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The Skeletal System

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Basics on the topic The Skeletal System

The Human Skeleton and the Skeletal System

There are approximately 206 bones in the human body. These form an internal framework that gives us structure, which is necessary so that we don't collapse like a sack of flour. Together, the set of our bones is called the skeleton. Maybe you have already seen a human skeleton in your elementary school science class or labeled one on a worksheet?

How is the Human Skeleton Structured?

Our skeleton consists of different groups of bones. Each one can look different depending on the type of bone. For example, the thigh bone is shaped like a tube, while the hand bones fit together like puzzle pieces. The most important ones are shown in this picture:

SEO_25884_26139_Skeletton-01-01.svg

Bones are rigid, or hard. In order for us to still be able to move, we have something called joints. Joints connect two bones together. For example, if you want to bend your leg to sit on a chair, you use your knee joint to move and bend your leg. This joint only moves in one direction. Other joints, like the wrist joint, can move in different directions. You can see which joints are in your body here:

SEO_25884_26139_Joints-01-01.svg

The Spine - An Important Part of the Skeleton

The spine is a very special part of the skeleton. It is "double-S-shaped" and consists of 33 individual vertebrae, which are threaded together to form the spine. The spinal cord is found in the middle of the spine. The spine provides us with both support and mobility.

Overview: Functions of our Bones

Bones support our body in various ways. Here is an overview of the different functions of the human bones:

  • Stability: Without bones, the body would collapse.
  • Mobility: Since tendons and muscles are attached to the bones, we can move.
  • Protection against injuries: Bones are four times harder than concrete. For example, if you get hit in the head with a soccer ball, your brain is protected by 22 bones called the skull. Other bones, like your ribs, protect internal organs like the lungs and heart.
  • Calcium storage: The bones store calcium, which is important for blood, muscles, and nerves. If you don't get enough calcium through your diet, your body can draw it from the bones.
  • Production of red blood cells: Red blood cells are produced in the soft inner part of the bones called marrow.

How can our Skeleton Heal Itself?

One great ability of bones is the ability to repair themselves. The success and speed of this works differently depending upon age. This process is quick when you're young. If you break your leg while playing as a child, you go to the doctor and get a cast to immobilize your leg bone. Inside your bone, new bone tissue then forms, which gradually hardens. Your leg is completely stable again after only a few weeks. So you can run and play as usual. However, in older people, the bone takes longer to heal and may not be as stable as before. To keep your teeth and bones strong, it's important to get enough calcium. Dairy products, like cheese and yogurt, can help with that.

The Human Skeletal System – Summary

Let’s review what we learned about the human skeleton and the skeletal system. Below is an overview of some bones and joints in the human body.

examples
Bones skull, spine, ribs, forearm, thigh-bones
Joints spine, shoulder, elbow, hip, hand, knee, foot

Want to practice the human skeletal system some more? You’ll find interactive exercises, worksheets, and other activities next to the video.

Transcript The Skeletal System

Hello! There's no need to be scared. Haven't you ever seen a skeleton before? All vertebrates, or animals with a spine, have a skeleton, for example dinosaurs, dogs, snakes, and many more! In this video we will look at "The Human Skeletal System". Our skeleton consists of two-hundred six bones. Let's look at a few of our bones. This bone here, is an upper arm bone. Here is a finger bone, and this is a thigh bone. All our bones together form our skeleton. Where two bones meet is called a JOINT. A joint is a connection that holds together bones while providing support and allowing movement where it is needed. THIS is our spine. Our spine is made up of twenty-four moving vertebrae, or small bones. In between each vertebrae there are facet joints, which link them together and give them the flexibility to move against each other. Let's try it! Bend over and try turning your upper body. The skeleton is very useful. We actually need it to stand upright because the skeleton supports us on the inside, without bones our body would be quite wobbly! We call this the support function of the skeleton. In addition, our skeleton also protects us. Our skull protects our brain from getting injured.

Here, we have the rib cage. It is made up of twenty-four individual ribs that surround our heart and lungs to protect them!

Therefore, we can also say the skeleton has a protective function. Can you touch your ribs or skull? Go ahead, try it!

