Table of Contents – pages iii

Unit 1: What is Biology?Unit 2: EcologyUnit 3: The Life of a CellUnit 4: GeneticsUnit 5: Change Through TimeUnit 6: Viruses, Bacteria, Protists, and FungiUnit 7: PlantsUnit 8: InvertebratesUnit 9: VertebratesUnit 10: The Human Body

Unit 1: What is Biology?

Chapter 1: Biology: The Study of LifeUnit 2: Ecology Chapter 2: Principles of Ecology Chapter 3: Communities and Biomes Chapter 4: Population Biology Chapter 5: Biological Diversity and ConservationUnit 3: The Life of a Cell Chapter 6: The Chemistry of Life Chapter 7: A View of the Cell Chapter 8: Cellular Transport and the Cell Cycle Chapter 9: Energy in a Cell

Unit 4: Genetics

Chapter 10: Mendel and Meiosis

Chapter 11: DNA and Genes

Chapter 12: Patterns of Heredity and Human Genetics

Chapter 13: Genetic Technology

Unit 5: Change Through Time Chapter 14: The History of Life Chapter 15: The Theory of Evolution Chapter 16: Primate Evolution Chapter 17: Organizing Life’s Diversity

Unit 6: Viruses, Bacteria, Protists, and Fungi

Chapter 18: Viruses and Bacteria

Chapter 19: Protists

Chapter 20: Fungi

Unit 7: Plants

Chapter 21: What Is a Plant?

Chapter 22: The Diversity of Plants

Chapter 23: Plant Structure and Function

Chapter 24: Reproduction in Plants

Unit 8: Invertebrates

Chapter 25: What Is an Animal?

Chapter 26: Sponges, Cnidarians, Flatworms, and

Roundworms

Chapter 27: Mollusks and Segmented Worms

Chapter 28: Arthropods

Chapter 29: Echinoderms and Invertebrate

Chordates

Unit 9: Vertebrates Chapter 30: Fishes and Amphibians

Chapter 31: Reptiles and Birds

Chapter 32: Mammals

Chapter 33: Animal Behavior

Unit 10: The Human Body

Chapter 34: Protection, Support, and Locomotion

Chapter 35: The Digestive and Endocrine Systems

Chapter 36: The Nervous System

Chapter 37: Respiration, Circulation, and Excretion

Chapter 38: Reproduction and Development

Chapter 39: Immunity from Disease

The Human Body

Protection, Support, and Locomotion

The Digestive and Endocrine System

The Nervous System

Respiration, Circulation, and Excretion

Reproduction and Development

Immunity from Disease

Chapter 34 Protection, Support, and Locomotion

34.1: Skin: The Body’s Protection

34.1: Section Check

34.2: Bones: The Body’s Support

34.2: Section Check

34.3: Muscles for Locomotion

34.3: Section Check

Chapter 34 Summary

Chapter 34 Assessment

What You’ll Learn

You will interpret the structure and functions of the integumentary system.

You will identify the functions of the skeletal system.

You will classify the different types of muscles in the body.

Chapter 32

• Compare the structures and functions of the epidermis and dermis.

Section Objectives:

• Identify the role of the skin in responding to external stimuli.

• Outline the healing process that takes place when the skin is injured.

32.1

• Skin, the main organ of the integumentary (inh TE gyuh MEN tuh ree) system, is composed of layers of the four types of body tissues: epithelial, connective, muscle, and nervous.

• Epithelial tissue, found in the outer layer of the skin, functions to cover surfaces of the body.

Structure and Functions of the Integumentary SystemStructure and Functions of the Integumentary System

32.1

• Connective tissue, which consists of both tough and flexible protein fibers, serves as a sort of organic glue, holding your body together.

• Muscle tissues moves parts of the body. In the skin, muscle interacts with hairs on the skin to respond to stimuli, such as cold and fright.


32.1

• Nervous tissue helps us detect external stimuli, such as pain or pressure.

Epidermis

Dermis


32.1

• Skin is composed of two principal layers—the epidermis and dermis.


Epidermis

Dermis

32.1

Epidermis: The outer thinner layer of skinEpidermis: The outer thinner layer of skin

32.1

• The top layer of cells, although dead & flattened, serves an important function as they contain a protein called keratin (KER uh tun).

• Keratin helps to waterproof and protect the living cell layers underneath from exposure to bacteria, heat, and chemicals.


32.1

• The interior layer of the epidermis contains living cells that continually divide by mitosis to replace the dead cells.

