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

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 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 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 tie ligament 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.