Anatomy of the Upper Limb

The upper limb consists of the shoulder girdle, arm, forearm, and hand.
Functionally divided into bones, muscles, blood vessels, nerves, and connective tissues.

Shoulder Girdle
- Clavicle (collarbone)
- Scapula (shoulder blade)
Arm
- Humerus (upper arm bone)
Forearm
- Radius (lateral bone, thumb side)
- Ulna (medial bone, pinky side)
Hand
- Carpals (wrist bones, 8 total)
- Metacarpals (hand bones, 5 total)
- Phalanges (finger bones, 14 total: 3 per finger, 2 per thumb)

Shoulder Joint: Ball-and-socket joint allowing a wide range of motion.
Elbow Joint: Hinge joint enabling flexion and extension.
Wrist Joint: Complex joint allowing flexion, extension, and limited rotation.

Shoulder Muscles
- Deltoid: Shoulder abduction
- Rotator cuff muscles: Stabilization of the shoulder joint.
Arm Muscles
- Biceps brachii: Flexion of the elbow and supination of the forearm.
- Triceps brachii: Extension of the elbow.
Forearm Muscles
- Flexors: Flexion of the wrist and fingers (anterior compartment).
- Extensors: Extension of the wrist and fingers (posterior compartment).
Hand Muscles
- Thenar muscles: Move the thumb.
- Hypothenar muscles: Move the little finger.
- Interossei: Abduct and adduct fingers.

Brachial Plexus: Network of nerves supplying the upper limb.
- Major branches include:
  - Musculocutaneous nerve: Innervates anterior arm.
  - Median nerve: Innervates forearm flexors and hand.
  - Ulnar nerve: Innervates intrinsic hand muscles.
  - Radial nerve: Innervates posterior arm and forearm.

The upper limb allows for a wide range of movements and precise manipulation, essential for daily activities and tool use.
Importance of stability and mobility in joint function, especially in the shoulder and wrist.

The upper limb is divided into four main sections: shoulder girdle, arm, forearm, and hand.
Composed of bones, muscles, blood vessels, nerves, and connective tissues for various functions.

Shoulder Girdle: Comprises the clavicle (collarbone) and scapula (shoulder blade).
Arm: Contains the humerus, the single bone of the upper arm.
Forearm: Features two bones:
- Radius: Positioned laterally, associated with the thumb side.
- Ulna: Positioned medially, associated with the pinky side.
Hand:
- Carpals: Eight wrist bones forming the wrist structure.
- Metacarpals: Five bones constituting the framework of the hand.
- Phalanges: Fourteen finger bones (three per finger, two per thumb).

Shoulder Joint: A ball-and-socket configuration promoting extensive movement.
Elbow Joint: Functions as a hinge joint, permitting flexion and extension.
Wrist Joint: Complex structure allowing for flexion, extension, and some rotational movement.

Shoulder Muscles:
- Deltoid: Primarily responsible for shoulder abduction.
- Rotator Cuff Muscles: Essential for shoulder stabilization during movement.
Arm Muscles:
- Biceps Brachii: Facilitates elbow flexion and forearm supination.
- Triceps Brachii: Responsible for elbow extension.
Forearm Muscles:
- Flexors: Control wrist and finger flexion (located in the anterior compartment).
- Extensors: Manage wrist and finger extension (located in the posterior compartment).
Hand Muscles:
- Thenar Muscles: Focus on thumb movement and functionality.
- Hypothenar Muscles: Specialize in movements of the little finger.
- Interossei: Aid in finger abduction and adduction.

Subclavian Artery: The primary artery providing blood to the entire upper limb.
Brachial Artery: Continuation from the subclavian artery, supplying the arm.
Radial and Ulnar Arteries: Supply regions of the forearm and hand, ensuring adequate blood flow.

Brachial Plexus: A network that supplies sensory and motor functions to the upper limb.
Major Nerve Branches:
- Musculocutaneous Nerve: Primarily innervates the anterior arm muscles.
- Median Nerve: Innervates forearm flexors and several hand muscles.
- Ulnar Nerve: Responsible for the innervation of intrinsic hand muscles.
- Radial Nerve: Innervates muscles of the posterior arm and forearm.

The upper limb's design allows for diverse movements and precise manipulations crucial for daily tasks and tool usage.
Stability and mobility are vital in joint function, particularly within the shoulder and wrist, enabling effective movement and control.