Human Anatomy: Lecture Notes - Savchuk O.I. 2017

Skeleton of the lower limb

Lecture Outline

1. Anatomy of the Pelvic Girdle bones

2. Articulations of the pelvic girdle bones

3. The Pelvis as a whole

4. Structure OF THE Femur

5. BONES OF THE lower leg

6. Anatomy of the FOOT bones

The Skeleton of the Lower Limb consists of the pelvic girdle and the free lower limb. The girdle includes the paired, massive hip bone. The free limb is divided into the thigh (represented by the femur), the leg (Tibia and Fibula), and the foot: tarsus, metatarsus, and Phalanges.

Bones of the pelvic girdle and their articulations.

Until the age of 16, the hip bone consists of three separate bones: the ilium, pubis, and ischium. After age 16, their bodies fuse together to form the acetabulum, which receives the HEAD of the femur.

The ilium consists of a body and a wing (ala). The wing is expanded and directed upward, ending in the iliac crest. Anteriorly, the crest features the anterior superior and anterior inferior iliac spines, and posteriorly, the posterior superior and posterior inferior iliac spines. On the pelvic surface of the wing, There is a depression called the iliac fossa. Posterior to it lies the auricular articular surface for articulation with the corresponding surface of the sacrum.

On the outer surface of the wing, there are gluteal lines that serve as attachment sites for the gluteal Muscles. The wing is demarcated from the body by the arcuate line.

The ischium consists of a body and a ramus, which thickens to form the ischial tuberosity. Above the tuberosity is the ischial spine, and superior to the spine is the greater sciatic notch.

The pubic bone consists of a body, as well as superior and inferior rami. At the junction where the rami meet, the symphysial surface of the Pubic Symphysis is formed. The rami of the ischium and pubis enclose the obturator foramen. Posteriorly, the bones of the pelvic girdle articulate with the sacrum via the paired, slightly mobile sacroiliac joint, which is a plane joint. It is formed by the auricular surfaces of the sacrum and ilium. Anteriorly, they form an unpaired amphiarthrosis (half-joint) — the pubic symphysis. Here, the pubic bones are joined by Cartilage containing a small fluid-filled cleft. The intrinsic ligaments of the pelvis include the sacrotuberous and sacrospinous ligaments. They close off the sciatic notches, converting them into the greater and lesser sciatic foramina, through which muscles, vessels, and nerves pass.

The pelvis as a whole.

The pelvis is formed by the hip bones, sacrum, coccyx, and their articulations. It is divided into the greater (false) and lesser (true) pelvis. The boundary between them is the pelvic brim (linea terminalis), which runs from the promontory along the arcuate lines of the ilia, then along the superior rami of the pubic bones to the superior border of the pubic symphysis.

The greater pelvis is formed by the wings of the iliac bones and Supports the Internal Organs of the Abdominal cavity.

The lesser pelvis is formed by the pelvic surfaces of the sacrum and coccyx, as well as the ischial and pubic bones. It features the superior and inferior pelvic apertures (pelvic inlet and outlet) and the pelvic cavity. The lesser pelvis contains the Urinary Bladder, rectum, and internal reproductive organs (the Uterus, uterine tubes, and Ovaries in females; the Prostate Gland, Seminal Vesicles, and Ductus Deferentes in males). The female pelvis is wider and shorter than the male pelvis, its alae are broader, and the subpubic angle is obtuse (whereas in males, it is acute). The female sacrum is also shorter, wider, and flatter.

Dimensions of the female pelvis.

Greater pelvis:

1) interspinous distance - the distance between the anterior superior iliac spines (26 cm);

2) intercristal distance - the distance between the most lateral points of the iliac crests (29 cm);

3) intertrochanteric distance - the distance between the greater trochanters of the femurs (30 cm).

Lesser pelvis.

