Bones, Muscles, and Skin
Body Organization and Homeostasis
The Skeletal System
Diagnosing Bone and Joint Injuries
The Muscular System
The Skin
Table of Contents
Bones, Muscles, and Skin
Section 1: Body Organization and Homeostasis
• Think about how many parts of your body are involved in getting and eating your lunch• Your body is always busy and each part of the body has a specific job to do• All parts of your body work together so smoothly that you don’t even notice it• The smooth function of the body is due to the organization of your body
The levels of organization in the human body consist of cells, tissues, organs, and organ
systems
Bones, Muscles, and Skin
Cells• The cell is the basic unit of structure and function in a living thing• The human body has about 1 trillion cells• Cells cannot be seen without a microscope because they are so small
Bones, Muscles, and Skin
Structures of Cells
• Cell Membrane: outside boundary of the cell
• Nucleus: control center that directs the cell’s activities
• Cytoplasm: Jelly-like clear liquid contained in the cell that contains many structures called organelles
Bones, Muscles, and Skin
Functions of Cells• Cells carry on processes that keep organisms alive
• Ex: Molecules from digested food undergo chemical reactions that release energy for the body’s activities
• Cells grow and reproduce
• Cells get rid of waste products
Bones, Muscles, and Skin
Tissues• A tissue is a group of similar cells that perform the same function• There are 4 basic types of tissues
• Muscle Tissue – contract or shorten, carries out movement
• Nervous Tissue – carries electrical messages back and forth between the brain and other parts of the body
• Connective Tissue – Provides support to the body and connects all its parts (ex: bone, fat, blood)
• Epithelial Tissue – covers surfaces of your body inside and out (ex: skin, lining of organs)
Bones, Muscles, and Skin
Organs and Organ Systems
Organ: Structure that is composed of different types of tissue working together to do the same job (ex: heart, lungs, kidneys, skin)
Organ System: Group of organs that work together to perform a major function (ex: heart is part of the circulatory system)
Bones, Muscles, and Skin - Body Organization and Homeostasis
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.
Bones, Muscles, and Skin
HomeostasisHomeostasis is the body’s tendency to keep an internal balance.
Homeostasis is the process by which an organism’s internal environment is kept stable in spite of changes in the external environment.
Example: Body temperature, blood sugar levels, water levels, blood pressure, etc.
Bones, Muscles, and Skin
Maintaining Homeostasis
Your body has a variety of ways to maintain homeostasis: sweat shiver
Bones, Muscles, and Skin
Stress and HomeostasisSometimes things can happen to disrupt homeostasis. As a result, your heart might beat more rapidly or your breathing may increase. These reactions of your circulatory or respiratory systems are signs of stress.
Stress is the reaction of your body to potentially threatening, challenging or disturbing events.
Adrenaline is a chemical released by your endocrine system in response to stress. Adrenaline gives you a burst of energy and prepares your body to take action.
Your body reacts to Stress!!
Bones, Muscles, and Skin
Outlining
- Body Organization and Homeostasis
Body Organization and Homeostasis
I. CellsA. Structures of CellsB. Functions of Cells
II. TissuesIII. Organs and Organ SystemsIV. Homeostasis
A. Homeostasis in ActionB. Maintaining HomeostasisC. Stress and Homeostasis
An outline shows the relationship between main ideas and supporting ideas. As you read, make an outline about body organization and homeostasis. Use the red headings for the main ideas and the blue headings for the supporting ideas.
Bones, Muscles, and Skin
Cell Specialization
Click the Video button to watch a movieabout cell specialization.
- Body Organization and Homeostasis
Bones, Muscles, and Skin
End of Section:Body
Organization and Homeostasis
Bones, Muscles, and Skin
Section 2: The Skeletal System
• Just like a building you have a framework called a skeleton
• Your skeleton is made up of all the bones in your body (skeletal system)
• You have 206 bones in your body
Bones, Muscles, and Skin - The Skeletal System
What the Skeletal System Does
Your skeleton has five major functions. It provides shape and support, enables you to move, protects your organs, produces blood cells, and stores minerals and other materials until your body needs them.
