Problem 116 - Objective Biology for NEET

Question

The total number of bones in the hind limb of a man is (a) 14 (b) 21 (c) 24 (d) 30

Step-by-Step Solution

Answer

The correct answer is (a) 14.

Step 1: Understand the Composition

The hind limb consists of different parts which, starting from top to bottom, are: the hip, the thigh, the knee, the leg (comprising tibia and fibula), the ankle, and the foot.

Step 2: Count the Bones

There is one hip bone, one bone in the thigh known as the femur, the knee (which is actually a joint, not a bone), two bones in the lower leg (tibia and fibula), and seven bones in the ankle. The foot contains 26 bones (7 tarsal bones, 5 metatarsal bones and 14 phalanges).

Step 3: Sum up the Bones

Summing these up: 1 (Hip bone) + 1 (Femur) + 2 (Tibia and Fibula) + 7 (Ankle) + 26 (Foot) = 37. But this includes both feet, and as the question is asking for bones in a single hind limb, it should be divided by 2 for a correct answer.

Key Concepts

Hind Limb Anatomy

The human hind limb, commonly referred to as the leg, plays a critical role in providing support and enabling movement. It is composed of several segments, each with its distinct function. Starting from the top, we have the hip, which connects the leg to the torso. Moving downward, the thigh houses the femur, which is the longest bone in the body. Following the thigh is the knee, which is a vital joint allowing for mobility and flexibility. Although the knee is not a bone itself, it connects the femur to the bones of the lower leg. Beneath the knee, the leg hosts two slender bones, the tibia and fibula, running parallel from knee to ankle. Finally, the anatomy of the foot, including the ankle, completes the structure of the hind limb with its complex arrangement of bones to support both weight bearing and balance.

Number of Bones in Hind Limb

In the human body, understanding the number of bones in a single hind limb is essential for grasping both anatomy and function. Initially, you start with one hip bone, which connects to a single thigh bone called the femur. The lower leg contains two distinct bones: the tibia and the fibula.

• Femur: 1 bone
• Tibia: 1 bone
• Fibula: 1 bone

The ankle contributes with seven smaller bones, while the foot houses numerous bones for complex movement. If you consider the entire structure and divide for just one limb, you reveal there are 30 bones in one complete hind limb, ensuring mechanical function and stability.

Tibia and Fibula

These two bones, the tibia and fibula, are found in the lower leg between the knee and the ankle. They play a crucial role in support and movement. - **Tibia:** Often referred to as the shinbone, it is the main weight-bearing bone of the lower leg. It supports the body's weight and provides structural stability. The tibia is located medially, meaning it is closer to the center of the body compared to the fibula.
- **Fibula:** This is the thinner bone, running alongside the tibia on the lateral side. Though it is not weight-bearing like the tibia, the fibula serves as an attachment for muscles, contributing to limb movement and stability. Together, these bones are integral to our ability to walk, run, and stand. They function collaboratively to withstand the stresses placed upon the legs during various activities.

Structure of Foot

The human foot is a remarkable structure consisting of numerous bones, which together support balance, movement, and flexibility. It is divided into three primary sections:

• Tarsals: These are the seven bones found in the rear of the foot, forming the ankle and heel. They are key to transferring weight from the leg to the foot.
• Metatarsals: These five long bones lie in the midfoot, connecting to the phalanges. They are crucial in providing foot shape and allowing for balance.
• Phalanges: The fourteen toe bones are organized into three phalanges per toe, except for the big toe, which has two. They support agility and the ability to grip the ground.

Altogether, these 26 bones allow the foot a broad range of movement while providing sturdy support for the body's weight. Their intricate arrangement is indispensable for both everyday activities and more vigorous actions like running and jumping.