1) external conjugate - the distance between the pubic symphysis and the promontory (20-21 cm);

2) diagonal conjugate - the distance between the inferior border of the pubic symphysis and the sacral promontory (12.5-13 cm);

3) gynecological conjugate - the distance between the most prominent part of the pubic symphysis and the sacral promontory (10.5-11 cm);

4) anteroposterior diameter of the pelvic outlet - the distance between the inferior border of the symphysis and the tip of the coccyx (10 cm). During labor, it increases by 1.5 cm as the coccyx deflects.

5) pelvic inclination - the angle formed by the horizontal plane and the pelvic inlet.

Bones of the free lower limb

The femur is the longest bone in the human skeleton. At its proximal end is the head, followed by the neck, with the greater and lesser trochanters located superiorly and inferiorly to it. The posterior surface of the shaft features the linea aspera, which consists of medial and lateral Lips.

Anterior view: fovea of the head, from which the ligament of the head of femur arises. Intertrochanteric line; posteriorly: trochanteric fossa, intertrochanteric crest, and gluteal tuberosity. The distal end is thickened due to the presence of the medial and lateral condyles, which bear the corresponding epicondyles. Anteriorly between the condyles is the patellar surface, and posteriorly is the intercondylar fossa and the popliteal surface.

The Patella (kneecap) is a rounded bone, the posterior surface of which features an articular surface for articulation with the femur. It has a Base of the patella and an apex of the patella.

Tibia: It lies medially in the leg. The proximal end bears the lateral and medial condyles, which have articular surfaces for articulation with the femur. The shaft has a trihedral shape with a sharp anterior border.

Anteriorly: intercondylar eminence, medial and lateral condyles; tibial tuberosity; Medial surface of the tibia; lateral surface; anterior border of the tibia; interosseous border of the tibia; medial border, medial malleolus.

The distal end contains the inferior articular surface (for articulation with the talus) and the medial malleolus.

Posteriorly: lateral and medial intercondylar tubercles, malleolar groove on the medial malleolus; posterior surface; soleal line.

Fibula: It lies laterally in the leg. The proximal end bears the head with an articular surface (for articulation with the tibia), the apex of the head; interosseous border of the tibia; anterior border of the fibula; medial surface, lateral surface.

The distal end features the lateral malleolus, which bears an articular surface for articulation with the talus. Posteriorly: posterior surface, lateral surface.

Tarsal Bones

The tarsus consists of the following bones: the talus, calcaneus, cuboid, navicular, and three cuneiform bones (medial, intermediate, and lateral).

The talus has a head with an articular surface (directed anteriorly), followed by the neck, and then the body. On top of the body is the trochlea for articulation with the tibia, and on the inferior surface are articular surfaces for articulation with the calcaneus. The lateral process is located on the body.

Calcaneus

It lies beneath the talus and consists of a body and a rough tuberosity (calcaneal tubercle) directed posteriorly and inferiorly. The body bears articular surfaces for articulation with the talus and cuboid bones.

Metatarsal Bones.

The metatarsus consists of five short bones, each of which has a head, a shaft (body), and a base.

Phalanges of the toes

Each toe, except the great toe, has three phalanges: proximal, middle, and distal. The great toe has only proximal and distal phalanges. The connections between the bones of the free lower limb include both continuous (syndesmoses) and discontinuous joints (synovial joints). The hip, knee, and ankle (talocrural) joints are of the greatest clinical importance.

Hip joint

It is formed by the articular surface of the head of the femur and the acetabulum of the hip bone. Structurally, it is a simple joint; morphologically, it is a cotyloid (cup-shaped) joint; and functionally, it is a multiaxial joint. It is a variety of ball-and-socket joint, allowing movements around all axes, though to a somewhat limited extent. Inside the joint, there is an acetabular labrum (to better encompass the articular surface of the head) and the ligament of the head of the femur (ligamentum teres), which carries the Vessels and nerves supplying the head. The strongest ligament reinforcing the joint (capable of withstanding a load of up to 300 kg) is the iliofemoral ligament, along with the ischiofemoral ligament and the zona orbicularis.

