Section 1 Body Organization Objectives: Describe how tissues, organs, and organ systems are related. List 12 organ systems. Identify how organ systems work together to maintain homeostasis. Chapter 22

Homeostasis is the maintenance of a stable internal environment in the body. When you jump into a lake, homeostasis helps your body adapt to the cold water.

Cells Form Tissues A group of similar cells working together forms a tissue. Your body has four main kinds of tissue.

Tissues Form Organs Two or more tissues working together to carry out a specialized function form an organ.

Cells  Tissues  Organs  Organ Systems  Organism

Organs Form Systems Organs that work together make up an organ system. Organ systems work together to maintain homeostasis. Your body has 12 major organ systems.

12 Major Organ Systems

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Systems of the Body and their Functions SystemFunction Integumentary System Your skin, hair, and nails protect underlying tissue. Muscular SystemYour muscles move your bones. Skeletal System Your bones support and protect body parts. Cardiovascular System Your heart pumps blood through your blood vessels to the rest of your body.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Systems of the Body and their Functions SystemFunction Nervous System Receives and sends electrical messages throughout the body. Lymphatic System Returns leaked fluid to blood vessels. It also helps get rid of germs. Digestive System Breaks down the food you eat into nutrients that can be absorbed in your bloodstream. Endocrine System Made of glands that regulate body functions by sending out chemical messages.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Systems of the Body and their Functions SystemFunction Respiratory System Your lungs absorb oxygen and release carbon dioxide. Urinary System Removes wastes from the blood and regulates body fluids. Reproductive System The male reproductive system produces and delivers sperm. Reproductive System The female reproductive system produces eggs and nourishes and shelters the unborn baby.

Section 2 The Skeletal System Objectives: Identify the major organs of the skeletal system. Describe four functions of bones. Describe three types of joints. List three injuries and two diseases that affect bones and joints. Chapter 22

Bones Bones, cartilage, and the connective tissue that holds bones together make up your skeletal system. Bone Structure Bone tissue without any visible open spaces is called compact bone. Bone tissue that has many open spaces is called spongy bone. Bones contain a soft tissue called marrow. (red & yellow) Bone Growth Most bones start out as a flexible tissue called cartilage. Eventually, most cartilage is replaced by bone. (What are 2 exceptions?)

Four Functions of the Skeletal System

Three Kinds of Joints A place where two or more bones meet is called a joint. Joints are held together by ligaments.

Skeletal System Injuries and Diseases Bones may be fractured or broken. Joints may be dislocated. Sprains are caused when ligaments are stretched too far or torn. Arthritis is a disease that causes the joints to swell or stiffen. Osteoporosis is a disease that causes bones to become less dense.

Section 3 The Muscular System Chapter 22 Objectives List three kinds of muscle tissue. Describe how skeletal muscles move bones. Compare aerobic exercise with resistance exercise. Describe two muscular system injuries.

The muscular system is made up of the muscles that let you move. There are three kinds of muscle in your body: Smooth Cardiac Skeletal

Involuntary muscle found in the digestive tract and the walls of the blood vessels is called smooth muscle. Smooth Muscle

Involuntary muscle found in your heart is called cardiac muscle. Cardiac Muscle

Muscle attached to your skeleton for movement is called skeletal muscle. Skeletal muscle can be voluntary or involuntary. Skeletal Muscle

Involuntary-muscle action that is NOT under your control Ex. Smooth muscle & cardiac muscle Voluntary-muscle action that is under your control Skeletal muscles can be both voluntary and involuntary. You can blink your eyes anytime you want to, but your eyes will also blink automatically. Involuntary vs. Voluntary Muscle

3 Kinds of Muscle TypeIllustration Voluntary or Involuntary? Where is it found? Smooth Cardiac Skeletal

Movement Muscles Attach to Bones Tendons are strands of tough connective tissue that connect your skeletal muscles to your bones. Muscles Work in Pairs Skeletal muscles often work in pairs. A muscles that bends part of your body is called a flexor. A muscle that straightens part of your body is an extensor.

Use It or Lose It Resistance Exercise During resistance exercise, people work against the resistance, or weight, of an object to strengthen their skeletal muscles. Aerobic Exercise (using oxygen) Steady, moderately intense activity is called aerobic exercise. It strengthens the heart and increases endurance.

Muscle Injury A strain is an injury in which a muscle or tendon is overstretched or torn. People who exercise too much can inflame their tendons, causing tendonitis. Some people try to make their muscles stronger by taking drugs. These drugs are called anabolic steroids and can cause long- term health problems.

Section 4 The Integumentary System Chapter 22 Objectives List four functions of skin. Describe the two layers of skin. Describe the structure and function of hair and nails. Describe two kinds of damage that can affect skin.

The Integumentary System Consists of skin, hair, and nails Functions of Skin skin protects you by keeping water in your body and foreign particles out of your body nerves in your skin let you feel things regulates your body temperature helps get rid of waste chemicals

Two Main Layers of Skin Skin is the largest organ of your body. Epidermis - outermost layer of skin; most of these cells are dead and filled with a protein called keratin Dermis - thicker layer of skin that lies beneath the epidermis; has many fibers made of a protein called collagen that provide strength and let skin bend without tearing

Hair and Nails A hair forms at the bottom of a tiny sac called a hair follicle. Hair helps protect skin from ultraviolet light and helps regulate body temperature in most mammals. A nail grows from living cells in the nail root at the base of the nail. Nails protect the tips of your fingers and toes.

Skin Injuries Skin is often damaged, but fortunately can repair itself. However, damage to the genetic material in skin cells can cause skin cancer.