Question

Given diagram shows the bone of the left human hindlimb as seen from the front. It has certain mistakes in labelling. Which of the following pairs contains both wrongly labelled bones?

A. Tibia and tarsals
B. Femur and fibula
C. Fibula and phalanges
D. Tarsals and femur

Answer 1

Hint: Legs comprise the lower limbs of human beings. In most of the organisms, legs are composed of 30 bones. Just the foot comprises 26 bones.

Complete answer: There are 30 bones in each leg, namely the femur of the thigh region, the patella of the knee, the tibia and fibula of the lower leg, 7 tarsals of the foot, 5 metatarsals of the sole and 14 phalanges of the toes. The human foot phalangeal formula is 2,3,3,3,3. So, fibula and phalanges are numbered incorrectly.

The four lower limb bones are:
a) The femur is the largest lower limb bone in the body. It is generally referred to as the bone of the thigh. It is connected to the hip bone by a ball and a socket joint. The femur is a long, curved, robust bone. The compression forces of 800-1100 kg can withstand this.
b) The tibia is the second largest bone in the body and is vital for the body weight. The upper part of the tibia is connected to the joint of the knee, while the lower part is connected to the joint of the ankle. The tibia can be divided into the proximal, shaft and distal sections.
c) The fibula is the bone located in the lower leg. The tibia is parallel to it. It doesn't help with weight-bearing, but it does with muscle attachment. It also gives the joint ankle flexibility. It is divided into three sections: proximal, shaft and distal.
d) Tarsals along with metatarsals and phalanges, are a combination of seven bones found in the foot. Tarsals are located in the region of the foot ankle. Tarsal bones can be divided into proximal, intermediate and distal parts. Calcaneus is the largest tarsal bone present. The pair of fibula and phalanges is incorrectly labelled, based on the proper labelling shown.
So, the correct answer is option C.

Note: Femur, patella, tibia, fibula, tarsals, metatarsals and phalanges are present in the lower limb bones. The tarsals are composed of seven bones, the metatarsals are composed of five bones for each digit and the phalanges are composed of the bones of the toes. Tarsal and phalanges are connected to a metatarsal.