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I may be very off on many scientific details here, but I'm always all ears.
As far as I understand, any food that is eaten goes to the stomach, gets broken down even further into smaller food molecules, and after a period goes through the intestines where nutrients are absorbed out of this… stomach-output.
Let's say I eat food A sometime, and it's gone down and is now sitting in my stomach, waiting for the stomach to start breaking it down. After a while, I eat food B.
When digestion occurs, is it possible that the stomach only starts breaking down food A's material first before it gets to food B? Is it possible that food B's output goes into the duodenum before food A's output?
Please help break any of this down if it's obvious I've been living in a cave. Thanks!
In general, food is not kept in any particular sequential order. The stomach has a lot of smooth muscle which churns the food, very rapidly erasing any "order" to the food. Beyond that, the stomach digests "the food in the stomach," in parallel. Whatever is in it, it digests.
Now, in general, food eaten earlier will digest into chyme (the digested slurry which enters the intestines) sooner, but that's a very general pattern and doesn't account for any differences in how long it takes to digest various types of foods.
I don't have any sources to back this next claim up, but I do believe that if you were to chew some steak poorly, and then follow it up by more steak chewed properly, the later steak would actually digest first because it would take less mechanical processing in the stomach to get the digestive enzymes to where they need to be to work.
What does the COVID vaccine actually do inside your body? A scientific explanation
Several national polls have shown that as many as 40 percent of Americans are unsure about getting vaccinated.
Just last week in South Jersey, Deborah Heart and Lung Center CEO Joseph Chirichella said that 500 of the Pemberton hospital's 1,100 employees, or about 45 percent, had not yet taken a dose of the COVID vaccine, despite having the option available at their workplace on a daily basis.
People are looking for clarity on what the vaccine does inside the body, and so a scientific explanation can help, according to Ed Dix, a director of pharmacy services in the Inspira Health Network.
Dix and his colleague, Evelyn Balogun, a medical director for Inspira Urgent Care, were generous enough to provide that explanation in layman's terms.
It's Not Just Body Weight, It's Body Fat, Too
A similar thing happens in your brain when it comes to how much body fat you’re carrying. “Your brain measures the level of body fat using leptin, a hormone that’s secreted in your bloodstream in proportion to the amount of fat you carry,” says Guyenet. Higher levels of leptin in your bloodstream mean more fat on your body. You may have heard of leptin before, called one of the “hunger” hormones, along with ghrelin. In terms of leptin, it decreases your hunger.
Whenever your weight changes too much, your brain will intervene to push it back to what it thinks is the correct weight for you.
But here’s where things get tricky. Everyone has a certain level of body fat that their bodies are happiest at. “Your brain will defend this amount just like it defends your body temperature,” explains Guyenet. As you lose weight, the amount of leptin in your bloodstream drops — and that’s where the trouble starts. It sends a signal to your brain to help you fight to bring that fat back. Of course, that’s the exact opposite effect that you’re going for. But it’s hard to beat out biology.
Guyenet calls this a classic starvation response. Your brain responds by upping hunger, making those doughnuts in the break room that’ve been sitting out for four hours look actually yummy, and ensures cravings are impossible to ignore. Physiologically, your metabolic rate slows so you can conserve energy and send it right back into building up fat stores, he says. As a 2011 study in the New England Journal of Medicine shows, these “compensatory mechanisms” driving weight regain last for at least one year, a long time to spend battling your body.
One of the most effective ways to tell if you’re suffering from chronic dehydration is to take a look at your skin. If it’s flaky, cracked, dull and dry all the time, you most likely need to start drinking more water.
AssociatesMD Medical Group notes that dry skin and dehydrated skin are not the same thing. If you skin is just dry normally, then there’s nothing to really worry about. But if your skin appears to be abnormally dry, then your skin cells — and other organs — aren’t getting enough water and it’s time to drink up!
What’s Happening Inside Your Body When You Have Norovirus?
Norovirus, more commonly known as the winter sickness bug, due to the high number of reported complaints around winter time, is a highly contagious stomach bug. Symptoms of Norovirus typically include vomiting and diarrhea and in some cases flu like symptoms, such as headaches, stomach cramps, fever and muscle pain. Norovirus is one of many strains of a single virus called the Norwalk virus, hence the name. Norovirus can share it’s symptoms with non viral infections, like bacterial gastroenteritis, which is not contagious. If you suffer any of the symptoms above, it is always best to assume you have a contagious virus and act accordingly, until advised otherwise by a doctor.
How is Norovirus passed on?