• Some of these cells contain melanin, a pigment that colors the skin and helps protect body cells from damage by solar radiation. Even though the # of melanin-producing cells is about the same in each person, the amt. of melanin produced per cell varies, resulting in different colors of skin.

• Every four weeks, all cells of the epidermis are replaced by new cells.


32.1

• The epidermis on the fingers and palms of your hands, and on the toes and soles of your feet, contain ridges and grooves that are formed before birth.

• These epidermal ridges are important for gripping as they increase friction.


32.1

Dermis: The inner thicker layer of skin Dermis: The inner thicker layer of skin

32.1

The thickness of this layer varies depending on the function of that body part.

The SkinThe SkinOil glands

Hair

Sweatglands

32.1

The fat layer is below the dermis. It functions to store E, provide insulation, & acts a shock absorber.

• One function of skin is to help maintain homeostasis by regulating your internal body temperature.

• Erector pili muscle & goose bumps – forma a layer of insulation to prevent heat loss.

• When your body temperature rises, the many small blood vessels in the dermis dilate, blood flow increases, and body heat is lost by radiation.

Functions of the integumentary systemFunctions of the integumentary system32.1

• Primary function is PROTECTION

• When you are cold, the blood vessels in the skin constrict and heat is conserved.

• Glands in the dermis produce sweat in response to an increase in body temperature.

Functions of the integumentary systemFunctions of the integumentary system

• As sweat evaporates, water changes state from liquid to vapor and heat is lost.

32.1

• Keeps the hair moist


• Keeps the skin soft & pliable

32.1

• Inhibits the growth of some bacteria

3 functions of the oil produced by the skin:

• Skin also functions as a sense organ.

• Nerve cells in the dermis receive stimuli from the external environment and relay information about pressure, pain, and temperature to the brain.


32.1

• When exposed to ultraviolet light, skin cells produce vitamin D, a nutrient that aids the absorption of calcium into the bloodstream.


32.1

• Another function of the skin is to maintain a chemical balance of certain substances, such as Vitamin D.

Functions of the integumentary systemFunctions of the integumentary system• Cuts or other openings in the skin surface

allow bacteria to enter the body, so they must be repaired quickly.

32.1

• When the epidermis sustains a mild injury, such as a scrape, the deepest layer of epidermal cells divide to help fill in the gap left by the abrasion.

Skin Injury and HealingSkin Injury and Healing

• If, however, the injury extends into the dermis, where blood vessels are found, bleeding usually occurs.

32.1

• Burns can result from exposure to the sun or contact with chemicals or hot objects.

• Burns are rated according to their severity.


32.1


• First-degree burns, such as a mild sunburn, involve the death of epidermal cells and are characterized by redness and mild pain.

• First-degree burns usually heal in about one week without leaving a scar.

32.1

• Second-degree burns involve damage to skin cells of both the epidermis and the dermis and can result in blistering and scarring.


• The most severe burns are third-degree burns, which destroy both the epidermis and the dermis.

• With this type of burn, skin function is lost, and skin grafts may be required to replace lost skin.

32.1

• As people get older, their skin changes.


• It becomes drier as glands decrease their production of lubricating skin oils—a mixture of fats, cholesterol, proteins, and inorganic salts.

32.1


• Wrinkles may appear as the elasticity of the skin decreases.

32.1

Question 1What part of the skin responds to external stimuli such as heat and pressure?

D. muscle tissue

C. connective tissue

B. nervous tissue

A. epithelial tissue

32.1

The answer is B, nervous tissue.

Nerve endings

32.1

Question 2

Why is your skin considered an organ?

Answer

Skin is composed of cells and tissues. A group of tissues that work together to perform a specialized function are called an organ.

32.1

Question 3The thicker portion of skin that is composed of blood vessels, nerves, nerve endings, hair follicles, sweat glands, and oil glands is called the _______.

D. fat tissue

C. epidermis

B. subcutaneous layer

A. dermis

32.1

The answer is A, dermis.

32.1

Section Objectives

• Describe how bone is formed.

• Compare the different types of movable joints.

• Identify the structure and functions of the skeletal system.

32.2

• The adult human skeleton contains about 206 bones.

Skeletal System Structure


• Its two main parts are shown.

32.2



32.2

• In vertebrates, joints are found where two or more bones meet.

Joints: Where bones meetJoints: Where bones meet

• Most joints facilitate the movement of bones in relation to one another.

• The joints of the skull, on the other hand, are fixed joints, as the bones of the skull don’t

move.

32.2

• Joints are often held together by ligaments.


• A ligament is a tough band of connective tissue that attaches one bone to another.

