 This video will cover part two of the ependicular skeleton. As we go, we'll cover the following objective, list and describe the bones of the pectoral girdle and lower limbs. Here we see the pelvic girdle, where the lower limb attaches to the axial skeleton. The pelvic girdle is formed by the coxal bones. There are two coxal bones, left and right coxal bones, that articulate with the sacrum, here at the sacroiliac joint, and articulate with each other at the pubic synthesis, and articulate with the femur to form the hip joint at the acetabulum. Acetabulum literally translates as vinegar cup, and this is a smooth cup shape that articulates with the head of the femur, forming the hip joint. There are three bones that fuse together in order to form each coxal bone. The ilium is the flat superior and lateral region. So here I'll outline the ilium. So the superior region that I'm shading in green is the ilium, and then down here in red, I'll show the pubis, and then the ischium, I'll show in blue. The ischium is posterior and inferior. The pubis is anterior and inferior. And the pubis is where the pubic synthesis is formed between the left and the right coxal bones, the left and the right pubic bones articulate forming the pubic synthesis, a pad of fibrocartilage on the anterior midline of the coxal bone. And so we can see here the iliac crest. The iliac crest is this ridge of bone on the superior where you would rest your hands on your hip. If you were to rest your hands on your hip, they would be resting on the iliac crest, which is the origin for the internal abdominal oblique muscle and the insertion for the external abdominal oblique muscle. These oblique muscles are muscles that perform flexion and rotation of the vertebral column. And we can also see here the iliac fossa. So the iliac fossa is the anterior surface. So this illustration shows the iliac fossa, the smooth anterior surface. And this serves as the origin for a muscle, the iliacus muscle, which is an important muscle for flexion of the hip to move the femur at the hip. There's an anterior superior iliac spine, which is the edge of the iliac crest on the anterior. And there's a posterior superior iliac spine, the edge of the iliac crest on the posterior. The anterior superior iliac spine is the origin of the sartorius muscle, a muscle that's important for rotating the hip laterally and other motion. It contributes to deflecting the knee and what we call abduction of the hip, pulling the femur laterally. Then there's an anterior inferior iliac spine located just inferior to the anterior superior iliac spine. This is the anterior inferior iliac spine, also an origin for a muscle of the rectus femoris, a muscle in the quadriceps femoris group that extends the knee as its origin at the anterior inferior iliac spine. Similarly, there's a posterior inferior iliac spine, the posterior inferior iliac spine. The greater sciatic notch is a large curve on the posterior, where the ilium meets the ischium, the greater sciatic notch gets its name from the sciatic nerve, the largest nerve in the body, which travels along the greater sciatic notch. There is also a lesser sciatic notch that is part of the ischium. The lesser sciatic notch is located inferior to the ischial spine. Here we see the greater notch, and let's switch over to using an orange color for the ischium. The lesser sciatic notch just inferior to the ischial spine. We can see the large foramen, the obturator foramen, is located between the ischium and the pubis. The obturator foramen is the origin for muscles called the obturator muscles that assist with lateral rotation and abduction of the hip. The spine of the ischium serves as the inferior border of the greater sciatic notch and the superior border of the lesser sciatic notch. And then there is an ischial tuberosity located here inferior to the lesser sciatic notch. The ischial tuberosity is a rough projection of bone on the posterior of the ischium along the inferior and posterior, which serves as an origin for hamstrings, muscles that flex the knee, such as biceps femoris longhand, and the ischial biceps femoris longhand. Remember, a ramus projects off from the body at an angle, so the ischial body is the majority of the ischium on the posterior, and the ischial ramus is this projection of bone that meets the pubis. So the ischial ramus extends along the inferior, extends as a projection of bone anterior in order to articulate with the inferior ramus of the pubic. So the inferior ramus of the pubis is this part that meets with the ischio ramus at the we can call it altogether collectively the ischio pubic ramus. There's also a superior ramus of the pubis. The superior ramus is located superior to the obturator for raiment and connects to the ilium and then here we see the pubic tubercle. The pubic tubercle is a rough projection of bone located just superior to the surface of the pubic symphysis. So here we can see the articular surface of the pubis that forms the pubic symphysis and tubercle just superior to that. Here we can see the pubic angle or the sub pubic angle. This is the angle formed between the inferior pubic ramus of the left and right. And usually in men the sub pubic angle is less than 90 degrees. So we can see here whereas it'll be greater than 90 degrees in women. And this is one feature that can be used to distinguish between the pelvis of a male or female. Another feature is that the pelvic brim that we see here, this opening of the pelvis is much larger in the female and the ilium is much broader whereas in men the ilium is narrower and taller. The cue angle is another feature that's different between the female and male pelvis because the angle of the acetabulum points further inferior in men and more lateral in women. The cue angle is larger. This angle between the straight line up from the tibia and the line parallel with the diaphysis of the femur. This angle here is larger in women because the wider pelvis. Here we see the articulation between the coxal bone and the femur, the hip. So the