Table of ContentsChapter Preview

13.1 Organ Systems and Homeostasis

13.2 The Skeletal System

13.3 The Muscular System

13.4 Machines and the Body

Chapter 13.Preview Questions

1. The position of an object can be changed by

a. pushing on the object.

b. pulling on the object.

c. pushing or pulling on the object.

d. measuring the object’s weight.

Chapter 13.Preview Questions

1. The position of an object can be changed by

a. pushing on the object.

b. pulling on the object.

c. pushing or pulling on the object.

d. measuring the object’s weight.

Chapter 13 Preview Questions

2. The magnitude of a force is the same as

a. its strength.

b. its direction.

c. the distance the force

moves an object.

d. friction produced by the

force.

Chapter 13. Preview Questions

2. The magnitude of a force is the same as

a. its strength.

b. its direction.

c. the distance the force moves an

object.

d. friction produced by the force.

Chapter 13 Preview Questions3. The bigger the change in an object’s motion, the

a. smaller the push or pull required.

b. bigger the push or pull required.

c. more likely the object will move in

more than

one direction.

d. more likely the object will stop

moving.

Chapter 13 Preview Questions

3. The bigger the change in an object’s motion, the

a. smaller the push or pull required.

b. bigger the push or pull required.

c. more likely the object will move in more than

one direction.

d. more likely the object will stop moving.

Chapter 13 Preview Questions

4. When you use your foot to stop a rolling ball, you are

a. pulling on the ball.

b. pushing on the ball.

c. changing the direction in which the

ball rolls.

d. changing the force that started the

ball rolling.

Chapter 13 Preview Questions

4. When you use your foot to stop a rolling ball, you are

a. pulling on the ball.

b. pushing on the ball.

c. changing the direction in which the ball rolls.

d. changing the force that started the ball rolling.

A cat sleeps on one end of a seesaw, while a mouse crouches on the other end. The cat wakes up and walks away. How will the forces acting on the ends

change? How will the forces change if the cat runs across the board toward the mouse?

How do the physical principles of forces and machines relate to the functions of your muscles and skeleton?

Latin Word Origins

Latin Word

Meaning of Latin Word Key Term

in- not

involuntary muscle Type of muscle that is not under a person’s conscious control

Latin Word

Meaning of Latin Word Key Term

ligare to tieligament Connective tissue that holds bones together

Latin Word Origins

Latin Word

Meaning of Latin Word Key Term

porus a tiny opening or hole

osteoporosis A condition in which bones lose minerals, develop larger openings than normal bones, and become weak

Latin Word Origins

Latin Word

Meaning of Latin Word Key Term

resistere to place against

resistance force The force that a lever exerts against an object

Latin Word Origins

Latin Word

Meaning of Latin Word Key Term

voluntas free will

voluntary muscle Type of muscle that is under a person’s conscious control

Latin Word Origins

Apply It!

1. How does the meaning of the Latin word ligere help you to

understand what a ligament is?

Ligare means to tie and a ligament holds bones together.

2. What two key terms in the table come from the Latin word

voluntas? What does this Latin word mean?

Voluntary muscle and involuntary muscle. It means free will.

End of Chapter 13 Preview

Section 13.1 Organ Systems

and Homeostasis

What are the levels of organization in the body?What systems are in the human body, and what are their functions?What is homeostasis?

The 5 Levels of Organization.

The Cell= The Smallest unit

Different cells do different tasks

All cells depend on each other

Cells form tissue

TISSUES

Tissues= cells that work together

Blood tissue

Skin tissue

Bone tissue

The 4 Types of Body Tissues.

Muscle

Makes your body move

Ability to contract

Peristalsis

Your heart

 

Connective

Supports & unites the body from the head to toe

bone

blood

fat

 

Nerve

Caries messages from the brain to the body.

 

Epithelial

Protects your outside surfaces

Lines the mouth, nose, eyes, ears

It is your skin.

 

ORGANS

Organs = tissues that work together

Skin

Heart

Brain

eyes

The Epidermis

In some ways, the skin is the body’s largest organ.

Organ Systems

Organ Systems= organs that work together

Skeletal system

Nervous system

Reproductive system

Organs and Organ Systems

Each organ in your body is part of an organ system, which is a group of organs that work together to perform a major function.

Section 13.2: The Skeletal

System

What are the functions of the skeleton?What role do joints play in the body?What are the characteristics of bone, and how can you keep your bones strong and healthy?

The Skeletal System

The Skeletal System= The bones and the ligaments that hold bones together

There are 206 bones in the body

Your backbone has 26 vertebrae

Bones are light. 20% of your weight comes from your bones

Bones come together at joints

 

 

What the Skeletal System Does

Your skeleton has 5 major functions.

• It provides shape and support

• enables you to move

• protects your organs

• produces blood cells

• stores minerals until your body needs them.

The Skeletal System

 

Joints of the skeleton:

Immovable joints don’t move. They are the bones in the skull and sternum

 

Movable joints= various range of motion

Ball and socket (shoulder and hips)

Pivot joints (neck and head)

Gliding joints (wrist and ankles)

Hinge joint (knee and elbow)

 

Joints of the Skeleton

A joint is a place in the body where two bones come together. Joints allow bones to move in different ways.

Bones—Strong and Living

Bones are complex living structures that undergo growth and development.

Section 13.3: The Muscular

System

What types of muscles are found in the body?Why do skeletal muscles work in groups?

Muscles = Long fibers that run parallel to each other

Always work in pairs (biceps and triceps)

There are 600 in the body

Elephant trunk = 40,000 muscles

Muscle = 40% of our body weight

  

Skeletal:

attach to bone

Connected by tendons

Voluntary muscle

 

Smooth:

Involuntary muscle

Control breathing, heartbeat, digestion

 

Cardiac:

Found only in the heart

The Muscular System

Types of Muscles

Your body has three types of muscle tissue:• skeletal muscle• smooth muscle, and• cardiac muscle.

Muscles at Work

Because muscle cells can only contract, not extend, skeletal muscles must work in pairs. While one muscle contracts, the other muscle in the pair relaxes to its original length.

Section 13.4: Machines and the Body

How are force and work related?How does a lever make work easier?How do bones and muscles function as levers in the body?

Force and Work

A lever is a simple machine that makes lifting heavy objects easier.

Levers

A lever is a ridged bar that is free to pivot, or rotate, on a fixed point.

Levers

Levers are classified according to the location of the fulcrum relative to the input and output forces.

Simple Machines in the Body

Most of the machines in your body are levers that consist of bones and muscles.