• In movable joints, the ends of bones are covered by cartilage.

• This layer of cartilage allows for smooth movement between the bones.

32.2

• In addition, joints such as those of the shoulder and knee have fluid-filled sacs called bursae located on the outside of the joints.


• The bursae act to decrease friction and keep bones and tendons from rubbing against each other.

32.2

• Forcible twisting of a joint, called a sprain, can result in injury to the bursae, ligaments, or tendons.


• A sprain most often occurs at joints with large ranges of motion such as the wrist, ankle, and knee.

• Tendons, which are thick bands of connective tissue, attach muscles to bones.

32.2

• One common joint disease is arthritis, an inflammation of the joints.


• One kind of arthritis results in bone spurs, or outgrowths of bone, inside the joints.

• Such arthritis is especially painful, and often limits a person’s ability to move his or her joints.

32.2

• Bones are composed of two different types of bone tissue: compact bone and spongy bone.

Compact and spongy boneCompact and spongy bone

Spongy bone

Marrow cavity

Compact bone

VeinArtery

Humerus

Periosteum

32.2


Spongy bone

Marrow cavity

Compact bone

VeinArtery

Humerus

Periosteum

• Surrounding every bone is a layer of hard bone, or compact bone.

32.2

• Running the length of compact bone are tubular structures known as osteon or Haversian (ha VER zhen) systems.

• Compact bone is made up of repeating units of osteon systems.

Blood vessel

Membrane

Compactbone

Marrowcavity

Cartilage

Spongybone


32.2

• Living bone cells, or osteocytes (AHS tee oh sitz), receive oxygen and nutrients from small blood vessels running within the osteon systems.

CapillaryOsteon systems

VeinArterySpongy bone


32.2

• Compact bone surrounds less dense bone known as spongy bone because, like a sponge, it contains many holes and spaces.

Blood vessel

Membrane

Compactbone

Marrowcavity

Cartilage

Spongybone


32.2

• The skeleton of a vertebrate embryo is made of cartilage.

Formation of BoneFormation of Bone

• By the ninth week of human development, bone begins to replace cartilage.

Cartilage

Bone

Blood supply

Marrow cavity

32.2

Cartilage

Bone

Blood supply

Marrow cavity


• Blood vessels penetrate the membrane covering the cartilage and stimulate its cells to become potential bone cells called osteoblasts.

32.2

• These potential bone cells secrete a protein called collagen in which minerals in the bloodstream begin to be deposited.


Marrow cavity

32.2


• The deposition of calcium salts and other ions hardens the newly formed bone cells, now called osteocytes.

Marrow cavity

32.2

• Your bones grow in both length and diameter.

Bone growthBone growth

• Growth in length occurs at the ends of bones in cartilage plates.

• Growth in diameter occurs on the outer surface of the bone.

• After growth stops, bone-forming cells are involved in repair and maintenance of bone.

32.2

• The primary function of your skeleton is to provide a framework for the tissues of your body.

Skeletal System FunctionsSkeletal System Functions

• The skeleton also protects your internal organs, including your heart, lungs, and brain.

32.2

• Muscles that move the body need firm points of attachment to pull against so they can work effectively.


• The skeleton provides these attachment points.

32.2

• Bones also produce blood cells.

• Red marrow—found in the humerus, femur, sternum, ribs, vertebrae, and pelvis—is the production site for red blood cells, white blood cells, and cell fragments involved in blood clotting.


32.2


• Yellow marrow, found in many other bones, consists of stored fat.

Yellow bone marrow

32.2

• Your bones serve as storehouses for minerals, including calcium and phosphate.

Bones store mineralsBones store minerals

• Calcium is needed to form strong, healthy bones and is therefore an important part of your diet. It is also needed for muscle contractions & nerve impulses.

32.2

• Bones tend to become more brittle as their composition changes with age.

• For example, a disease called osteoporosis (ahs tee oh puh ROH sus) involves a loss of bone volume and mineral content, causing the bones to become more porous and brittle.

Bone injury and diseaseBone injury and disease

32.2

• When bones are broken a doctor moves them back into position and immobilizes them with a cast or splint until the bone tissue regrows.

Bone injury and diseaseBone injury and disease

32.2

What type of joint is illustrated in this image?

Question 1

D. gliding

C. pivot

B. hinge

A. ball and socket

32.2

The answer is C. Pivot joints allow bones to twist around each other.

32.2

Where, on the body, would you find bursae?

Question 2

D. pelvis

C. shoulder

B. hands

A. skull

32.2

The answer is C, shoulder. Bursae are fluid-filled sacs located on the outside of the joints. They act to decrease friction.