femur is the largest and longest long bone located in the femoral region in the thigh. There's a long diaphysis called the body or the shaft and the articular surface of the epiphysis is the femoral head at the proximal end. So the head of the femur is the articular surface at the proximal end that fits into the acetabulum of the coxal bone. The neck is the narrow region that connects between the head and the rest of the epiphysis. You see here the greater trochanter is a large rough projection of bone on the lateral side of the proximal epiphysis. The greater trochanter is the insertion for muscles like the gluteus medius and piriformis, muscles that abduct the femur, that is pull the femur away from the midline. There's also a lesser trochanter, which is a rough projection on the medial side on the posterior here. We can see the lesser trochanter. The lesser trochanter is also an insertion for muscles. For example, the iliacus and psoas or the iliosoas muscle group, muscles that flex the hip insert here onto the lesser trochanter. The intertrochanteric crest is a ridge of bone on the posterior connecting between the greater and lesser trochanter. Then on the anterior there's an intertrochanteric line. Intertrochanteric line is much more subtle than the intertrochanteric crest. Here we see the linea aspera, a ridge of bone on the posterior, a straight ridge of bone on the posterior, literally translated linea aspera means rough line. This rough surface of bone provides origin for the biceps femoris short head of the quadriceps muscle group that flexes the knee and also insertion for the adductor magnus muscle that pulls the femur towards the midline. The femur has medial and lateral epicondyles which are ridges of bone located just proximal to the articular surface, the smooth articular surface known as the condyle. There are both lateral and medial condyles at the distal epithesis of the femur articulating with the tibia. You can see that the distal epithesis of the femur also articulates with the patella and has a flat patella surface, a smooth surface on the anterior of the distal epithesis that articulates with the patella. There's an intercondylar fossa, a smooth deep indentation between the medial and lateral condyles and there's also a ridge of bone called the gluteal tuberosity on the femur. The gluteal tuberosity is on the posterior just distal to the greater trochanter here and gluteal tuberosity is a rough projection where the gluteus maximus inserts. Here we see an illustration of the tibia and fibula. The tibia is the large long bone located in the medial curle region in the medial leg. There are medial and lateral condyles, smooth articular surfaces of the tibia that articulate with the femoral condyles and then there is an intercondylar eminence between the medial and lateral condyles. This is the intercondylar eminence. The anterior crest or anterior margin of the tibia, also known as the anterior border is the ridge on the anterior surface of the diaphysis and just proximal to the anterior border here we see the tibial tuberosity. Tibial tuberosity is this rough region of bone at the metaphysis where the epiphysis and diaphysis meet at the proximal end of the tibia. The tibial tuberosity serves as the point of insertion for the pateller tendon or the pateller ligament. So the pateller tendon is insertion of the quadriceps. The quadriceps insert onto the patella as the quadriceps tendon and then the pateller ligament connects from the patella down to the tibial tuberosity in order to extend the knee. At the distal epiphysis of the tibia there are the malleolus, medial malleolus is an extension that helps to stabilize the ankle joint. Malleolus literally means hammer but the medial malleolus helps to prevent the talus one of the tarsal bones from sliding across the tibia. So the lateral long bone in the leg in the corral region is the fibula. The fibula has a lateral malleolus that also helps to stabilize the ankle joint and this is the distal epiphysis of the fibula whereas the proximal epiphysis of the fibula is the head of the fibula. Here we see an illustration of the bones of the foot. Tarsals are short bones found in the ankle and the posterior pedal region. Here we can see the talus articulates with the tibia to form the ankle joint. The talus is the second largest of the tarsal bones and the talus articulates with the largest tarsal bone the calcaneus. The calcaneus forms the heel and the calcaneus is also the insertion for muscles in the sural region the gastrocnemius insolius muscles that perform an action called plantar flexion which pushes the foot towards the ground and so the tendon that inserts onto the calcaneus is known as the calcaneal tendon or more commonly the achilles tendon. Next we can see here the cuboid. So the cuboid is the large lateral tarsal bone that articulates with metatarsals number five and four. So here we can see the fifth metatarsal. The metatarsals are numbered one through five from medial to lateral and so it's the opposite direction as the numbering of the metacarpals. The peal digits are numbered from the big toe which is medial the halux is medial as number one and the small toe is number five and so the two lateral toes the metacarpals of four and five articulate directly with the cuboid then there's a navicular which articulates with the cuboid as well as the talus here and the navicular then articulates with the cuneiform bones on the medial side so the navicular is medial and the cuboid is lateral and the cuboid articulates directly with the metatarsals whereas the navicular articulates with the cuneiforms there's a medial cuneiform articulating with the first metatarsal an intermediate cuneiform articulating with the second metatarsal and a lateral cuneiform articulating with the third metatarsal here and also articulates here with the cuboid then the phalanges there's just like in the manual digits there's proximal middle and distal for two through five and the halux the big toe only has a distal and proximal phalange