Which of the following muscles is classified as an extensor of the wrist and hand?

• A. Flexor carpi ulnaris
• B. Palmaris longus
• C. Extensor carpi radialis longus
• D. Flexor digitorum profundus

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the classification of muscles based on their function. Extensor muscles are responsible for increasing the angle between body parts, such as extending the wrist or fingers, while flexor muscles decrease the angle, such as flexing the wrist or fingers.
2. Step 2: Review the names and functions of the muscles listed in the problem. For example, 'Flexor carpi ulnaris' and 'Flexor digitorum profundus' are flexor muscles, meaning they are involved in bending the wrist or fingers. 'Palmaris longus' is also a flexor muscle that assists in wrist flexion.
3. Step 3: Identify the muscle that is classified as an extensor. The 'Extensor carpi radialis longus' is an extensor muscle, meaning it is responsible for extending the wrist and hand.
4. Step 4: Recall the anatomical location and action of the 'Extensor carpi radialis longus.' This muscle is located on the posterior side of the forearm and works to extend and abduct the wrist.
5. Step 5: Confirm the correct answer by matching the function of the muscle ('Extensor carpi radialis longus') with the classification provided in the question, ensuring it aligns with the definition of an extensor muscle.