The upper limbs, commonly called the arms, consist of three parts: the shoulder, upper arm, and forearm. These structures contain a series of bones that give shape and support to the regional muscles, allowing them to perform various movements. Arm Bones
The shoulder region allows the union of the upper limb to the trunk. There are two bones, the scapula and the clavicle, which also surround the upper part of the humerus, which corresponds to the bone located in the arm.
Clavicle. The clavicle is an elongated bone, with two curvatures that give it a shape similar to the letter “S”. This bone is located in the anterior part of the shoulder and in the chest. It is connected by their front part to the sternum, a bone on the front of the chest and posterior to scapulae, forming the joint acromioclavicular. This joint allows you to perform lifting movements of the arm above the head. Arm Bones
Shoulder blade. Also known as a shoulder blade. This bone is located in the posterior part of the shoulder, it is located over the ribs in such a way that it can slide over them, in its anterior part it articulates with the clavicle through an extension called the acromion. On its outside, it contains a depression called the glenoid cavity through which it articulates with the head of the humerus, forming the glenohumeral joint, which allows for flexion, extension and rotation of the arm.
The arm is the part of the upper limb located between the shoulder and the elbow. Arm Bones
This structure contains a single bone: the humerus, this is the longest bone in the upper limb. Its upper part is voluminous and is called the head of the humerus, which joins the scapula forming the glenohumeral joint. Its lower part has two voluminous structures, one on each side, with which it articulates with the ulna and radius, thus forming the elbow joint.
The forearm is the lower part of the upper limb, it is located between the elbow and the wrist .
The forearm contains two bones: the ulna, also called the ulna, and the radius. These join at the top of the humerus, at the bottom it articulates with the bones that form the wrist, known as the carpal bones.
The presence of these two bones enables a moving hand rotation making the palm go forward (supination) and back (pronation). Arm Bones
The hand is a complex structure made up of 27 bones distributed as follows:
Carpus. It corresponds to the wrist and contains 8 bones distributed in two rows.
Metacarpus. It contains 5 bones called metacarpals.
Fingers. There are small bones called phalanges. The index, middle and little ring fingers have 3 phalanges while the thumb has just two, for a total of 14 phalanges in each hand. Arm Bones