Classification of skeleton: Appendicular-2

The Pelvis

The lowest part of the body is called the pelvis. The pelvic brims are a border that separates the bony pelvis' superior and inferior halves. False (larger) pelvis refers to the portion of the bony pelvis above (superior) to the pelvic brim, and true (lesser) pelvis refers to the portion below the pelvic brim. It is made up of two hip bones that connect to the sacrum posteriorly at the sacro-iliac joints and the anteriorly at the symphysis pubis. Strong ligaments surround the bones. Large surfaces for attaching muscles of the lower extremities are provided by the pelvic girdle. The pelvis in women has evolved to accommodate pregnancy and childbirth.

Bones of the Lower Limbs

There are 30 bones in four places in each lower limb.

• The thigh's femur.
• The leg's tibia and fibula.
• The patella (knee cap).
• The phalanges, metatarsals, and tarsal.

Femur

The largest, heaviest, and sturdiest bone in the human body is the femur, or thigh bone. It has a lot of muscle on it. It transfers the entire trunk's weight from the hip to the tibia. The femur has two trochanters, a head, and a neck at its upper end. The head of the hip bone fits into the acetabulum almost perfectly to form the hip joint. Distal to the head, the femur's neck is a constrictive area. The tendons of the buttock and thigh muscles attach to the greater and lesser trochanters, which are protrusions from the neck and shaft junction. The medial and lateral condyles are two substantial masses at the distal end of the femur. Large articular areas on the underside of the distal end meet the head of the tibia to form the sturdy knee joint. The patella also articulates with the femur. On the anteiror surface, the patellar surface is situated between the candyles.

Patella

An anterior sesamoid bone with a tiny triangular shape houses the patella, or knee cap. It develops in the knee tendon as a youngster learns to walk. The patella, the largest sesamoid bone in the human body, is a part of the quadriceps tendon. The quadriceps, the anterior thigh muscle, and the patella are connected by the patellar tendon, which continues as the patellar ligament from the patella to the tibia.

Tibia

The two bones that make up the leg are the lateral, thin fibula and the thick, robust tibia. The bigger medial weight-bearing bone of the leg is called the tibia, or shin bone. It transmits foot weight and is second in length to the femur. The medial and lateral condyles, which are separated by a ridge known as the intercondylar eminence, have two flat articular surfaces on the head's proximal end. The femur's condyles and the tibial condyles articulate. The articular area for the talus is located on the underside of the lower end of the tibia, which also widens (one of the tarsal bone). The medial malleolus, a projection of the tibia, creates the prominence of the ankle on the medial side. Both above and below, the tibia articulates, with fibula of all the long bones of the body, the tibia is the most frequently fractured and is also the most frequent site of an open (compound) fracture.

Fibula

The tibia and fibula are side-by-side and parallel. Although it is connected to the tibia on both sides, it does not contribute to the development of the knee joint. The distal end of the fibula articulates with the talus of the ankle, and the head of the fibula articulates with the inferior surface of the lateral condyles of the tibia below the lend of the knee joint. Although it does not support the weight of the body, this creates the prominence on the lateral surface of the ankle and aids in stabilizing it.

Tarsals, Metatarsals and Phalanges

The tarsus (ankle), which is located closest to the foot, is made up of seven tarsal bones. They are situated in the back of the foot and consist of the talus (ankle bone) and calcaneous (heel). The largest and sturdiest tarsal bone is the calcaneous. The talus, which articulates with the underside of the leg bone, is the second-largest tarsal bone (tibia and tibula). The following bone in the proximal group is the navigable. The first, second, and third cuneiforms, along with the cuboid, make up the distal group's row of four bones. The arrangement of the bones of the foot and hand is comparable. From medial to lateral, they are metatarsals I to V. Phalanges are the names given to the toes' bones, just like they are to fingers. A number of 14 phalanges in each foot. Of these, 2 are in the great toe (hallux) and 3 in each of the toes.

Arches of the Foot

For the same reason that the spine is curved, the sole of the foot is arched. In addition to serving as a shock absorber, it guards against crushing the nerves and blood vessels in the foot's sole. The foot has three arches: one transverse and two longitudinal (medial and lateral) arches.

• Medial longitudinal arch
• Transverse arch
• Lateral longitudinal arch