The muscular-skeletal system in vertebrates
As previously discussed, a multicellular organism is one composed of
many cells. The organism has a number of body systems, each of
which play a vital role in keeping the organism alive. For example, the
digestive system works to ensure that each cell in the organism has a
supply of nutrients.
In the following activities, you will learn about the role of the body
system called the muscular-skeletal system. You will learn more
about different body systems in later topics.
Introducing the muscular skeletal system
Activity #1-Brainpop- "Bones"
You will watch the Brainpop on Bones. Record the main ideas from the
Brainpop below:
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Activity #2
The major parts of the system
The main structures of the muscular-skeletal system are shown in the
table. Use the Internet of a science text to complete the table.
Structure
Bones
Muscles
Tendons
Ligaments
Joints
Definition
The role of the system
A major role of the muscular-skeletal system in multicellular animals is to
allow the animal to move around in it’s environment. This ability to move
is essential to animals because animals, unlike plants, need to find their
own food. Plants have the ability to produce their own food, by a process
known as photosynthesis, and therefore do not need to move in their
environment. Being able to move also allows animals to run from
predators and to find mates to reproduce.
Movement is not the only role of this system. The bones in an animal
support the animal’s body against the force of gravity. Put simply, the
skeletal system holds the body upright. Bones also protect the delicate
organs which lie inside the body.
Finally, bones contain bone marrow which produces many of the blood
cells the body needs.
Activity # 3
Questions:
1. Outline THREE functions of the skeletal system in animals.
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2. Explain why plants do not need a skeletal system.
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Activity # 4: Investigating the skeletons of different animals
Different types of animals have different skeletons. This is because each
different species of animal has a different lifestyle, different needs and
lives in a different environment. They therefore need a skeleton that
allows them to function in their environment.
On the next page there are pictures of ten very different animals. Study
the pictures carefully. Use the internet to find photos of skeletons of these
ten animals then complete the table.
Special requirement on
animal
I am able to jump or hop.
I am able to climb trees and
I eat the leaves of certain
trees.
I am able to fly and hang in
trees
I can fly and soar high
above trees. I can easily
catch snakes, lizards, rats
and mice to eat.
I can walk and run quickly
and can squeeze into small
spaces, like under rocks.
I can swim quickly and
quietly through the water
searching for food.
I can move by sliding over
the ground and in and
around branches of trees.
I can fly but I often find
food by picking it up in mud
that I wade through.
I can walk, but I am best at
climbing and swinging
through trees.
I can swim quickly through
water. I can move on land,
but more slowly.
Feature of skeleton that
satisfies requirement
Animal
name
ACTIVITY 5 : Labelling the major bones of the human skeleton
The human skeleton contains 206 bones. In this activity you will read
descriptions of 16 of the major bones to label them on the diagrams on
the following page. Tick each off as you label it.
Descriptions
 The head is made of many tightly joined bones. The term
cranium is a general name for all of the bones of the head.
On Diagram B, find the arrow that points to the cranium.
Labe1 that arrow "cranium."
 The part of the cranium above the eyes is called the "frontal
bone." On Diagram A. find the arrow that points to the
frontal bone. Label that arrow "frontal bone."
 The scapula, often called the "shoulder blade," is the broad
flat bone of the shoulder. On Diagram B, find the arrow that
points to the scapula. Label that arrow "scapula."
 The longest bone in the arm is the humerus. On Diagram A,
find the arrow that points to the humerus. Label that arrow
"humerus."
 Below the elbow are two long bones. The long bone that
points to the little finger is the ulna. On Diagram A, arrow A
points to the ulna. Label arrow A "ulna."
 The other long bone in the lower arm is called the "radius."
The radius points to the thumb. Find the arrow in Diagram
A that points to the radius. Label that arrow "radius."
 There are eight small bones called the "carpal bones" in the
wrist; they make it possible to rotate the hand in any
direction. Find the arrow in Diagram A that points to the
carpal bones. Label that arrow "carpal bones."
 The short bones in the hand that make the palm are called
the "metacarpals." Arrow B in Diagram A points to the
metacarpals. Label arrow B "metacarpals."
 Each finger is made of three bones; the thumb is made of
only two. The finger and thumb bones are called
"phalanges." In Diagram A, find the arrow that points to the
phalanges. Label that arrow "phalanges."
 The bones that form a cage around the chest are called the
"ribs." On Diagram A, find the arrow that points to the ribs.
Label that arrow "ribs."
 The spinal column, often called the "backbone," is made of
many small bones called "vertebrae" stacked one on top of
another. On Diagram B, find the arrow that points to a
vertebra. Label that arrow "vertebra."
 The longest bone in the body is found in the leg; it is called
the "femur." On Diagram B, find the arrow that points to
the femur. Label that arrow "femur."
 There are two bones in the lower leg; the thicker bone is
called the "tibia." On Diagram B, arrow C points to the tibia.
Label arrow C "tibia."
 The thinner bone in the lower leg is called the "fibula." On
Diagram B, find the arrow that points to the fibula. Label
that arrow "fibula."
 The bone in the foot that makes the heel is called the
"calcaneus." On Diagram B, find the arrow that points to
the calcaneus. Label that arrow "calcaneus."
 The hips are made of three bones; together, they are called
the "pelvic girdle." On Diagram B, find the arrow that points
to the hip. Label that arrow "pelvic girdle."
ACTIVITY 23: Comparing skeletons (A)
Some people keep dogs, cats-even frogs for pets. In many ways, these
skeletons are similar to a human skeleton-especially that of the dog or cat
which are also mammals. Most of the bones in these animals have the
same names as the corresponding bones of the human skeleton.
The diagram below shows some major bones in the dog skeleton:
Activity 6: Comparing skeletons
Use the information above to label some of the major bones in the cat and
frog which follow (Note: one major difference between the skeleton on the
frog & human involves the bones in the lower leg: the frog’s tibia and
fibula are fused to make one bone-called the tibio-fibula bone).
NB: For the cat, label identify bones 1, 3, 4, 6, 7, 10, 11, 12, 18, 20
JOINTS-WHERE ONE BONE MEETS ANOTHER
Activity 7:
(a)
Describe the function of (i) ligaments (ii) cartilage (iii) synovial
fluid in a joint
(b)
Identify an example of a (i) hinge joint (ii) ball and socket (iii)
pivot
(c)
What is the function of an immovable joint?
(d)
Which type of joint allows the greatest degree of movement?