![]() In addition, the clavicle of each pectoral girdle is anchored to the axial skeleton by a single, highly mobile joint. The right and left pectoral girdles are not joined to each other, allowing each to operate independently. Both of these bones serve as important attachment sites for muscles that aid with movements of the shoulder and arm. Move your shoulder around and feel how the clavicle and scapula move together as a unit. By following along the clavicle, you can palpate out to the bony tip of the shoulder, and from there, you can move back across your posterior shoulder to follow the ridge of the scapula. This ridge extends out laterally, where it forms the bony tip of the shoulder and joins with the lateral end of the clavicle. The scapula is a flat, triangular-shaped bone with a prominent ridge running across its posterior surface. It is supported by the clavicle and articulates with the humerus (arm bone) to form the shoulder joint. The scapula (shoulder blade) lies on the posterior aspect of the shoulder. The appendicular skeleton consists of the pectoral and pelvic girdles, the limb bones, and the bones of the hands and feet.įigure 8.3 Pectoral Girdle The pectoral girdle consists of the clavicle and the scapula, which serve to attach the upper limb to the sternum of the axial skeleton. You can easily palpate, or feel with your fingers, the entire length of your clavicle.įigure 8.2 Axial and Appendicular Skeletons The axial skeleton forms the central axis of the body and consists of the skull, vertebral column, and thoracic cage. The lateral end of the clavicle articulates (joins) with the scapula just above the shoulder joint. It is attached on its medial end to the sternum of the thoracic cage, which is part of the axial skeleton. The clavicle (collarbone) is an S-shaped bone located on the anterior side of the shoulder. This consists of two bones, the scapula and clavicle ( Figure 8.3). The bones that attach each upper limb to the axial skeleton form the pectoral girdle (shoulder girdle). The appendicular skeleton includes all of the limb bones, plus the bones that unite each limb with the axial skeleton ( Figure 8.2). List the functions of the pectoral girdle.Describe the bones that form the pectoral girdle.The Pectoral Girdleīy the end of this section, you will be able to: The large range of upper limb movements, coupled with the ability to easily manipulate objects with our hands and opposable thumbs, has allowed humans to construct the modern world in which we live. Instead, our upper limbs are highly mobile and can be utilized for a wide variety of activities. In contrast, our upper limbs are not required for these functions. Thus, the bones of the lower limbs are adapted for weight-bearing support and stability, as well as for body locomotion via walking or running. ![]() The lower limb is attached to the vertebral column by the pelvic girdle.īecause of our upright stance, different functional demands are placed upon the upper and lower limbs. The bones of the shoulder region form the pectoral girdle, which anchors the upper limb to the thoracic cage of the axial skeleton. These bones are divided into two groups: the bones that are located within the limbs themselves, and the girdle bones that attach the limbs to the axial skeleton. Attached to this are the limbs, whose 126 bones constitute the appendicular skeleton. The adult axial skeleton consists of 80 bones that form the head and body trunk. Your skeleton provides the internal supporting structure of the body. Describe the embryonic formation and growth of the limb bones.Describe the bones of the lower limb, including the bones of the thigh, leg, ankle, and foot.Identify the features of the pelvis and explain how these differ between the adult male and female pelvis.Describe the bones of the upper limb, including the bones of the arm, forearm, wrist, and hand.Discuss the bones of the pectoral and pelvic girdles, and describe how these unite the limbs with the axial skeleton.(credit: Melissa Dooley/flickr)Īfter studying this chapter, you will be able to: Figure 8.1 Dancer The appendicular skeleton consists of the upper and lower limb bones, the bones of the hands and feet, and the bones that anchor the limbs to the axial skeleton.
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