How do cells work together to form organs? What are some of the organ systems in your body? Watch this video to learn more.
Lesson B3: Cells Working Together as Organs
Figure B.1.3.1 – Skin protects the human body.
Figure B.1.3.2 – Some animals have an outer layer of scales.
Figure B.1.3.3 – Human skin has three layers.
Reading and Materials for This Lesson
Science in Action 8
Reading: Pages 93–97
Materials:
Paper, water-based ink pad, pencil, soap, sink, cooked chicken bones, magnifying glass (optional), plate or bowl, glass jar with lid, white vinegar, disposable gloves, electric kettle, water, glass mug, gelatin powder, corn syrup, teaspoon measure,
cup measure, spoon.
The Skin You're In
 You
might be surprised to learn that the largest body organ is skin! Skin is part of the integumentary organ system. The integumentary system protects the body’s insides from physical damage, invading microbes, dehydration, overheating, and freezing.
Some animals have scales, feathers, and fur as part of their integumentary system.
Skin is made of three layers. The outermost layer of skin is called the epidermis. The outer layer of epidermis, the skin that you see, is made of dead skin cells. Dead skin cells constantly fall off your body and are replaced with new ones. You lose
4 kg of skin cells every year!
Underneath the epidermis is the dermis. The dermis contains nerves that sense temperature and touch. The dermis also contains oil glands and sweat glands. Most people don’t like having oily skin, but the oil made by your oil glands helps make your
skin waterproof. Sweat glands release sweat, which helps cool your body when it overheats.
The deepest layer of skin is the hypodermis, which is made of fat. Fat is an insulator that helps keep your body warm. The hypodermis also contains tiny follicle tubes that hair grows from.
Watch More
Thick Skin
Watch this video to learn more about how skin protects your body.
Why do people have different skin colours? Watch this video to learn more about how the pigment melanin causes skin colour.
How does hair grow and why do some people become bald? Watch this video to learn more about hair follicles in the skin.
Some scientists are working on making artificial skin that can sense touch and temperature, just like real skin. Watch this video to learn more about artificial skin technology.
Figure B.1.3.4 – A spiraling fingerprint is called a whorl.
Figure B.1.3.5 – A folded round fingerprint is a loop.
Figure B.1.3.6 – Arched fingerprints form a gentle ridge.
Fingerprints
If you look closely at the surface of your fingers, you will see a curved pattern of tiny ridges and valleys. These are your fingerprints. Fingerprints are an adaptation that create friction so objects are easier to pick up. Every person has different
fingerprints. Even identical twins have different fingerprints!
Fingerprints are useful in some situations. Your fingers leave fingerprints behind on smooth surfaces. Police detectives use a special dusting powder to find fingerprints at crime scenes. They can match these fingerprints to a suspect’s fingerprints.
New security technologies, such as locks and cell phones, use fingerprint scanners to identify a person.
Watch More
Forming Fingerprints
Watch this video to learn more about how fingerprints form on hands.
This video explains different fingerprint shapes.
Try It!
Fingerprinting Yourself
Try this fun activity to examine and compare fingerprint patterns.
Materials:
Paper
Water-based ink pad
Pencil
Soap
Sink
Instructions:
Press one of your thumbs into an inkpad. If you don’t have an inkpad, coloring with washable marker on your skin will also work.
Press your inked thumb down onto a piece of paper.
Repeat steps 1 and 2 for the other four fingers on the same hand.
Look carefully at your fingerprints. Do they show whorl, loop, or arch patterns? Do all your fingers have the same pattern, or is each finger different?
Wash your hands.
Find two willing friends or family members and collect their fingerprints. Compare your fingerprints with their fingerprints. What similarities and differences do you notice in the fingerprints?
Figure B.1.3.7 – The skeletal system provides support for the human body.
Figure B.1.3.8 – The insides of bones contain bone marrow.
Skeletal System
Most people see bones when they eat meat, or in a museum, like dinosaur bones. Seeing dead bones might make you think that bones are similar to rocks. However, living bones are not rocks. Bones do contain hard minerals, but they are made of living
bone cells.
Figure B.1.3.9 – Bones are made of bone cells.
