Longest Bone In The Body: Fascinating Human Body Facts For Kids!

Read these amazing acts about the longest bone in the body.

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There are 206 bones in the human body!

The bones in the human body are classified into five groups: flat bones, short bones, long bones, sesamoid bones, and irregular bones.

The longer and wider bones in the human body come under the long bone category. The femur, tibia, fibula (legs), humeri, ulna, radius (arms), and the metacarpals and metatarsals (hands and feet) are long bones. The long bones in our legs contribute to half the height of an adult human body. Long bones have an outer layer that is made of cortical or compact bone. The outer layer is further covered by a connective tissue known as the periosteum. Beneath the cortical bone, there is a spongy cancellous bone. The femur is the longest bone in the human body.

Continue reading to know more about the longest bone in the human body. Once you have finished reading this article, you can also read all about the bones in the human body and cool anatomy fun facts.

What is the longest bone in the body?

The femur, or the thigh bone, is the largest bone in the human body. Apart from this, it is also one of the most researched bones in human anatomy.

The length of the femur in an adult is 18.9 in (48 cm) in length and 0.92 in (2.34 cm) in diameter. The femur forms a connection with the hip joint and is a major part of the knee joint. The femur has the following four structures: the head, the greater trochanter, the smaller trochanter, and the lower extremity. The head and shaft are connected by the collum. All these four structures are the main components of the femur and emerge at different periods. At first, these four structures are connected to the femur's main body by cartilage. This cartilage ossifies as time passes. The ossification continues until the structures become an integral component of the femur bone by the time a child becomes an adult. The primary function of the femur is to carry the body's weight and provide stability while a person is walking or doing any other physical activity. It also connects the tibia and fibula, which form a major part of the lower leg to the upper body.

The smallest bone in the human body is a stape. Stapes are present in the middle ear regions.

What are the three largest bones?

The three longest bones in the human body are the femur, tibia, and fibula. These bones are commonly known as the thigh bone, shinbone, and lower leg bone, respectively.

The femur is divided into three parts: the upper extremity, the main body or shaft, and the lower extremity. The upper extremity is the shortest, while the lower extremity is the thickest. The body has a cylindrical form and is thick and large. Since it is a long bone in the human body, it has two marrows, yellow marrow and red marrow.

The tibia is the second longest bone in the human body. In females, the tibia is slightly shorter. There is also a minute difference in the length of the right tibia and left tibia. Typically, in males, the length of the right tibia is 14.3 in (36.45 cm), and the left tibia is 14.4 in (36.48 cm). The right tibia of a female is typically 13.5 in (34.5 cm), and the left tibia is 13.6 in (34.6 cm). They are attached to the foot bones. The tibia is the larger bone located in the lower leg. The tibia is a weight-bearing bone thats chief function is to distribute weight to the ankle and knee.

Typically, in males, the length of the fibula is 15.9 in (390 mm), while in females, it is (14 in) 360 mm long. The fibula is present along with the tibia. It is the smaller bone that is placed outwards. It works along with the tibia and provides firmness to the ankle joint. The word fibula is derived from a Latin word that means clasp or brooch.

Apart from these three bones, the humerus (upper arm), radius (forearm), ulna (lower arm), metatarsals (middle foot), and phalanges are some of the other long bones in the skeleton. The humerus runs parallel to the ulna and is positioned on the lateral side of the forearm. The ulna nerves are prone to being knocked since they run around the humerus. This gives you a tingling sensation in your arm.

Femoral shaft fractures are said to be the most painful fracture.

Which bone is the longest and hardest?

The femur is the longest and strongest bone located in the lower leg.

The femur is located in the thigh. It is an inward-facing bone that runs from the pelvis to the knee. The joint which connects the pelvis and femur is called the hip joint. Patella, a bone present between the thigh and lower leg, protects the knee and improves the leg's capacity to operate. There is a protrusion in the lower extremity of the femur called the medial femoral condyle. The medial femoral condyle bears most of the weight. There are several muscles that protect this bone and offer additional support. The femur is as strong as concrete. It can sustain heavy damages and only breaks due to vehicle collisions or other similar events. A break in the femur is called a femoral shaft fracture. Femoral shaft fractures are said to be the most painful fracture. Some of the common fractures in this bone are as follows.

When there is a horizontal line that runs straight across the shaft, it is called a transverse fracture.

Spiral fractures are caused by the application of a twisting force. The fracture lines spiral the body of the femur.

In an oblique fracture, there is an angled line across the body of the femur.

An open or complex fracture occurs when a bone fractures in a way where the bone pieces protrude through the skin. This fracture is accompanied by damage in the muscles, ligaments, and tendons around the area. People who have this type of fracture are prone to infections and other complications. Healing takes a while.

When the bone has broken into many pieces, it is called a comminuted fracture. The amount of force applied to the bone corresponds to the number of bone fragments.

The weakest bone in the human body is the clavicle, which is also known as the collarbone. A clavicle fracture is the most common fracture.

What is the longest and heaviest bone in the body?

The femur is the longest and heaviest bone in the human body. This long bone is strong enough to support up to 30 times the weight of an adult.

The femur can handle 6,000 lbs (2721.5 kg) of compressive force. The weight of the femur in males is 0.6 lbs (290 gms), and, in females, it is o.5 lbs (260 gms). All other leg bones are linked to the distal end of the femur, which is the major bone of the leg. Red bone marrow, which is involved in the generation of red blood cells, is found in the medullary cavity. Red bone marrow is gradually replaced by yellow bone marrow. Yellow marrow aids in fat storage. Blood flow in the femur is difficult to quantify. 

Did you know the foot bones, calenus and talus, are the two bones that carry most of the weight of the body?

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for 'Longest bone in the body: fascinating human body facts for kids!' then why not take a look at 'Goat vs lamb meat: which is healthier? Here's all you need to know', or 'Oldest river in the world: amazing facts on world's rivers for kids pages?'


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Kidadl Team

The Kidadl Team is made up of people from different walks of life, from different families and backgrounds, each with unique experiences and nuggets of wisdom to share with you. From lino cutting to surfing to children’s mental health, their hobbies and interests range far and wide. They are passionate about turning your everyday moments into memories and bringing you inspiring ideas to have fun with your family.

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