Knee joint

It is formed by the articulation of three bones: the condyles of the femur and tibia, and the patella. This is a highly complex joint, containing the medial meniscus, and the anterior and posterior cruciate ligaments. The Joint Capsule forms numerous recesses (bursae). Structurally, the joint is compound; anatomically, it is a condylar joint; and functionally, it is biaxial. It allows flexion and extension, and, when the knee is flexed, rotation around the vertical axis (due to the relaxation of the collateral ligaments that reinforce the capsule).

Articulations between the bones of the lower leg.

The proximal ends of the tibia and fibula form a plane, slightly movable joint. The shafts of these bones are connected by a syndesmosis (interosseous membrane), and their distal ends are also joined by a syndesmosis (ligaments).

Ankle joint (talocrural joint)

It is formed by the distal ends of the tibia and fibula, whose articular surfaces clasp the talus like a mortise. Structurally, this joint is compound; anatomically, it is a hinge joint; and functionally, it is uniaxial.

It allows flexion and extension of the foot around the frontal axis.

Tarsal bones

They articulate via joints whose capsules are reinforced by short ligaments on both the plantar and dorsal surfaces of the foot. Among the movements in these tarsal joints, the talonavicular and calcaneocuboid articulations are of practical importance; surgeons combine them into a single transverse tarsal joint known as Chopart's joint. Disarticulation of the foot can be performed along the line of this joint by cutting the bifurcate ligament, which runs from the calcaneus on one side to the navicular and cuboid bones on the other. This ligament is called the "key" of Chopart's joint and divides into two parts. The tarsal bones articulate with the bases of the metatarsal bones, forming the slightly movable tarsometatarsal joints. In surgery, these are known as Lisfranc's joint. Its "key" is the medial tarsometatarsal interosseous ligament.

The metatarsophalangeal and interphalangeal joints are similar in structure and movement to the corresponding JOINTS OF THE hand.

The foot (pes) serves as a support during standing and walking. The bones form the arches of the foot. There are five longitudinal arches (corresponding to the five rays of the foot) and one transverse arch. All longitudinal arches begin at the calcaneus and extend forward along the metatarsal bones. In the transverse direction, all five arches vary in height, forming a transverse arch at their highest point. These arches are reinforced by ligaments, muscles, and fasciae. When this supporting apparatus weakens, the arches flatten, leading to The Development of Flatfoot.

References:

1. Haida S.P. Human Anatomy and Physiology. Kyiv: Vyshcha Shkola, 1980.

2. Dybenko K.A. Anatomical Ukrainian-Latin-English Dictionary and Reference Book. Kyiv: Dovira, 1997. - 344 p.

3. Kravchuk S. Yu. Human Anatomy. Chernivtsi: Podillia, 1998. - Vol. 1. - 291 p.

4. Kravchuk S. Yu. Human Anatomy. Chernivtsi: Podillia, 1998. - Vol. 2. - 339 p.

5. Mateshchuk-Vatseba L. R. Normal Anatomy: Textbook. Lviv: Poklyk Sumlinnia, 1997. - 267 p.

6. Ivanitsky M. F. Human Anatomy. Moscow: Fizkultura i Sport, 1985. - 480 p.

7. Sapin M. R., Bilich G. L. Guide to Practical Classes in Human Anatomy. Moscow: Vysshaya Shkola, 1989. - 543 p.

8. Sinelnikov R. D. Atlas of Human Anatomy (Multi-volume edition "Meditsina". By body systems).

9. Great Medical Encyclopedia. Sections: Human Anatomy, by body systems.

10. Anatomy and Physiology with Pathology // Ed. by Fedoniuk Ya. I., Bilyk L. S., Mykula N. Kh. Ternopil: Ukrmedknyha, 2001.