Coxal Bones
Each coxal bone has the following three parts:
1) ilium. The ilium is the largest part of a coxal bone and flares outward to give the hip prominence. The margin of the ilium is called the iliac crest. Each ilium connects posteriorly with the sacrum at a sacroiliac joint.
2) ischium. The ischium is the most inferior part of a coxal bone and has a posterior region, the ischial tuberosity, that allows a person to sit. Near the junction of the ilium and ischium is the ischial spine,
which projects into the pelvic cavity. The distance between the ischial spines tells the size of the pelvic cavity. The greater sciatic notch is the site where blood vessels and the large sciatic nerve pass posteriorly into the lower leg.
pubis. The pubis is the anterior part of a coxal bone.
The two pubic bones join together at the pubic symphysis. Posterior to where the pubis and the ischium join together is a large opening, the obturator foramen, through which blood vessels and nerves pass anteriorly into the lower leg.
Where the three bones meet, there is a depression called the acetabulum, which receives the rounded head of the femur.
The pelvic girdle contains two coxal bones as well as sacrum and coccyx.
False and True Pelvises
The false pelvis is bounded laterally on the other the flared parts of the ilium. This space is much largethat of the true pelvis. The true pelvis is inferior to th pelvis and is the ring formed by the sacrum, lower ili-'chium, and pubic bones. The true pelvis is said to upper inlet and a lower outlet. The dimensions or outlets are important for females because the outlets be large enough to allow a baby to pass through during birth process.
Lower Limb (Leg)
The lower limb includes the bones of the thigh (femur), the lower leg (tibia and fibula), and those of the foot (tarsals, metatarsals, and phalanges).
Femur
The femur, or thighbone, is the longest and strongest bone in the body. Proximally, the femur has the following:
head, which fits into the acetabulum of the coxal bone;
greater and lesser trochanters, which provide a place of attachment for the muscles of the legs and buttocks;
linea aspera, a crest that serves as a place of attachment for several muscles.
Distally, the femur articulates with the patella (kneecap) and has lateral and medial condyles that articulate with the tibia.
Tibia
The tibia and fibula are the bones of the lower ego The tibia, or shinbone, is medial to the fibula and has the following:
medial and lateral condyles, which articulate with the femur;
tibial tuberosity, where the patellar (kneecap) ligaments attach;
anterior crest, commonly called the shin; medial malleolus, the bulge of the inner ankle.
Fibula
The fibula is lateral to the tibia and is more slender. It has a head that articulates with the tibia just below the lateral condyle and a distal lateral malleolus that forms the outer part of the ankle.
Foot
Each foot has an ankle, an instep, and five toes.
The ankle has seven tarsal bones; together, they are called the tarsus. Only one of the seven bones, the talus, can move freely where it joins the tibia and fibula. The largest of the ankle bones is the calcaneus, or heel bone. Along with the talus, it supports the weight of the body.
The instep has five elongated metatarsal bones. The distal ends of the metatarsals form the ball of the foot. Along with the tarsals, these bones form the arches of the foot (longitudinal and transverse), which give spring to a person's step. If the ligaments and tendons holding these bones together weaken, fallen arches or flat feet can result.Toes contain the phalanges. The big toe has only two phalanges, but the other toes have three each.
The lower limb contains the femur, the tibia, the fibula, and the bones of the foot (the tarsals, metatarsals, and phalanges).
