Skeleton - Understanding your skeleton.doc
Post on 09-Oct-2015
Did you really mean that
Understanding your skeleton: WORKSHEET
A skeleton, the framework of bones which support the body. The bones in the skeleton are connected by joints so that we can bend our arms and legs. Muscles are joined to bones so that we can control our movements. Some muscles, like the muscles in our legs, are big and strong. Other muscles, like the muscles in our faces are smaller and less powerful.
Humans first developed in East Africa when apes who had lived in trees moved down to ground level and started to walk upright on two legs. Anatomists, who study human bodies, have compared the human skeleton with the skeletons of apes. They have seen many differences, and in the article below comments on those differences.
The main bone of the head is called the skull. If we compare a human skull and an ape skull, we can see that humans have much bigger brains. When human babies are born their brains are big but underdeveloped. Babies spend many years learning how to use their brains.
The second big bone in the head is the jaw, the big bone under the mouth. We use the jaw to open and close our mouths and to eat. Apes have much bigger jaws because they dont use knives and forks. They bite their food and pull leaves away from the plant or meat from the bones of the animals they kill. Our teeth are much smaller than the teeth of chimpanzees and gorillas. This is because the food we eat is softer and easier to chew.The head is attached to the neck at top of the spine (back bone) with a very strong ligament which helps us to hold our heads upright when we are standing, walking or running. Apes dont have this strong ligament because they usually use four feet when they run.
In chimpanzees, gorillas and humans, the arm is divided into two parts, the upper arm with one big bone and the lower arm or forearm containing two bones. The upper arm and lower arm are joined by a joint called the elbow. This combination of bones mean we can move our hands through 180 degrees. Look at the back of your hand. Now turn your hand to look at the palm. Notice the way in which the bones of your forearms are moving when you do this.
The hand is the most complicated part of our bodies. We use our hands to grip and pick up a heavy rock or a single pin. We use our hands to fight and to play the piano. We have many bones in our ten fingers but no muscles. Our fingers are moved by long sinews attached to muscles in the forearm.
If we look at the hand of a chimpanzee or gorilla, it seems to be the same as a human hand, but in fact our thumbs are bigger. When humans started to use tools, they needed stronger and more precise hands for making delicate movements.
If we look at the central part of the upper body, we can see our rib cage. The rib cage is made from small bones, called ribs. The ribs are joined together by a central bone called the sternum. The rib cage protects the heart, the lungs and other organs.
Below the rib cage we can see the bones of the pelvis. If you look at the pelvis of a cat or dog, its quite small. The human pelvis is bigger because we walk on two legs. Women have a bigger pelvis than men because they need to carry and give birth to a baby.
The pelvis is also important for humans because it twists when we are walking. Apes who lived in trees did not need a pelvis which twisted in this way.
When we start to look at the legs, we can see the biggest difference between apes and humans. Human legs are much longer. The bones in the legs are similar to the bones in the arm; one strong bone in the upper leg, called the femur and two lighter bones in the lower leg. The joint between the upper leg and lower leg is called the knee.
Humans have long legs because they are good for walking and running. Humans can run for long distances, but apes cant. Apes have shorter legs.
In humans, the knee joint can lock, holding the person in an upright standing position. Look at gorillas standing. Their knees are not locked in the same way.
If we compare the feet of humans with the feet of apes we can see the biggest difference. An ape can use its feet to hold on to the branch of a tree. We cant do that. There are the same number of bones in an ape foot and a human foot but a human foot does not have the same abilities as an ape foot.
1Vocabulary: Touch your
Work in pairs. Student A uses the vocabulary in the box to give instructions to Student B. Student B listens and follows the instructions.lower legkneefootforearmneck
2Comprehension: Complete the sentences
Complete the sentences. Choose a), b) or c).1) The framework of bones in our bodies is called
a) a skeleton.
b) a rib cage.
c) a pelvis.
2) Human jaws are
a) bigger than ape jaws.
b) smaller than ape jaws.
c) the same size as ape jaws.
3) Our brains are inside our
a) rib cage.
4) Humans have . teeth than apes.
5) The between the upper arm and forearm is called the elbow.
6) We havent got any in our fingers.
7) Our rib cage protects our
a) heart and lungs.
c) scull and pelvis.
8) We can lock our knees so we can
a) have babies.
b) stand upright.
c) climb trees.
9) When we walk, we twist our
10) Humans and apes have in their feet.
a) more muscles
b) the same number of bones
Use the information in the article and any other knowledge you have to discuss the questions below.1) How did the change in diet change the human skeleton?
2) How did the change from four feet to two feet change the human skeleton?
3) How did using tools change the human skeleton?
How many of the word Exercise A do you know in your own language? If you dont know the words, use a textbook, dictionary or diagram to learn the words.
Look at skeleton of a bird or a fish. Describe the bones you can see.Key
B1a, 2b, 3c, 4b, 5c, 6c, 7a, 8b, 9a, 10b
DOpen answers (students may need to be directed towards sources for this information)
EOpen answersLesson submitted by Suzie Davis
Lesson submitted by Suzie Davis