Bones, Muscles, and Skin
Shape and Support• Your skeleton determines the shape in your body• The backbone (vertebral column) is the center of your skeleton• You have 26 small vertebrae that connect with each other all the way up your vertebral column• Like a beaded necklace, the vertebral column allows your body to move and bend• If your backbone was just one bone, you would not be able to bend
Bones, Muscles, and Skin
Movement and Protection
• Your skeleton allows you to move
• Most bones have muscles attach to allow you to move
• Bones also protect the vital organs in your body
• Ex: the skull protects the brain
Bones, Muscles, and Skin
Production and Storage of Substances• Some of your bones produce substances that your body needs• The long bones of your arms and legs are like factories that make all different kinds of cells• Bones also store minerals like calcium and phosphorous• When the body needs these minerals, the bones release small amounts
Bones, Muscles, and Skin
Immovable and Movable Joints• A joint is a place in the body where two bones come together• Joints allow bones to move in different ways• There are two types of joints in the body
1. Movable: allows wide range of movement, held together by ligaments
• Cartilage is found at the end of bones and protects the bones from rubbing together
2. Immovable: Some joints between bones allow little to no movement like the bones of the skull
Bones, Muscles, and Skin - The Skeletal System
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, Muscles, and Skin - The Skeletal System
Bones—Strong and Living
Bones are complex living structures that undergo growth and development.
Bones, Muscles, and Skin
Bone Structure• Sketch the a long bone such as the femur
Compact Bone: beneath the outer layer is a hard dense layer of the bone called the compact bone. Small canals run through the compact bone that carry blood vessels and nerves
Spongy Bone: a layer of bone just inside the compact bone that is lightweight but strong. Much of spongy bone is found at the ends of long bones and contains red bone marrow which produces red blood cells
Medullary Cavity: carries yellow bone marrow which stores fat
Bones, Muscles, and Skin
Bones Strength
• The structure of bone makes it strong and lightweight
• 20% of a person’s body weight is comprised of bone
• Bones get their strength partly from the minerals like phosphorous and calcium
Bones, Muscles, and Skin
Bone Growth• Bones are alive because they contain cells and tissues like blood and nerves• Bones also form new bone tissue as you grow• Sports contribute to the strength of bones by stimulating new growth in your bone tissue• New bone tissue will form after you have an accident such as breaking a bone in your body
Bones, Muscles, and Skin
Bone Development
• When you were an infant, your skeleton was primarily cartilage
• Over time, most of the cartilage was replaced with bone
Bones, Muscles, and Skin
Taking Care of Your Bones• A combination of a balanced diet and regular exercise are important for a lifetime of healthy bones
1.Diet – A well-balanced diet includes lots of calcium and phosphorous to keep your bones healthy (meats, whole grains, leafy green veggies, and dairy)
2.Exercise – Plenty of exercise provides your bones with the opportunity to stimulate bone growth (weight bearing exercise)
Bones, Muscles, and Skin
Osteoporosis• As people grow older, they lose some of the minerals stored in their body
• This mineral loss can lead to osteoporosis
• Osteoporosis is a condition in which the body’s bones become weak and break easily (hip, spin, wrist)
• Osteoporosis is more common in women than in men
• Regular exercise and a well-balanced diet can help prevent osteoporosis
Bones, Muscles, and Skin
Movable Joints Activity
Click the Active Art button to open a browser window and access Active Art about movable joints.
- The Skeletal System
Bones, Muscles, and Skin
Question Answer
Asking QuestionsBefore you read, preview the red headings. In a graphic organizer like the one below, ask a what or how question for each heading. As you read, write answers to your questions.
What does the skeleton do? The skeleton provides shape and support, helps you to move, protects organs, produces blood cells, and stores minerals and other materials.
How do joints move? Joints can move forward or backward, in a circle, in a rotating motion, and in a gliding motion.
How strong are bones? Bones can absorb more force without breaking than granite or concrete.
What can I do to care for my bones? Eat a well balanced diet and get plenty of exercise.
- The Skeletal System
Bones, Muscles, and Skin
End of Section:The Skeletal
System
Bones, Muscles, and Skin
Procedure X-Rays MRI
Comparing and ContrastingWhen you compare and contrast things, you explain how they are alike and different. As you read, compare and contrast X-rays and MRIs by completing a table like the one below.
Effect on body cells Can cause damage Causes no damage
Types of injuries identified
Bone (fracture and dislocation) Bone and soft tissue
How they workPass through soft tissue and are absorbed by bone; bone shows on film
Magnetic energy causes atoms to vibrate, which forms a pattern that is converted into an image
Cost Low cost High cost
- Diagnosing Bone and Joint Injuries
Bones, Muscles, and Skin
Links on Medical Technology
Click the SciLinks button for links on medical technology.
- Diagnosing Bone and Joint Injuries
Bones, Muscles, and Skin
Section 3: Diagnosing Bone and Joint Injuries
Bones, Muscles, and Skin
Common Skeletal System Injuries
Bones, Muscles, and Skin
Fractures, Dislocations and Sprains
Bones, Muscles, and Skin
Identifying Injuries
Bones, Muscles, and Skin
Treating Injuries
Bones, Muscles, and Skin
End of Section:Diagnosing Bone and Joint Injuries
Bones, Muscles, and Skin
Section 4: The Muscular System
Bones, Muscles, and Skin
Types of Muscle
Bones, Muscles, and Skin
Skeletal Muscle
Bones, Muscles, and Skin
Smooth Muscle
Bones, Muscles, and Skin
Cardiac Muscle
Bones, Muscles, and Skin - The Muscular System
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.
