Anatomy of the Upper Limb Quiz

The upper limb, also known as the upper limb or the upper extremity, is a complex structure composed of bones, muscles, and joints that work together to allow for a wide range of movements. The upper limb extends from the shoulder joint proximally to the hand distally and consists of the arm, forearm, and hand.

Arm (Brachium)

The arm, or brachium, is the proximal part of the upper limb located above the elbow. It is composed of bones, muscles, and joints that work together to provide stability and support for the entire upper limb. The brachium is formed by the humerus bone, which is the largest bone in the arm and connects the shoulder joint to the elbow joint. The elbow joint is a complex synovial joint where the humerus articulates with the radius and ulna bones of the forearm.

Forearm

The forearm is the section of the upper limb between the elbow and the wrist. It is formed by the radius and ulna bones, which are connected by an interosseous membrane. The muscles of the forearm are divided into two compartments: the anterior flexor compartment and the posterior extensor compartment. The anterior compartment contains muscles that flex the hand at the wrist joint, while the posterior compartment contains muscles that extend the hand at the wrist joint. One important muscle in the forearm is the brachioradialis, which runs from the arm to the wrist and helps to flex the elbow.

Hand

The hand is the distal part of the upper limb below the wrist. It is composed of bones, muscles, and joints that work together to allow for fine motor movements and gripping. The hand is divided into four compartments: the thenar, hypothenar, adductor, and central palmar compartments. The thenar compartment contains muscles that move the thumb, while the hypothenar compartment contains muscles that move the small finger. The adductor compartment contains muscles that adduct the thumb, and the central palmar compartment contains short muscles that flex and extend the metacarpophalangeal and interphalangeal joints of the fingers.

Injuries to the upper limb can lead to a range of disabilities, including weakness, numbness, and loss of function. For example, Carpal Tunnel Syndrome is a common condition that causes compression of the median nerve in the wrist, leading to pain, numbness, and weakness in the hand. In severe cases, surgery may be necessary to release the compression and restore function.

In conclusion, the anatomy of the upper limb is a complex and fascinating system of bones, muscles, and joints that work together to allow for a wide range of movements. Understanding this anatomy is essential for medical professionals and researchers, as well as for anyone interested in the workings of the human body.