Norovirus is the cause of viral gastroenteritis and affects humans of all ages, passed on by contaminated food, liquid, surfaces, objects or person to person contact. Norovirus is ingested, via the mouth, nose and in rare cases rubbing your eyes after coming in to contact with a contaminated source. While the effects of Norovirus are distressing and exhausting, it is not life threatening to a person with a healthy immune system. It is possible that a person could catch Norovirus and have no symptoms at all, while still being contagious.
What happens next?
After ingestion, Norovirus travels through your stomach to your small intestine. Here Norovirus begins to multiply by attaching itself to the healthy cells within your intestine, taking them over in order to produce more infected cells. A virus cannot multiply on its own, it needs living cells to feed from. Eventually the cells will explode and produce replica cells of the virus. Norovirus will then continue on to more healthy cells and repeat this process.
During this time you will begin to feel unwell, as your body’s immune system realizes something is wrong and starts to produce antibodies to fight the infected cells. Projectile vomiting and diarrhea may occur suddenly. These reactions are your body’s natural response to a virus, as your immune system strives to rid your body of infection by flushing out your system, as Norovirus is affecting your small intestine, not your stomach, this is a pointless side effect.
How long does Norovirus last?
Norovirus usually lasts for one to two days. You will continue to feel unwell and weak as your immune system uses energy to fight off the infection. Gradually your immune system will begin to take over the infected cells and deactivate them, you will begin to feel better but still highly contagious for another 12-48 hours. It is best to stay away from others during this time. Once you have fought off a particular strain of Norovirus, you cannot catch that form of the infection again, although there are many others.
Other effects on the body
Although Norovirus itself is not life threatening, a common side effect of Norovirus is dehydration. It is important to replace any lost fluids during the time of infection to prevent dehydration becoming worse, which can prove to be fatal in extreme cases. Symptoms of dehydration include dizziness, tiredness, dry mouth, and passing dark coloured urine.
Norovirus is very unpleasant but most people make a full recovery in just a few days with no lasting side effects.
All living things need food to survive. It gives us energy for everything that we do. It also gives the body what it needs to repair muscles, organs and skin. Food helps us fight off dangerous diseases.
It is important to eat a wide range of food in order to stay healthy. Nutrition is the science that deals with food and how the body uses it.
How the body uses food
Food has nutrients in it&mdash substances that give our body many important things that we need. They provide us with energy and also help control the way our body grows.
Before nutrients can go to work food must be broken down so that they can pass into our body. This is called digestion. It starts when we chew the food that we eat. When we swallow it it travels on to the stomach where it is mixed together with water and other fluids. Then the food is passed on to the intestine. Nutrients escape through the walls of the intestine into our blood. From there they are carried to all parts of the body.
Most food leaves waste that the body cannot use. Some of it goes to the kidneys and turns into urine. The liver also filters out waste. What is left over passes through the large intestine and leaves our body.
There are six main groups of nutrients: proteins, carbohydrates, fats, vitamins, minerals and water. The energy that food gives us is measured in kilocalories, or one thousand calories. A calorie is the energy that is needed to raise the temperature of water by one degree Celsius.
Although water does not give us energy it is the most important nutrient. We may be able to live on without the others for weeks, but we cannot go on without water for more than a few days.
Water has many functions in our body. It helps break down food. It also cools the body down when it becomes too hot. The body carries away waste products in a watery solution.
Our body needs about 2 &ndash3 litres of water a day. We get it from the water and liquids we drink but also from fruits, vegetables and other food.
Carbohydrates are the main source of energy for our body. Sugars and starches have carbohydrates in them.
Sugar is a simple carbohydrate. It gives us energy very quickly. This form of energy can be found in dairy products, honey, syrup, jams and jelly.
Starches must be broken down into sugars before our body can use them. They are found in beans, bread , potatoes, cereals, corn, pasta, peas and potatoes. They provide our body with a constant supply of energy.
Our body needs fat in small amounts. Fats are made up of carbon, oxygen and hydrogen. They store vitamins and produce fatty acids. We need these acids to produce cell membranes.
Fats can come from animals or plants. They are in meat and dairy products, like butter and cheese. Other types of fats are in vegetable oils, nuts or seeds.
Too many saturated fats produce a high level of cholesterol, a waxy material made by the body. It starts building up in the walls of blood vessels and may block blood as it flows through our body.
Proteins are among the most important building blocks of our body. Muscles, skin and hair , for example, are made up of proteins.
Proteins are complex molecules made up of amino acids. The body can produce some of them itself, but we must get the others from food. Proteins are in cheese, eggs, fish, meat, milk, as well as in nuts, peas and beans.