Bones, Muscles, and Skin
Muscles Work in Pairs
Bones, Muscles, and Skin
Muscular Strength and Flexibility
Bones, Muscles, and Skin
When you preview, you look ahead at the material to be read. Preview Figure 15. Then, in a graphic organizer like the one below, write three questions that you have about the diagram. As you read, answer your questions.
Previewing Visuals
Types of Muscle
Q. How does skeletal muscle help my body move?
A. Skeletal muscles are attached to the ends of bones and provide the force to move them.
Q. Where is smooth muscle found?
A. The inside of many internal organs
Q. Why is cardiac muscle considered a special type?
A. It is found only in the heart; it is like smooth muscle because it is involuntary and like skeletal muscle because it is striated.
- The Muscular System
Bones, Muscles, and Skin
Skeletal Muscles
Click the Video button to watch a movieabout skeletal muscles.
- The Muscular System
Bones, Muscles, and Skin
More on Muscle Types
Click the PHSchool.com button for an activityabout muscle types.
- The Muscular System
Bones, Muscles, and Skin
End of Section:The Muscular
System
Bones, Muscles, and Skin
Section 5: The Skin
Bones, Muscles, and Skin
Skin Functions
Bones, Muscles, and Skin - The Skin
The Epidermis
The skin is organized into two main layers: the epidermis and the dermis.
Bones, Muscles, and Skin
The Epidermis Structure and Function
Bones, Muscles, and Skin
The Dermis
Bones, Muscles, and Skin
Caring For Your Skin
Bones, Muscles, and Skin
Sunscreen Ratings
The graph shows how sunscreens with different sun protection factor (SPF) ratings extend the time three people can stay in the sun without beginning to get a sunburn.
- The Skin
Bones, Muscles, and Skin
Sunscreen Ratings
The height of each bar represents the amount of time that person can spend in the sun before burning.
Reading Graphs:
What does the height of each bar in the graph represent?
- The Skin
Bones, Muscles, and Skin
Sunscreen Ratings
20 minutes; 80 minutes; 5 hours
Interpreting Data:
How long can person B stay in the sun without sunscreen before starting to burn? With a sunscreen of SPF 4? SPF 15?
- The Skin
Bones, Muscles, and Skin
Sunscreen Ratings
Person C would need to use SPF 15 sunscreen because SPF 4 would protect the individual for only four hours.
Inferring:
Suppose that person C was planning to attend an all-day picnic. Which sunscreen should person C apply? Use data to support your answer.
- The Skin
Bones, Muscles, and Skin
Sunscreen Ratings
SPF 15 is 3.75 times more effective at preventing sunburn. Calculations: 2.5 hours compared to 40 minutes, or 150 minutes/40 minutes = 3.75; 5 hours compared to 80 minutes, or 300 minutes/80 minutes = 3.75
Calculating:
Which is more effective at preventing a sunburn–a sunscreen with SPF 4 or one with SPF 15? How much more effective is it? Show your work.
- The Skin
Bones, Muscles, and Skin
Sunscreen Ratings
It stands for the level of protection against sunburn—the higher the level, the greater the protection. SPF 4 means a person can safely stay four times as long in the sun; SPF 15—15 times as long.
Drawing Conclusions:
What does the number in the SPF rating stand for? (Hint: Note the length of time each person can stay in the sun without sunscreen, and compare this value to the length of time each can stay in the sun using SPF 4. Then do the same for SPF 15.)
- The Skin
Bones, Muscles, and Skin
Identifying Main IdeasAs you read the section titled “The Body’s Tough Covering,” write the main idea—the biggest or most important idea—in a graphic organizer like the one below. Then write five supporting details. The supporting details give examples of the main idea.
The skin has several important functions.
The skin forms a barrier against disease-causing microorganisms and loss of fluids.
The skin helps the body maintain a steady temperature.
The skin helps to eliminate wastes through perspiration.
The skin contains nerves that gather information about the environment.
Skin cells produce vitamin D that helps your body absorb calcium.
Detail Detail Detail Detail Detail
- The Skin
Main Idea
Bones, Muscles, and Skin
Links on the Skin
Click the SciLinks button for links on the skin.
- The Skin
Bones, Muscles, and Skin
End of Section:The Skin
Bones, Muscles, and Skin
Graphic Organizer
Muscles
Voluntary muscles
can be
include
Involuntary muscles
include
Smooth muscles
Cardiac muscles
Skeletal muscles
Bones, Muscles, and Skin
End of Section:Graphic Organizer