The inside of a bone contains a spongy material with lots of tiny holes, called bone marrow. Bone marrow makes blood cells. Bone marrow is surrounded with compact bone, which is made of hard minerals, including calcium, for support. Getting enough
calcium in your diet is important to maintain strong bones. Green leafy vegetables and dairy products contain lots of calcium. The outer bone surface contains blood vessels that carry nutrients to bones.
If a person breaks a bone, the bone can heal. Doctors put a cast over a broken bone to make sure that the broken bone pieces are close together. The body then makes new bone cells that reconnect the two broken bone pieces.
Some parts of the body, like the ears and the nose, do not contain bone. These body parts are supported by a material called cartilage. Cartilage is softer and more flexible than bone. For this reason, cartilage is also found in the joints that
connect bones.
Watch More
Skeletons Aren't Just For Halloween Anymore
This video will teach you more about bone structure and how broken bones heal.
Watch this video to learn the names of some of the bones in your body.
Watch this video to learn more about cartilage.
Try It!
Bendy Chicken Bone
Try this experiment to examine the structure of a chicken bone.
Materials:
Cooked chicken bones
Magnifying glass (optional)
Plate or bowl
Glass jar with lid
White vinegar
Disposable gloves
Instructions:
Select a medium-sized chicken bone. With your hands, carefully break the bone in half.
Observe the interior of the bone. Use a magnifying glass to look closer. You should see a white or grey hard outer surface, which is the mineral compact bone. The red or brown soft material in the middle is the bone marrow.
Fill the glass jar halfway full of vinegar.
Place several chicken bones in the jar of vinegar. The vinegar should completely cover the bones. If not, add more vinegar until the bones are completely covered.
Put a lid on the jar and place it in the fridge for a week.
Wearing gloves, open the jar and take out a chicken bone.
Try bending the bone. What do you observe?
Watch this video to see this experiment and its results:
Questions:
Think about the following question very carefully. Then, type or write your answer. After you have your answer, click the question for feedback.
Minerals form the compact bone layer, which makes bones hard. Vinegar dissolved the minerals in the compact bone layer. The bone material left behind is the inner spongy soft bone marrow, which could bend.
Figure B.1.3.10 – Organ donations are transported in ice coolers.
Figure B.1.3.11 – Many people agree to donate their organs when they die.
Organ Transplants
Sometimes people’s organs stop working properly. Organ transplants can save people with failing organs. Many organ donors are people that die suddenly, such as from a brain injury in a car collision. In these situations, the person is dead, but
many of their organs are not damaged, and can be transplanted into another person. The working organs are cut out of the donor’s body and are transported in a cooler to the hospital where the recipient waits.
Some organ donors are living donors. Living organ donors give part of a healthy body organ to a patient in need of an organ. Living organ donations can be part of a liver, lung, or pancreas. A very common living donation is the gift of one kidney
to a person whose two kidneys have failed.
Adults can choose to donate their organs if they die. To make their wishes for organ donation known, adults need to sign an organ donation card. Click here for
more information about organ donation in Alberta.
Watch More
The Gift of Life
Organ donations are usually transported in ice coolers. Organs need to be transported quickly before they freeze. A newly-invented machine can lengthen the time available for organ transportation. Watch this video to learn more about this invention.
WARNING for
the squeamish: The next video shows real beating human hearts.
Connections
Figure B.1.3.12 – 3D printers are a new technology that can be used to manufacture objects.
Figure B.1.3.13 – Scientists are experimenting with using 3D printers to print body organs.
Connections – Technology >> Printed Body Parts
3D printers are used to print three-dimensional objects that are designed on a computer. 3D printers can create very precise objects as they print layers of melted plastic, metal, or food.
This technology is useful for making detailed machine parts, toys, or even shaped food. Because of their precision, some scientists are starting to use 3D printers to make body parts! Researchers grow human cells, mix the cells in a gel, and print
out layers of the gelled cells to make a 3D printed body part.
Watch More
Printed Body Parts
How does 3D printing work? Watch this video to learn more.
This video gives a good overview of some different body parts that are being printed with 3D printers.
3D printed organs could reduce the number of people dying while they wait for an organ transplant. Watch this video to learn more about a Canadian scientist who is researching 3D printed organs.
Watch this video to see 3D printing of body parts.
Figure B.1.3.14 – When you are sick, your body produces extra mucus.
Figure B.1.3.15 – The eye is covered with a layer of mucus.
Mucus. It's Not What You Think!
