The major nerves in the hand are the ulnar nerve, radial nerve, and median nerve. These nerves originate at the shoulder and travel down the arm to the hand, controlling various functions such as movement and sensation.
Understanding the Major Nerves in the Hand
Ulnar Nerve
- Origin: Starts at the shoulder.
- Path: Travels down the arm to the hand.
- Function: Controls muscles in the forearm and hand, provides sensation to the little finger and half of the ring finger.
Radial Nerve
- Origin: Begins at the shoulder.
- Path: Extends down the arm to the hand.
- Function: Controls muscles in the arm and forearm that extend the wrist, fingers, and thumb; provides sensation to the back of the hand.
Median Nerve
- Origin: Originates at the shoulder.
- Path: Runs down the arm through the carpal tunnel in the wrist to the hand.
- Function: Controls muscles involved in the fine movements of the thumb and provides sensation to the thumb, index finger, middle finger, and half of the ring finger.
Summary Table of Major Nerves
| Nerve | Origin | Path | Function |
|---|---|---|---|
| Ulnar Nerve | Shoulder | Down the arm to the hand | Controls forearm and hand muscles; sensation to little finger and half of the ring finger. |
| Radial Nerve | Shoulder | Down the arm to the hand | Controls arm and forearm muscles for wrist and finger extension; sensation to the back of the hand. |
| Median Nerve | Shoulder | Down the arm to the hand | Controls thumb movement muscles; sensation to thumb, index, middle, and half of the ring finger. |
Key Functions and Examples
Motor Functions
- Ulnar Nerve: Enables movements such as gripping objects tightly and making a fist.
- Example: Holding a pen or squeezing a stress ball.
- Radial Nerve: Allows extension of the wrist and fingers.
- Example: Waving goodbye or lifting the hand upward.
- Median Nerve: Facilitates precise movements of the thumb and fingers.
- Example: Picking up small objects or typing on a keyboard.
Sensory Functions
- Ulnar Nerve: Provides sensation to the little finger and half of the ring finger.
- Radial Nerve: Supplies sensation to the back of the hand and the thumb side.
- Median Nerve: Delivers sensation to the thumb, index finger, middle finger, and half of the ring finger.
