44
Table of Contents Chapter Preview 13.1 Organ Systems and Homeostasis 13.2 The Skeletal System 13.3 The Muscular System 13.4 Machines and the Body
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 Questions4. 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 endschange? 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- notinvoluntary 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 againstresistance force The force that a lever exerts against an object
Latin Word Origins
Latin Word
Meaning of Latin Word Key Term
voluntas free willvoluntary 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 unitDifferent cells do different tasksAll cells depend on each other
Cells form tissue
TISSUES
Tissues= cells that work togetherBlood tissueSkin tissueBone tissue
The 4 Types of Body Tissues.
MuscleMakes your body moveAbility to contractPeristalsisYour heart ConnectiveSupports & unites the body from the head to toebonebloodfat
NerveCaries messages from the brain to the body.
EpithelialProtects your outside surfacesLines the mouth, nose, eyes, earsIt is your skin.
ORGANS
Organs = tissues that work togetherSkinHeartBraineyes
The Epidermis
In some ways, the skin is the body’s largest organ.
Organ Systems
Organ Systems= organs that work togetherSkeletal systemNervous systemReproductive 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
SystemWhat 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 bodyYour backbone has 26 vertebraeBones are light. 20% of your weight comes from your bonesBones 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 motionBall 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
SystemWhat types of muscles are found in the body?Why do skeletal muscles work in groups?
Muscles = Long fibers that run parallel to each otherAlways work in pairs (biceps and triceps)There are 600 in the bodyElephant trunk = 40,000 musclesMuscle = 40% of our body weight Skeletal: attach to boneConnected by tendonsVoluntary muscle Smooth: Involuntary muscleControl breathing, heartbeat, digestion Cardiac:Found only in the heart
The Muscular System
Types of MusclesYour 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.
