Skeletal system: Lower Appendages Learning Target #8

Pelvic Girdle Functions: Bears the weight of the upper body Protection of the reproductive organs, urinary bladder, and part of the large intestine

Bones of the Pelvic Girdle Each hip (coxal) bone is made of 3 bones fused together: Ilium: Connects to the sacrum at the sacroiliac joint. Upper edge of the bone is called the iliac crest, which is a common site of bone marrow extractions Sacroiliac joint Iliac crest Ilium Ilium

Bones of the Pelvic Girdle Ischium: Known as the “sit down” bone because the ischial tuberosity receives the body weight when a person is seated. The ischial spine is important in pregnant women because it narrows the outlet of the pelvis through which the baby passes during the birthing process. Ischial spine Ischium

Bones of the Pelvic Girdle Pubis Most anterior part of the coxal bone Fuses with the ischium posteriorly to form the obturator foramen, which allow blood vessels and nerves to travel to the legs. The pubic bones of each hip fuse together at a joint called the pubic symphysis. Obturator foramen Pubic symphysis Pubis

Bones of the Pelvic Girdle The ilium, ischium, and pubis fuse at the acetabulum – the ball-and-socket joint that receives the head of the femur. Acetabulum

Male vs. Female Pelvis Oval-shaped Bones are heavier and more dense Longer, more curved sacrum Circular-shaped Bones are lighter and thinner Shorter, less curved sacrum Ischial spines are shorter and further apart, making the inlet larger

Male vs. Female Pelvis Male Pelvis Female Pelvis

Bones of the Leg Head of the femur Femur: (thigh bone) strongest, heaviest bone in the body. Greater and lesser trochanters – site of muscle attachment (quads, hamstring, gluteal, hip, etc.) Head of the femur – fits into the acetabulum of the pelvis Patellar surface – surface that forms a joint with the patella (kneecap) Greater trochanter Lesser trochanter Patellar surface

Femur and Acetabulum

Bones of the Leg Tibia: (shinbone) larger and more medial than the fibula. Tibial tuberosity – roughened area on the anterior surface where the patellar ligaments attach. Medial malleolus – forms the inner “bulge” of the ankle Fibula: (calf bone) thin and more lateral than the tibia, has NO contact with the knee joint Lateral malleolus – forms the outer “bulge” of the ankle

Bones of the Leg Tibial tuberosity Lateral malleolus Medial malleolus

Bones of the Leg Patella: (kneecap) covers and protects the knee joint

Bones of the Leg Tarsals: form the posterior half of the foot Calcaneous – heel bone Talus – ankle bone Navicular – forms the arch of the foot with the metatarsals Metatarsals: bones of the sole of the foot Each toe has three phalanges, except the big toe, which only has two Phalanges: bones of the toes

Bones of the Leg Phalanges Metatarsals Navicular Tarsals Talus Calcaneus