Science 5 SQ Chapter 3 Lesson 7 The Skeletal System and The Muscular System

Science 5 SQ Chapter 3 Lesson 7

The Skeletal System

Multiple Choice

Kick Start: Guess What?

What consist of fused and individual bones

• skeleton

• joint

• skull

• tendon

• spine

Multiple Choice

Kick Start: Guess What?

Area where two bones meet

• skeleton

• joint

• skull

• tendon

• spine

Multiple Choice

Kick Start: Guess What?

a bone enclosing the brain

• skeleton

• joint

• skull

• tendon

• spine

Multiple Choice

Kick Start: Guess What?

connect muscle to bone

• skeleton

• joint

• skull

• tendon

• spine

Multiple Choice

Kick Start: Guess What?

also called the back bone

• skeleton

• joint

• skull

• tendon

• spine

​What Supports and Protects Your Body?

​The skeletal system supports your body and allows you to move

​What do you feel when you touch the top of your head? How about when you press your knees or bend your fingers?

​What you feel are some of your bones that form the framework of your body called the skeletal system.

​

​The skeletal system gives the body structural support and shape. It holds the body as one and allows it to move.

​What parts compose the skeletal system? How does each part help the body in terms of form and movement?

​Do you know that there are around 206 bones in your body?

​

Each bone has a specific size and shape that matches its function. The bones in your body can be divided into two categories.

​Axial Skeleton

​The axial skeleton is composed of 80 bones including the skull, backbone, breastbone, and ribs that protect the delicate organs in the body.

​

​Skull - made up of many bones such as facial bones, ear bones, and a fused, helmetlike structure called cranium that protects the brain.

​

​Spinal column - also called backbone is attached to the skull which is made up of 26 irregularly shaped hollow bones called vertebra that are stacked on top of each other and encloses the spinal cord.

​Axial Skeleton

​The axial skeleton is composed of 80 bones including the skull, backbone, breastbone, and ribs that protect the delicate organs in the body.

​

Sternum - also called breastbone is a long, flat bone at the middle of the chest attached to the ribs.

​

​Ribs - 12 pairs of cagelike curved bones, with 10 pairs attached to the sternum, and two unattached pairs called floating ribs. The sternum and ribs enclose the heart and lungs.

​Appendicular Skeleton

​The appendicular skeleton is composed of 126 bones like the collarbones, shoulder blades, and bones of the arms, legs, and hips that aid movement.

​

​Clavicles - also called collarbones that protrude at the base of your neck.

​

​Scapula - flat, triangular bones also called shoulder blades where clavicles are attached.

​Appendicular Skeleton

Arm bones - composed of humerus (upper arm), and radius and ulna (lower arm). Each hand also has several bones for the fingers and palm. In total, one arm has 30 bones

​Appendicular Skeleton

​The appendicular skeleton is composed of 126 bones like the collarbones, shoulder blades, and bones of the arms, legs, and hips that aid movement.

​

​Hipbone - connects the backbone and the legs. In the middle of the hipbone is a ring called the pelvis.

​Appendicular Skeleton

Leg bones - composed of femur (upper leg), and tibia and fibula (lower leg). Between the upper and lower leg is the patella or kneecap. The foot also has several bones. In total, one leg and foot have 30 bones.

​Appendicular Skeleton

You can bend your knees, twist your arms, nod your head, and do many other things. You can do a lot of movements, thanks to your joints. A joint is formed when two bones meet. You can determine the function of a joint by looking at its structure.

​

Gliding joint - connects the small bones of the wrist to the lower arm that slide over each other.

​Appendicular Skeleton

There are other important parts of the bones that function for protection and aid in movement.

​

Ligaments - made of very thick and elastic material that can stretch and hold the bones together when you move.

​Appendicular Skeleton

Ball-and-socket joints - enable bones to move freely in all directions. The shoulders and hips have ball-and-socket joints.

​Appendicular Skeleton

Saddle joint - allows back and forth motion as well as up and down movement, but does not allow rotational movement like in a ball-and-socket joint.

​

Pivot joint - allows limited movement.

​Appendicular Skeleton

Ball-and-socket joints - enable bones to move freely in all directions. The shoulders and hips have ball-and-socket joints.

​

​Hinge joints - allow only bending and straightening movements. The elbows and knees are examples of hinge joints.

​Appendicular Skeleton

Tendons - connect a muscle to a bone which is also made of tough material.

​What Makes You Move?

​The muscles give the body shape and mass. They support the skeleton and keep it steady. They are also responsible for locomotion. There are about 650 muscles in the body, which are responsible for different types of movement. It is through muscle coordination that you are able to stand, walk, run, and dance.

There are three kinds of muscles in the body: skeletal, smooth, and cardiac muscles. Though they are of different kinds, they share common characteristics. They contract and become short.

They can relax and return to their original form after the contraction.

​Skeletal Muscles

​The muscles that are connected to bones are called skeletal muscles. Their movement is voluntary, that is, they move under your conscious control. They help you move and they also give shape to your body.

​

​Skeletal muscles differ in size and shape. They also differ according to the function.

​Skeletal Muscles

The skeletal muscles work in pairs. When one contracts, the other relaxes. When you bend your arm, your biceps or the upper muscle of your arm contracts and shortens, while the triceps or the lower muscle of your arm relaxes and lengthens. On the other hand, when you put down your arm, the triceps contracts, while the biceps relaxes. The elbow straightens because the triceps pulls the bone of the lower arm.

Smooth Muscles

Smooth muscles are not attached to the bones. They are involuntary muscles because they work automatically. You cannot consciously control the actions of the smooth muscles.

Smooth Muscles

Smooth muscles are found in the walls of blood vessels, helping the blood flow. They are also in the walls of internal organs such as the esophagus and stomach. When you eat, the chewed food is pushed by the rhythmic movement, called peristalsis, of the smooth muscles of the digestive canal. The diaphragm is also an example of a smooth muscle that allows you to breathe even when you are asleep.

Cardiac Muscles

Cardiac muscles are present only in the heart. They move rhythmically, contracting and relaxing alternately. The heart beats at a rate of 70 times per minute or more than 100,000 times a day. It works tirelessly, thanks to the cardiac muscles.

Open Ended

What are the bones that protect the brain and other important organs?

Open Ended

What bones protect the heart and lungs?

Open Ended

What is the largest bone in the body?

Open Ended

Why is the skeletal system important?

Open Ended

What type of muscles are present in the heart and lungs?

Multiple Choice

Which of the following organs has voluntary muscles?

• arms

• legs

• heart

• neck

Task today​

​Performance Task 1: Open the Assignment Tab