Appendicular Skeleton Pelvic Girdle Thigh (Leg) (Lower) Leg Foot The lower appendages are attached to the axial skeleton via the pelvic girdle

© 2015 Pearson Education, Inc. Bones of the Pelvic Girdle Pelvic girdle  2 coxal bones + sacrum – Coxal bones are three pairs of fused bones 1.Ilium 2.Ischium 3.Pubis Bony pelvis  2 coxal bones + sacrum + coccyx

© 2015 Pearson Education, Inc. Function of the Pelvic Girdle protects several organs – Reproductive organs – Urinary bladder – Part of the large intestine Bears weight of the upper body

Figure 5.26a The bony pelvis. Ilium Pubis Ischium (a) Coxal bone (or hip bone) Sacrum Coccyx Pubic arch Iliac crest Sacroiliac joint Pelvic brim Ischial spine Acetabulum Pubic symphysis Articulates with axial skeleton at the sacrum = sacroiliac joint

Figure 5.26b The bony pelvis. Ilium Iliac crest Anterior superior iliac spine Anterior inferior iliac spine Acetabulum Body of pubis Pubis Inferior pubic ramus Obturator foramen Ala Posterior superior iliac spine Posterior inferior iliac spine Greater sciatic notch Ischial body Ischial spine Ischial tuberosity Ischium Ischial ramus (b)

© 2015 Pearson Education, Inc. Gender Differences of the Pelvis The female’s pelvis: – Inlet is larger and more circular – Pelvis as a whole is shallower, and the bones are lighter and thinner – Ilia flare more laterally – Sacrum is shorter and less curved – Ischial spines are shorter and farther apart; thus, the outlet is larger – Pubic arch is more rounded because the angle of the pubic arch is greater

Figure 5.26c The bony pelvis. False pelvis Inlet of true pelvis Pelvic brim False pelvis Inlet of true pelvis Pelvic brim (c) Pubic arch (less than 90 ° ) Pubic arch (more than 90 ° )

© 2015 Pearson Education, Inc. Bones of the Lower Appendages Femur—thigh bone – heaviest, strongest bone in the body – Proximally, the head articulates with the acetabulum of the (hip) bone This creates a ball-and-socket joint – Distally, the lateral and medial condyles articulate with the tibia in the lower leg

Figure 5.27a Bones of the right thigh and leg. Neck Inter- trochanteric line Lesser trochanter (a) Lateral condyle Patellar surface Head

Figure 5.27b Bones of the right thigh and leg. Lesser trochanter Gluteal tuberosity Greater trochanter Inter- trochanteric crest (b) Lateral condyle Head Intercondylar fossa Medial condyle

© 2015 Pearson Education, Inc. Bones of the Lower Limbs 1.Tibia—shinbone; larger and medially oriented – Medial and lateral condyles articulate proximally with the femur to form the knee joint 2.Fibula—thin and sticklike; lateral to the tibia – Not part of the knee joint (Patella- a sesamoid (short) bone that lies anteriorly in the knee joint; called kneecap)

Figure 5.27c Bones of the right thigh and leg. Intercondylar eminence Lateral condyle Head Proximal tibiofibular joint Medial condyle Tibial tuberosity Interosseous membrane Anterior border Tibia Medial malleolus Distal tibiofibular joint Lateral malleolus (c) Fibula

© 2015 Pearson Education, Inc. Bones of the Foot Tarsals—Two largest tarsals Calcaneus (heel bone) Talus Metatarsals—form the sole of the foot Phalanges—form the toes – Big toe is the hallux – All have 3 bones; hallux has 2

Figure 5.28 Bones of the right foot, superior view. Medial cuneiform Tarsals: Phalanges: Metatarsals Tarsals: Intermediate cuneiform Navicular Talus Distal Middle Proximal Lateral cuneiform Cuboid Calcaneus

© 2015 Pearson Education, Inc. Arches of the Foot Bones of the foot are arranged to form three strong arches – Two longitudinal Medial and laterally located – One transverse

Figure 5.29 Arches of the foot. Medial longitudinal arch Transverse arch Lateral longitudinal arch