32.2

What disease causes the bones to become brittle?

Question 3

D. phosphate deficiency C. a sprain B. osteoporosis A. arthritis

The answer is B. Osteoporosis involves a loss of bone volume and mineral content.

32.2

• Classify the three types of muscles.

Section Objectives:

• Analyze the structure of a myofibril.

• Interpret the sliding filament theory.

32.3

• Nearly half of your body mass is muscle.Three Types of Muscles

• A muscle consists of groups of fibers, or cells, bound together.

• One type of tissue, smooth muscle, is found in the walls of your internal organs (digestive organs, reproductive organs, etc.) and blood vessels. Smooth muscle cells only have one nucleus.

Smooth muscle fiber

Nucleus

32.3

• The most common function of smooth muscle is to squeeze (contract) with slow, prolonged contractions., exerting pressure on the space inside the tube or organ it surrounds in order to move material through it.

Three Types of Muscles

Large and Small Intestine

32.3


Large and Small Intestine

• Because contractions of smooth muscle are not under conscious control, smooth muscle is considered an involuntary muscle.

32.3

• Another type of involuntary muscle is the cardiac muscle, which makes up your heart. It has stripes on it and is thus said to be striated.


• Cardiac muscle fibers are interconnected and form a network that helps the heart muscle contract efficiently.

Cardiac muscle fiber

Striation

Nucleus

32.3

• Cardiac muscle is found only in the heart and is adapted to generate and conduct electrical impulses necessary for its powerful and efficient rhythmic contractions.


Heart

• Like smooth muscle, cardiac muscle has only one nucleus and is also involuntary.

32.3

• The third type of muscle tissue, skeletal muscle, is the type that is attached to and moves your bones.


Skeletalmuscle fiber

Nucleus

Striation • Like skeletal muscle, it is striated. It undergoes short, strong contractions.

32.3


• A muscle that contracts under conscious control is called a voluntary muscle.

Skeletal Arm Muscle

Each cell has many nuclei and is thus said to be multinucleated.

32.3

Skeletal Muscle Contraction The majority of skeletal muscles work in opposing pairs.

32.3

Skeletal Muscle Contraction

• Muscle tissue is made up of muscle fibers, which are actually just very long, fused muscle cells.

• Each fiber is made up of similar units called myofibrils (mi oh FI brulz).

32.3

Skeletal muscleTendon

Bone

Bundles of muscle fibers

Myosin

ActinFilaments

Sarcomere

Myofibril


• Myofibrils are themselves composed of even smaller protein filaments that can be either thick or thin.

32.3


Bone


Myosin

ActinFilaments

Sarcomere

Myofibril


• The thicker filaments are made of the protein myosin, and the thinner filaments are made of the protein actin.

32.3


Bone


Myosin

ActinFilaments

Sarcomere

Myofibril


• Each myofibril can be divided into sections called sarcomeres (SAR kuh meerz), the functional units of muscle.

32.3

Click image to view movie.


32.3

• The sliding filament theory currently offers the best explanation for how muscle contraction occurs.


• The sliding filament theory states that, when signaled, the actin filaments within each sarcomere slide toward one another, shortening the sarcomeres in a fiber and causing the muscle to contract.

32.3



Bone


Myosin

ActinFilaments

Sarcomere

Myofibril

Muscle structure

Nerve signal

32.3


32.3

• Muscle strength does not depend on the number of fibers in a muscle.

Muscle Strength and Exercise

• Rather, muscle strength depends on the thickness of the fibers and on how many of them contract at one time.

32.3

• Regular exercise physically stresses muscle fibers slightly; to compensate for this added workload, the fibers increase in diameter by adding layers of protein & myofibrils.


• Muscle cells are continually supplied with ATP from both aerobic and anaerobic processes.

32.3

• When an adequate supply of oxygen is unavailable, such as during vigorous activity, an anaerobic process - specifically lactic acid fermentation—becomes the primary source of ATP production.

Muscle Strength and Exercise • Muscles are supplied with ATP by one of 2

methods – aerobic processes are at work when there is an adequate supply of oxygen available.

32.3

• During vigorous exercise, lactic acid builds up in muscle cells.

Blood Lactic Acid Levels During Exercise

Blo

od la

ctic

aci

d

Work rate

Shift toward anaerobic process


32.3

• As the excess lactic acid is passed into the bloodstream, the blood becomes more acidic, rapid breathing is stimulated, and cramping can occur.

