MSA Appendicular Skeleton PDF

MUSCULOSKELETAL ANATOMY APPENDICULAR SKELETON  Human Appendicular Skeleton  The appendicular skeleton includes all the limb bones, plus the bones that unite each limb with the axial skeleton  the upper limbs function to grasp and manipulate objects  the lower limbs facilitat...

MUSCULOSKELETAL ANATOMY APPENDICULAR SKELETON  Human Appendicular Skeleton  The appendicular skeleton includes all the limb bones, plus the bones that unite each limb with the axial skeleton  the upper limbs function to grasp and manipulate objects  the lower limbs facilitate locomotion).  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  the pectoral girdle, or shoulder girdle, attaches the upper limbs to the body,  the pelvic girdle that attaches the lower limbs to the body  Pectoral Girdle (shoulder girdle)  The bones that attach each upper limb to the axial skeleton form the pectoral girdle (shoulder girdle).  The pectoral girdle consists of two bones, the scapula (shoulder blades)in the posterior and the clavicle (collarbone) in the anterior  Clavicle  The clavicle (collarbone) is an S-shaped bone located on the anterior side of the shoulder.  It is attached on its medial end to the sternum of the thoracic cage, which is part of the axial skeleton. The lateral end of the clavicle articulates (joins) with the scapula just above the shoulder joint.  The clavicle is the only long bone that lies in a horizontal position in the body  An articulation is any place at which two bones are joined.  The clavicles articulate with the sternum and the scapula.  Scapulae  lies on the posterior aspect of the shoulder  supported by the clavicle, which also  articulates with the humerus (arm bone) to form the shoulder joint. The scapula is a  flat, triangular-shaped bone  with a prominent ridge running across its posterior surface and extending out laterally, forming the bony tip of the shoulder and joining with the lateral end of the clavicle  This ridge, called the spine is a bony protrusion that facilitates a broad area of attachment for muscles to bone. The Upper Limb  The upper limb contains 30 bones in three regions: the arm (shoulder to elbow), the forearm (ulna and radius), and the wrist and hand  Upper Limbs  Our upper limbs are highly mobile and can be utilized for a wide variety of activities. 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.  Humerus The humerus is the largest and longest bone of the upper limb and the only bone of the arm. It articulates with the scapula at the shoulder and with the forearm at the elbow.  Forearm The forearm extends from the elbow to the wrist and consists of the ulna and the radius.  The radius is located along the lateral (thumb) side of the forearm The ulna is located on the medial aspect (pinky side) of the forearm. It is longer than the radius. Both articulate with the humerus at the elbow. Both articulate with the carpal bones and with each other  The Hand The hand includes the eight bones of the carpus (wrist), the five bones of the metacarpus (palm) the 14 bones of the phalanges(digits). Each digit consists of three phalanges, except for the thumb, when present, which has only two. The Pelvic Girdle  attaches the lower limbs to the axial skeleton.  responsible for bearing the weight of the body and for locomotion  securely attached to the axial skeleton by strong ligaments  has deep sockets with robust ligaments to securely attach the femur to the body.  strengthened by two large hip bones. In adults, c  the hip bones, or coxal bones, are formed by the fusion Pelvic of three pairs of bones: the ilium, ischium, and pubis. Girdle The pelvis joins together in the anterior of the body at a joint called the pubic symphysis and articulates with the bones of the sacrum at the posterior of the body. The female pelvis is slightly different from the male pelvis. Over generations of evolution, females with a wider pubic angle and larger diameter pelvic canal reproduced more successfully. Therefore, their offspring also had pelvic anatomy that enabled successful childbirth The Lower Limb consists of the thigh, the leg, and the foot. femur (thigh bone) patella (kneecap) tibia and fibula (leg bones) tarsals (bones of the ankle) metatarsals and phalanges (bones of the foot) (Figure 5).  The Lower Limb  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 bones of the lower limbs are thicker and stronger than the bones of the upper limbs because of the need to support the entire weight of the body and the resulting forces from locomotion. In addition to evolutionary fitness, the bones of an individual will respond to forces exerted upon them. The Femur The femur, or thighbone, is the longest, heaviest, and strongest bone in the body. The femur and pelvis form the hip joint at the proximal end. At the distal end, the femur, tibia, and patella form the knee joint. The Patella The patella, or kneecap, is a triangular bone that lies anterior to the knee joint. The patella is embedded in the tendon of the femoral extensors (quadriceps). It improves knee extension by reducing friction. The Tibia The tibia, or shinbone, is a large bone of the leg that is located directly below the knee. Articulates with the femur at its proximal end, with the fibula and the tarsal bones at its distal end. The second largest bone in the human body and Responsible for transmitting the weight of the body from the femur to the foot. The Fibula The fibula, or calf bone, parallels and articulates with the tibia. does not articulate with the femur does not bear weight. acts as a site for muscle attachment forms the lateral part of the ankle joint. Ankle and Foot The tarsals are the seven bones of the ankle. The ankle transmits the weight of the body from the tibia and the fibula to the foot. The metatarsals are the five bones of the foot. The phalanges are the 14 bones of the toes. Each toe consists of three phalanges, except for the big toe that has only two THE END !!