Appendicular Skeleton The Lower Limbs

The Lower Limbs – Pelvic Girdle Formed by the two coxal bones (a.k.a. ossa coxae) that form the hip bones Coxal bones are attached to the sacrum to form the bony pelvis The bony pelvis holds the entire weight of the upper body and protects the organs of the lower abdomen The pelvis is divided into two sections—false pelvis and true pelvis False pelvis is area between wings of hip True pelvis is open space between the bones, anterior to sacrum and coccyx

The Lower Limbs – Pelvic Girdle

The Lower Limbs – Pelvic Girdle Each hip bone is made by the fusion of three bones—ilium, ischium, and pubis Ilium is the largest bone of the coxa Connects to the alae of the sacrum Form the superior, winged section of hip bone and the superior part of the acetabulum Iliac crest is edge of the ilium that stretches from the anterior superior spine to the posterior superior spine

The Lower Limbs – Pelvic Girdle

The Lower Limbs – Pelvic Girdle The ischium is also called the “sitdown bone” Forms the most inferior part of the coxa Ischial tuberosity is roughened area of most inferior point that receives the body weight when sitting Ischial spine is a projection on the posterior side of the ischium, above the ischial tuberosity Greater sciatic notch is above the ischium, below the posterior inferior iliac spine that allows nerves and blood vessels to pass from the back of the pelvis to the thigh

The Lower Limbs – Pelvic Girdle

The Lower Limbs – Pelvic Girdle The pubis is the most anterior part of the pelvis The ramus of each pubic bone forms the anterior side of the obturator foramen (the ischial ramus forms the posterior), which allows blood vessels and nerves to pass into the anterior part of the thigh The pubic symphysis is the cartilaginous point of fusion for the pubic bones in the front The acetabulum is the socket formed by the three bones where the thigh bone articulates with the hip

The Lower Limbs – Pelvic Girdle

The Lower Limbs – Thigh Thigh consists of one bone—the femur—that is the heaviest, strongest bone in the body The proximal end of the femur includes a head, neck, and trochanters The head is rounded and fits deep into the acetabulum of the hip The neck is the constricted part of bone just inferior/lateral to the head The greater trochanter is a projection on the top of the bone for muscle attachment The less trochanter is a projection inferior to the neck that allows for muscle attachment

The Lower Limbs – Thigh The gluteal tuberosity is a ridge on the posterior that runs the length of the shaft and attaches to the gluteal muscles The distal end of the femur includes the lateral and medial condyles, separated by the intercondylar notch

The Lower Limbs – Thigh

The Lower Limbs – Leg The leg consists of two bones—the tibia and fibula The tibia and fibula are connected by an interosseous membrane The tibia is also called the shinbone Larger, more medial bone of the leg Articulates with femur at the medial and lateral condyles (separated by the intercondylar eminence) Tibial tuberosity is roughened surface on anterior side of tibia that serves as a point of attachment for the patellar ligament Anterior crest runs the length of the anterior side of the tibia Medial malleolus is process on distal, medial end of tibia that forms inner bulge of ankle

The Lower Limbs – Leg The fibula is the smaller, lateral bone of the leg Does not articulate with the femur Sticklike structure that forms joints with the tibia proximally and distally Lateral malleolus forms the outer part of the ankle

The Lower Limbs – Leg

The Lower Limbs – Foot Foot has three sections (like the hand) with the tarsals, metatarsals, and phalanges There are 7 tarsal bones that form the inner ankle and the heel 5 metatarsals form the sole of the foot 14 phalanges form the toes; labeled proximal, middle, and distal like the fingers Ligaments within the tarsals and metatarsals cause the arch of the foot (two longitudinal arches, 1 transverse arch)

The Lower Limbs – Foot