Upper Limb Bones Anatomy

Bones of the Upper Limb

• Scapula (shoulder blade)
  • Forms the posterior wall of the thoracic cavity
  • Attaches to the humerus at the glenohumeral joint
• Humerus (upper arm bone)
  • Long bone of the upper arm
  • Connects the scapula to the forearm
• Radius and ulna (forearm bones)
  • Radius: lateral bone of the forearm
  • Ulna: medial bone of the forearm
• Carpals (wrist bones)
  • 8 bones that form the carpal tunnel
  • Connect the forearm to the hand
• Metacarpals (hand bones)
  • 5 bones that connect the carpals to the phalanges
• Phalanges (finger bones)
  • 14 bones that form the fingers and thumb

Joints of the Upper Limb

• Glenohumeral joint (shoulder joint)
  • Ball-and-socket joint between the scapula and humerus
• Elbow joint (humeroradial joint)
  • Hinge joint between the humerus and radius
• Radioulnar joint (forearm joint)
  • Pivot joint between the radius and ulna
• Wrist joint (radiocarpal joint)
  • Condylar joint between the radius and carpals
• Metacarpophalangeal joints (hand joints)
  • Condyloid joints between the metacarpals and phalanges
• Interphalangeal joints (finger joints)
  • Hinge joints between the phalanges

Muscles of the Upper Limb

• Deltoid muscle
  • Abducts the arm at the shoulder
• Biceps brachii muscle
  • Flexes the forearm at the elbow
• Triceps brachii muscle
  • Extends the forearm at the elbow
• Brachialis muscle
  • Flexes the forearm at the elbow
• Extensor muscles
  • Extend the wrist and fingers
• Flexor muscles
  • Flex the wrist and fingers

Nerves of the Upper Limb

• Brachial plexus
  • Network of nerves that innervate the upper limb
• Axillary nerve
  • Innervates the deltoid muscle
• Musculocutaneous nerve
  • Innervates the biceps brachii muscle
• Radial nerve
  • Innervates the extensor muscles of the forearm
• Median nerve
  • Innervates the flexor muscles of the forearm
• Ulnar nerve
  • Innervates the flexor muscles of the forearm and hand

Bones of the Upper Limb

• Scapula forms the posterior wall of the thoracic cavity and attaches to the humerus at the glenohumeral joint.
• Humerus is a long bone of the upper arm that connects the scapula to the forearm.
• Radius is the lateral bone of the forearm, while ulna is the medial bone of the forearm.
• Carpals are 8 bones that form the carpal tunnel and connect the forearm to the hand.
• Metacarpals are 5 bones that connect the carpals to the phalanges.
• Phalanges are 14 bones that form the fingers and thumb.

Joints of the Upper Limb

• Glenohumeral joint is a ball-and-socket joint between the scapula and humerus.
• Elbow joint is a hinge joint between the humerus and radius.
• Radioulnar joint is a pivot joint between the radius and ulna.
• Wrist joint is a condylar joint between the radius and carpals.
• Metacarpophalangeal joints are condyloid joints between the metacarpals and phalanges.
• Interphalangeal joints are hinge joints between the phalanges.

Muscles of the Upper Limb

• Deltoid muscle abducts the arm at the shoulder.
• Biceps brachii muscle flexes the forearm at the elbow.
• Triceps brachii muscle extends the forearm at the elbow.
• Brachialis muscle flexes the forearm at the elbow.
• Extensor muscles extend the wrist and fingers.
• Flexor muscles flex the wrist and fingers.

Nerves of the Upper Limb

• Brachial plexus is a network of nerves that innervate the upper limb.
• Axillary nerve innervates the deltoid muscle.
• Musculocutaneous nerve innervates the biceps brachii muscle.
• Radial nerve innervates the extensor muscles of the forearm.
• Median nerve innervates the flexor muscles of the forearm.
• Ulnar nerve innervates the flexor muscles of the forearm and hand.