Mucus is a thick, wet substance that helps keep your body healthy. Mucus contains protein strands, sugars, and water. Body parts that connect the inside of the body to the outer environment are coated with mucus. These body parts include the digestive
system, nose, mouth, eyes, and lungs.
Mucus traps invading microbes and particles like dust, bacteria, and viruses, that harm the body. When you are sick, your body produces extra mucus to get rid of the invading microbes. That is why a runny nose and stuffy sinuses are cold and flu
symptoms – they are the result of your body producing more mucus to get rid of germs!
Watch More
Mucus: In Sickness and In Health
Watch this video to learn more about how mucus helps your body stay healthy.
Try It!
Make Fake Mucus
Try this experiment to make fake mucus, which has a similar consistency to real mucus. The gelatin in this experiment is a type of protein.
Materials:
Electric kettle
Water
Glass mug
Gelatin powder
Corn syrup
Teaspoon measure
Cup measure
Spoon
Safety Warning
This
activity involves hot fluids. It must be completed with the supervision
of an adult. DO NOT attempt this activity by yourself.
Hot fluids can burn you or others if you are not careful. Take care when pouring hot fluids.
Instructions:
Boil water in the electric kettle.
Fill the glass mug half-full with boiling water.
Add 4 teaspoons of gelatin to the boiling water and stir.
Add ¼ cup of corn syrup to the mug and stir.
As the mixture starts to cool, slowly add more hot water and stir it in with the spoon. The mixture should be thick, but able to flow.
Let the fake mucus mixture cool completely.
Use the spoon to observe the texture of the fake mucus. Touch it with your fingers if you like.
Watch this video to see this experiment and its results:
Questions:
Think about the following question very carefully. Then, type or write your answer. After you have your answer, click the question for feedback.
Mucus is a mixture of protein, sugars, and water. The fake mucus contained a protein from gelatin, sugars from corn syrup, and water.
Connections
Figure B.1.3.16 –
Allergies can be triggered by foods or substances found in your surroundings.
Figure B.1.3.17 – Medication like epi pens are used for serious allergic reactions.
Connections – Health >> Allergies
People have allergies when their body’s immune system overreacts to certain substances. Common allergens include pollen, insect venom, foods, and animals. When a person with an allergy encounters an allergen, their immune system creates substances
called histamines. Histamines cause sneezing, a runny nose, and itchy eyes.
Some allergies are mild, such as being allergic to pollen and cat dander. These allergic reactions can usually be managed with drugstore anti-histamine medications. However, some allergies are life-threatening. Peanut, insect sting, and shellfish
allergies can cause a severe reaction called anaphylactic shock. Some symptoms of anaphylactic shock include skin hives, vomiting, and a swelled throat which causes breathing problems.
A substance called epinephrine, or adrenaline, is a medication to treat anaphylactic shock. Epinephrine is a natural hormone in the body, but it also acts as a severe allergy medication. People with severe allergies usually carry epinephrine in injection
needles called EpiPens®. A person having a severe allergic reaction needs an EpiPen injection, as well as immediate medical attention.
Watch More
Do You Have Any Allergies?
How does the body react when it has allergies? Watch this video to learn more about the body’s allergic response.
Why are peanuts a potentially deadly allergy for some people? Watch this video to learn more about peanut allergies.
What happens when the body has a severe allergic reaction? Watch this video to learn more about anaphylactic shock.
Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.
Unit B Lesson 3 Self-Check
Instructions
Complete the following 6 steps.
Don't skip steps – if you do them in order, you will confirm your
understanding of this lesson and create a study bank for the future.
ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.
COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.
REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct
any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.
SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.
CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum,
or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!
Be a Self-Check
Superhero!
Self-Check Quiz Answers
Click each of the suggested answers below, and carefully compare your answers to the suggested answers.
If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.
The toxic particles in cigarette smoke are an allergen that the immune system is reacting to, and trying to remove from the body. A runny nose, watery eyes, and sneezing is a response caused by the immune system to remove smoke particles from
the body.
Many people who need organ transplants die, because not enough people are signing up to donate their organs. The health system could find ways to get more people to sign up to donate their organs when they die.
The immune system is made of special cells that work together to protect the entire body from harmful bacteria and viruses that kill living cells in all the other organ systems.
Reading and Materials for This Lesson