Our bones also store nutrients, like calcium! Inside a bone there is soft bone marrow. The bone marrow produces red and white blood cells along with other ingredients for our blood. So without bones, we have no blood! Bones can grow and make new bone cells! These cells can be used to heal a bone if you break it. But healing takes time! After a few weeks, the break is cured and the bone is as good as new.

Let's review what you have learned today. All our bones together form our skeleton. A joint is found where two bones meet, providing support and allowing movement where it is needed. The spine is made up of twenty-four moving vertebrae that support us and help us move at the same time. The entire skeleton has a support function, which helps us stand upright. The protective function means that bones, such as the skull or the ribcage, protect sensitive organs like the lungs and heart. Bones also serve as storage for important nutrients and produce components that we need for our blood. And if we break a bone, it can even heal itself! Our skeleton is just great!

13 comments
13 comments
  1. I like it so much.

    From Avash Acharya, about 2 months ago
  2. so cool

    From Averie, 12 months ago
  3. so meny bones

    From Averie, 12 months ago
  4. Our body are cool

    From Aleena, 12 months ago
  5. 206 bones omg

    From Aleena, 12 months ago
More comments

The Skeletal System exercise

Would you like to apply the knowledge you’ve learned? You can review and practice it with the tasks for the video The Skeletal System.
  • Label the bones of the skeleton.

    Hints

    The skull is the part of the skeleton that protects the brain.

    The rib cage is the part of the skeleton that protects the organs such as the heart and lungs.

    The spine runs down the back and is made up of 33 vertebrae (small bones).

    The femur is in the upper part of the leg.

    The hip bone is right at the top of the leg.

    Solution

    Here are the correctly labelled parts of the skeleton.

    There are many more parts to the adult skeleton, since it has 206 bones in total.

  • Vertebrates and invertebrates

    Hints

    Animals that have a backbone include: mammals, reptiles, amphibians, birds, and fish.

    Animals that do not have a backbone include insects, crustaceans, and mollusks.

    Solution
    • Vertebrates (animals with a backbone) include: mammals, reptiles, amphibians, birds, and fish.
    • The vertebrates here are: cat (mammal), frog (amphibian), a bird, and a fish.
    • Invertebrates (animals without a backbone) include: insects, crustaceans, and mollusks.
    • The invertebrates here are: butterfly (insect), spider (arachnid), octopus (mollusk), and a crab (crustacean).
  • Protective skeleton.

    Hints

    This part of the skeleton wraps around our bodies to protect our internal organs such as the heart and lungs.

    The skull of this platypus can be seen here in pink.

    Solution

    The correct answer is the skull and the rib cage.

    The skull protects the brain.

    The rib cage protects the internal organs such as the heart and the lungs.

  • Highlight the joints on the skeleton.

    Hints

    The joints to find in this task are in pairs, there is one on each side of the body in the same area.

    The joints allow us to bend parts of our body, think about which parts of your body easily bend back and forth or left and right.

    The joints are found where two bones meet.

    Solution

    There are acutally over 300 joints in the human body. Here are some of the main joints labelled on the skeleton.

  • Animal skeletons.

    Hints

    Look at the outline of the body. Can you see a similar outline in the skeleton?

    This image shows the skeleton of a fish.

    Solution

    Here are the 4 images matched:

    • a dog
    • a child
    • a snake
    • a crocodile

  • The human skeleton.

    Hints

    This is the spine, it is naturally curved and is made up of lots of smaller bones called vertebrae.

    The human skeleton has lots of functions, two of these are to support and protect the body.

    The adult human skeleton is made up of 206 bones and 360 joints.

    Solution

    The adult, human skeleton is made up of 206 bones in total. Our skeletons have many functions including support - keeping our bodies upright and protection - keeping our organs safe.

    The part of our skeleton that runs down our backs and keeps us upright is called the spine. The adult spine is made up of 24 smaller bones known as vertebrae.

    Many species in the animal world have a backbone, such as lions and lizards, these are known as vertebrates. Those without a backbone, such as jellyfish, are known as invertebrates.

    It is important that we look after our bones by eating healthy foods containing calcium. However, if we break a bone, it can usually heal itself.

    Without our bones, parts of our bodies would be unprotected, for example, the brain is protected by the skull and the heart and lungs are protected by the rib cage. Aren't our skeletons amazing!