• As you catch your breath following exercise, adequate amounts of oxygen are supplied to your muscles and lactic acid is broken down.


32.3

Skeletal Muscle Strength

• Slow-twitch muscles

• Slow-twitch muscle fibers have more endurance than fast-twitch muscle fibers.

• They contain myoglobin, a respiratory molecule that stores oxygen and serves as an oxygen reserve.

32.3

Fast-Twitch Muscles

• Fast-twitch muscle fibers fatigue easily but provide great strength for rapid, short movements.

They rely on anaerobic metabolism, which causes a buildup of lactic acid.

32.3

What is the difference between cardiac muscle and smooth muscle?

Question 1

Cardiac Muscle Smooth Muscle

32.3

Cardiac muscle is striated and found only in the heart. It is designed to generate and conduct electrical impulses. Smooth muscle is found in the walls of your internal organs. It is nonstriated.

Cardiac Muscle Smooth Muscle

32.3

What can you conclude about oxygen consumption during exercise by looking at this graph?

Question 2

Oxygen Consumption During Exercise

Work rate

Rat

es o

f ox

ygen

co

nsu

mpt

ion

32.3

As an individual increases the intensity of his/her workout, the need for oxygen also increases in predictable increments.

Oxygen Consumption During Exercise

Work rate

Rat

es o

f ox

ygen

co

nsu

mpt

ion

32.3

What is the sliding filament theory?

Question 3

Answer

The sliding filament theory explains how muscles contract. It states that when signaled, the actin filaments within each sarcomere slide toward one another, shortening the sarcomeres in a fiber, causing the muscle to contract.

32.3

• Skin is composed of the epidermis and dermis, with each layer performing various functions.

Skin: The Body’s Protection

• Skin regulates body temperature, protects the body, and functions as a sense organ.

• Skin responds to injury by producing new cells and signaling a response to fight infection.

• The skeleton is made up of the axial and appendicular skeletons.

Bones: The Body’s Support

• Joints allow movement between two or more bones where they meet.

• Osteocytes are living bone cells.

• Bones are formed from cartilage as a human embryo develops.

Bones: The Body’s Support

• The skeleton supports the body; provides a place for muscle attachment, protects vital organs, manufactures blood cells, and serves as a storehouse for calcium and phosphorus.

• There are three types of tissue: smooth, cardiac, and skeletal. Smooth muscle lines organs, contracting to move materials through the body. Cardiac muscle contracts rhythmically to keep the heart beating. Skeletal muscle is attached to bones and contracts to produce body movements.

Muscles for Locomotion

• Muscle tissue consists of muscle fibers, which can be divided into smaller units called myofibrils.

Muscles for Locomotion

• Muscles contract as filaments within the myofibrils slide toward one another.

Question 1

What does muscle strength depend on?

Answer

Muscle strength depends on the thickness of the muscle fibers and on how many of them contract at one time.

Question 2

Study the diagram. What part of the skin is number two referring to?

D. sweat pore

C. muscle

A. hair follicle

1 4 2

3 B. vein

The answer is A, hair follicle.

1 4 2

3

Question 3

What becomes the primary source of ATP production for your muscles during heavy exercise?

D. lactic acid fermentation

C. myosin

B. muscle contraction

A. cellular respiration

The answer is D, lactic acid fermentation.

Blood Lactic Acid Levels During Exercise

Blo

od la

ctic

aci

d

Work rate

Shift toward anaerobic process

Question 4

What type of joint is used when you kick a soccer ball?

D. gliding

C. pivot

B. hinge

A. ball and socket

The answer is B. Hinge joints are found in your knees and toes, both of which you use when you kick a soccer ball.

Hinge

Question 5

What type of burn results in damage to the dermis and epidermis as well as blistering and scaring?

D. fourth-degree

C. third-degree

B. second-degree

A. first-degree

The answer is B. Second degree burns can cause damage to the dermis and epidermis, but skin function is not lost.

Question 6

What are newly formed bone cells called?

D. spongy bone

C. compact bone

B. osteoblasts

A. osteocytes

The answer is A, osteocytes.

CapillaryOsteon systems

VeinArterySpongy bone

Question 7

When does bone begin to replace cartilage in a human embryo?

D. at the 9th week

C. at birth

B. at the 12th week

A. during the last trimester

The answer is D. Blood vessels penetrate the membrane covering the cartilage and stimulate its cells to become potential bone cells.

Photo CreditsPhoto Credits

• PhotoDisc

• Corbis

• Latent Image

• Tim Courlas

• KS Studios

• Digital Stock

• Doug Martin

• Alton Biggs

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