculature and vascular structures.

Anatomical Structures

Scapula, Clavicle, and Humerus
  • Scapula Overview:
    • Key Landmarks:
    • Acromion
    • Coracoid process
    • Glenoid cavity
    • Superior angle
    • Inferior angle
    • Medial border
    • Lateral border
  • Clavicle Overview:
    • Parts:
    • Sternal (medial) end
    • Acromial (lateral) end
    • Features:
    • Trapezoid line
    • Conoid tubercle
    • Impression for costoclavicular ligament
  • Humerus Overview:
    • Key Features:
    • Greater and lesser tubercles, intertubercular sulcus
    • Anatomical neck and deltoid tuberosity
    • Epicondyles (medial and lateral)
    • Radial fossa, Olecranon fossa, Capitulum, and Trochlea
  • Elbow Articulations:
    • Humeroulnar and Humeroradial joints.

Fractures and Injuries

Common Fractures of the Humerus
  • Surgical neck fractures: may injure the Axillary nerve.
  • Middle shaft fractures: often injure the radial nerve resulting in wrist drop.
  • Distal humerus fractures: can injure the median nerve.
  • Medial epicondyle fractures: related to ulnar nerve injury.
  • Additional potential injuries include traumatic separation of the proximal epiphysis (common in youth) and shoulder joint dislocation.
Shoulder Joints
  • Types of Joints:
    • Acromioclavicular joint
    • Glenohumeral joint
    • Sternoclavicular joint
  • Ligaments Associated:
    • Coracohumeral ligament
    • Acromioclavicular ligament
    • Coracoacromial ligament

Muscle Anatomy of the Shoulder Region

Key Muscles
  • Trapezius:
    • Origin: Occipital bone, Spinous processes C1-C7 and T5-T12
    • Insertion: Clavicle, Acromion, and Scapular spine
    • Action: Draws scapula upward, medially downward; stabilizes scapula.
  • Deltoid:
    • Parts: Anterior, Middle, Posterior
    • Innervation: Axillary Nerve (C5-C6)
    • Action: Abducts arm, flexes and extends.
  • Latissimus Dorsi:
    • Origin: Spinous processes T7-T12, iliac crest
    • Insertion: Crest of lesser tuberosity of humerus
    • Action: Adduction, internal rotation, extension.

Brachial Plexus

  • Components:
    • Major Nerve Branches: Musculocutaneous, Axillary, Median, Radial, Ulnar
  • Innervation Patterns:
    • Musculocutaneous nerve: flexion at shoulder/elbow
    • Axillary nerve: shoulder rotation and arm abduction
    • Median nerve: forearm and hand movement
    • Radial nerve: upper limb movement
    • Ulnar nerve: fine motor control in hand

Vascular Contributions

Major Arteries
  • Subclavian Artery Branches:
    • Vertebral, Thyrocervical trunk, Costocervical trunk, Axillary artery, Brachial artery,
    • Radial and Ulnar arteries, Deep and Superficial palmar arches.

Carpal Anatomy

Carpal Bones
  • List of Carpal Bones: Scaphoid, Lunate, Triquetrum, Pisiform, Trapezium, Trapezoid, Capitate, Hamate.
  • Most Common Fracture: Scaphoid fractures at the waist which can affect blood supply.
Carpal Tunnel
  • Formed by the flexor retinaculum over the carpal bones.
  • Conditions: Carpal Tunnel Syndrome due to compression of the median nerve.

Hand Musculature

Intrinsic Muscles
  • Divided into: Thenar, Hypothenar, and Midpalmar muscles.
  • Function: Fine movements of the fingers, overall coordination and grip.
Lumbrical and Interossei Muscles
  • Key actions include flexion at the metacarpophalangeal joints and extension at the interphalangeal joints.

Common Injuries and Conditions

Nerve Injuries
  • Radial Nerve Injury: Results in wrist drop and sensory loss.
  • Median Nerve Injury: Results in paralysis of thumb muscles and possible hand of benediction appearance.
  • Ulnar Nerve Injury: Leads to claw hand characteristic.
Clinical Relevance
  • Importance of recognizing muscular and nerve injuries for rehabilitation and surgical interventions.
Conclusion
  • Understanding the complexities of the upper limb anatomy is critical for diagnosing and treating related medical conditions.