Human Anatomy - Zynoviy Myrchuk, Maryna Myrchuk 2007

Axial skeleton
Bones of the lower limb

The Pelvic Girdle consists of the hip bones, which are connected to the sacrum by means of the paired sacroiliac joints.

The hip bone is formed by three components: the ilium (posterosuperior part), the ischium (posteroinferior part), and the pubis (anterior part). These bones fuse together by Puberty. On their external surface, they form a spherical depression known as the acetabulum, which serves as the socket for the HEAD of the Femur. Together, the femoral head and the acetabulum constitute the bony framework of the hip joint.

The pelvic and sacral bones, joined by the sacroiliac joints and the Pubic Symphysis, form the pelvis, which is divided into the greater (false) and lesser (true) pelvis. The greater pelvis is bounded laterally by the iliac wings, and posteriorly by the lower lumbar vertebrae

and the Base of the sacrum. It is separated from the lesser pelvis by a line running anteriorly from the superior margin of the pubic symphysis to the base of the sacrum. The greater pelvis is open anteriorly, communicates inferiorly with the cavity of the lesser pelvis, and continues superiorly into the Abdominal cavity. It contains the Organs of the lower abdominal compartment (such as the small and large intestines). The lesser pelvis houses certain organs of the Urogenital System and the digestive tract (in females: the Uterus, Ovaries, rectum, Urinary Bladder, and Vagina; in males: the Prostate Gland, Seminal Vesicles, PARTS OF THE Ductus deferens, rectum, and urinary bladder), as well as Blood Vessels and nerves. The Muscles of the abdomen and thigh attach to the pelvic bones. The shape and dimensions of the pelvis exhibit Sexual Dimorphism; in females, the pelvis is wider and shallower than in males.

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Fig. 7. The pelvis

The Skeleton of the free lower limb is structurally similar to that of the upper limb and consists of the femur, the BONES OF THE leg, and the Bones of the FOOT. The femur is the largest and longest tubular bone in the human skeleton. Its proximal end features a head that articulates with the hip bone.

The neck of the femur connects the head to the shaft, forming an angle of approximately 130° with the latter. At the junction of the neck and shaft, There are two bony prominences called trochanters. The greater trochanter is located laterally on the outside and is easily palpable. The lesser trochanter is situated near the lower border of the neck, posterior to the greater trochanter. The distal end of the femur is expanded and presents two projections: the medial and lateral condyles.

The shaft of the femur is nearly cylindrical, curves anteriorly, and appears slightly twisted around its longitudinal axis.

The skeleton of the leg is formed by two bones: the thicker Tibia, located medially on the side of the big toe, and the Fibula, located laterally on the side of the little toe. Both belong to the category of long tubular bones. At the proximal end of the tibia, which participates in The formation of the knee joint, there are two articular condyles: medial and lateral. Two cartilaginous structures, the menisci, are interposed between the articular surfaces of the femoral and tibial condyles. Inferiorly, the tibia articulates with the talus of the tarsus (foot). The distal end of the tibia terminates in a downward-pointing process known as the medial malleolus, which is prominent and easily palpable. The fibula consists of a shaft and two extremities. The upper, proximal end features the head of the fibula. On its medial side, there is an articular facet for connection with the tibia. Inferiorly, the head narrows and transitions into the shaft via the neck of the fibula. The lower, distal end of the fibula is enlarged and forms the lateral malleolus, which extends further distally than the medial malleolus of the tibia.

The skeleton of the foot is formed by 26 bones, which include: the tarsus, consisting of 7 spongy bones (the talus, calcaneus, navicular, cuboid, and three cuneiforms); the metatarsus, consisting of 5 short tubular bones; and the bones of the toes (Phalanges).

The bones of the foot are connected by ligaments and Muscle tendons, forming the arches of the foot. The presence of these arches helps distribute loads evenly and provides elasticity and Shock absorption during walking.

Fig. 8. The femur

Fig. 9. Skeleton of the leg:

1 - tibial tuberosity;

2 - shaft of the bone; 3 - anterior border of the tibia;

4 - medial malleolus; 5 - lateral malleolus of the fibula;

6 - shaft of the fibula; 7 - head of the fibula;

8 - lateral condyle of the tibia.

Fig. 10. Skeleton of the foot:

1 - calcaneus;

2 - talus;

3 - navicular bone;

4 - cuboid bone;

5 - intermediate cuneiform bone;

6 - lateral cuneiform bone:

7 - medial cuneiform bone;

8 - Metatarsal Bones;

9 - proximal phalanges of the toes;

10 - middle phalanges; 11 - distal phalanges.