The Appendicular Skeleton

The clavicle is a long b unrivaled, but it has no medullary cavity. The clavicle supports the scapula and arms, it protects chummyer structures (blood vessels, for example) in the upper chest, and it transmits impact from the arms to the axile skeleton. The scapula is attached to the thorax and vertebral column by muscles. The pectoralis girdles attach the upper extremities (limbs) to the axial skeleton and provide attachment sites for many a nonher(prenominal) muscles that move the upper limbs. The 2 pectoral girdles and the associated muscles year your get ups.The pectoral girdles be very flexible and allow the upper limbs a great buy of flexibility. They permit movement in many directions at the shoulder joint. The socket of the shoulder joint is small, shallow, and poorly reinforced with ligaments. This arrangement is good for flexibility, but it is not very unchanging. Shoulder dislocations are therefore fairly common. The UPPER LIMBS (extremities) (FIGS. 8. 4-8. 8) c omprise of 60 bones 30 bones per limb. These are the bones of the arms, wrists, and hands.They imply the HUMERUS, ULNA, RADIUS, CARPALS, METACARPALS, and PHALANGES. The PELVIC GIRDLE (hip girdle) (FIGS. 8. 9-8. 11 & TABLE 8. 1) attaches the lower extremities (limbs) to the axial skeleton, and it supports and protects the nonrational organs of the pelvic cavity. The pelvic girdle is a strong and stable support for the lower limbs. While the shoulder girdle moves somewhat freely and allows the arms a great deal of mobility, the pelvic girdle is secured to the axial skeleton by some of the strongest ligaments of the body.Its sockets, which articulate with the thigh bones, are deep and cup-like and are heavily reinforced with ligaments. Even though both the shoulder and hip joints are ball-and-socket joints, the thigh cannot move in its socket with the same detail of freedom as the arm can in the shoulder joint. tractableness in the hip joint is sacrificed for stability. The pelvic girdle consists of the 2 HIPBONES (coxal bones). from each one hipbone of a newborn baby consists of 3 bones the professionalILIUM, the inferior and anterior PUBIS, and the inferior and posterior ISCHIUM. Eventually these fuse into one COMPOSITE bone.The area where they all fuse is called the ACETABULUM, which serves as the socket for the femur. The PUBIS of the hipbones image anteriorly at the PUBIC SYMPHYSIS. The hipbones articulate posteriorly with the sacrum at the SACROILIAC JOINT. The 2 hipbones, with the sacrum and coccyx, form the basin-like structure called the PELVIS. The LOWER LIMBS (extremities) consists of 60 bones (FIG. 8. 12-8. 17) 30 bones per limb. These embarrass the FEMUR (thighbone), PATELLA (kneecap), FIBULA & TIBIA (lower leg), TARSALS (anklebones and heel bones), METATARSALS (feet), and PHALANGES (toes).