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Exploring how our bones provide a frame and protection for our bodies.
What if your body was like a giant pile of jelly? Without your bones, you wouldn't be able to stand up, walk, or even sit in your chair!
Just like a house needs a wooden frame to stay standing, your body needs the skeletal system. This system is made up of all the bones in your body. An adult human has exactly bones! These bones provide support, giving your body its shape. Without them, you would be a floppy heap on the floor. Bones also allow for movement by acting as levers that your muscles pull on. Finally, bones are actually 'blood factories'—inside many bones is a gooey center called marrow that creates new blood cells for your body.
Quick Check
What are the three main jobs of the skeletal system mentioned above?
Answer
Support (shape), movement, and making blood cells.
While you have hundreds of bones, a few are very famous! The Skull is the hard bone that makes up your head. The Ribs are curved bones in your chest that act like a protective cage. Down in your leg, you have the Femur. The femur is your thigh bone, and it is the longest and strongest bone in your entire body. If you are feet tall, your femur is roughly of your total height, or about feet long!
Let's look at why the femur is so important: 1. It supports the entire weight of your upper body when you stand. 2. It connects your hip to your knee. 3. Because it is so thick, it is very hard to break, which is good because you use it for every step you take!
Quick Check
Which bone is the longest and strongest in the human body?
Answer
The femur (thigh bone).
One of the most important jobs of your bones is protection. Think of your bones as 'natural helmets.' Your Skull is a thick, rounded bone designed specifically to shield your brain, which is very soft and delicate. Similarly, your Rib Cage wraps around your chest to protect your heart and lungs. If you accidentally bump your chest or head, these hard bones take the hit so your vital organs don't get hurt. It's like wearing a suit of armor hours a day!
Imagine you are playing soccer and a ball hits you in the chest. 1. The impact hits the hard Ribs first. 2. The ribs are slightly flexible, so they absorb the energy of the hit. 3. The heart and lungs inside stay safe and untouched because the 'cage' blocked the ball.
Babies are actually born with about bones, but adults only have . 1. As you grow, some of your smaller bones fuse (join) together to make bigger, stronger bones. 2. If a baby has bones and an adult has , how many bones 'disappeared' by joining together? 3. Calculation: bones.
What is the main purpose of the Rib Cage?
How many bones does an average adult human have?
The femur is the bone found in your arm.
Review Tomorrow
In 24 hours, try to remember the names of the bones that protect your brain and your heart without looking at this guide.
Practice Activity
Feel your own body! Gently touch your knee, your ribs, and your elbow. Notice how hard the bone feels compared to your skin and muscles.