Minerals are needed for growth. They are inorganic, not made up of living things. Our body needs different amounts of various minerals. Calcium and magnesium, for example, are important for bones and teeth. We also need small amounts of iron. It is a component of haemoglobin, which carries oxygen to red blood cells. Fluorine or zinc are other minerals we need in very small amounts. They are called trace elements.
Our body needs a variety of vitamins to stay healthy. Each of them does a different job. Vitamin A, for example, helps skin and hair grow. Vitamin C is needed to fight off infections. Vitamin D helps the growth of bones and teeth
The right diet
The key to staying healthy is eating the right food. Nutritionists suggest eating according to the food guide pyramid. It has five sections. You should eat a lot of the bottom parts, but only a little of the upper parts.
The Food Pyramid
- Be careful of your weight. Obesity can lead to health problems.
- Exercise every day. It helps the body burn calories and the fat you don&rsquot need.
- Eat a lot of grain products
- Be careful not to eat food that has too much saturated fat and cholesterol
- Do not eat too much sugar. High-sugar foods and drinks have a lot of calories but not many nutrients.
- Don&rsquot put too much salt on your food. This may lead to high blood pressure.
- Include fiber in your diet. It helps food move along in your body.
- Beware of alcoholic drinks. They have a lot of calories but no nutrients.
- Store and cook foods properly so that they do not lose their nutritional value.
Nutrition and diseases
All over the world people suffer from illnesses that are caused by eating the wrong food or not having enough to eat.
In developing countries deficiency diseases arisewhen people do not get the right nutrients. Kwashiorkor is a disease that occurs if your body doesn&rsquot get enough proteins. Marasmus occurs in young children who don&rsquot get enough calories every day. They become weak, underweight and often die.
Diseases often occur if you suffer from a lack of vitamins. Not enough vitamin D, for example, may lead to bone illnesses.
In industrialized countries people often suffer from eating too much. Too much fat and cholesterol in your body can lead to heart diseases, obesity and cancer. High cholesterol levels may make your arteries narrow . The result may be high blood pressure , a heart attack or a stroke.
The lack of certain minerals may also lead to illnesses. Not enough iron in your food reduces the blood&rsquos ability to make red blood cells, which are needed to transport oxygen through our body.
What Happens When You Eat Gold?
The over-the-top garnish is topping more and more dishes. But does it digest?
Instagram has recently turned gold sushi and doughnuts into extravagant, viral sensations, but humankind had long had an appetite for the glittery, malleable metal. While you’re being dazzled by sparkling gold flakes suspended in your cocktail, or the delicately laid leaf surrounding your bonbon, one thought may cross your mind: n I really eat gold?” Or, if you’re like me, the question is just “why eat gold?” Afterall, it&aposs basically flavorless.
Regardless, for centuries, thinly pounded sheets of pure gold have been used as garnish in European pastries and ground into Japanese green tea. As far as we know, nobody has died from gold poisoning (except the lady in that James Bond movie and that Targaryen dude in Game of Thrones… oh, spoiler alerts). I asked a couple of nutrition experts, New York-based registered dietitians Alexandra Oppenheimer and Cynthia Sass, to weigh in on the prospect of gold being harmful to your biology.
Oppenheimer points out that when you do eat gold, you’re not just eating your wedding ring. ible gold must be 23-24 carats,” she tells me. “It’s not the same gold you find in your jewelry, which may have other metals and can be toxic and dangerous if consumed.” The gold used for edible applications is known, at least in Europe, as E-175, a designation given by the European Food Safety Administration (EFSA) when using the metal as an additive or food coloring. The effects and safety of E-175 were first evaluated back in 1975 and recently re-evaluated in 2016 by EFSA.
According to that most recent opinion, gold leaf must be 90 percent pure gold, with the other 10 percent typically consisting of another safe metal, like pure silver. Assuming your gold checks out (and, to be fair, from all available information the gold leaf currently sold as ible” does pass the test) it’s not going to do anything to you. Scientifically speaking, gold is chemically inert, meaning it won’t break down during digestion. “Most likely edible gold won’t be absorbed from the digestive system into the bloodstream, and therefore it will pass through the body and eliminated as waste,” Sass explains. 𠇋ut this may depend on the size, amount, and frequency consumed.”
And that’s where the research on gold as a food additive hits a slight roadblock — that roadblock being the near non-existence of any research.
The EFSA cites a “lack of data on toxicity, purity and the exact nature of gold used on or in foods.” So, to fill in the gaps they, appropriately, looked at gold dental fillings for insight. As gold has been commonly used for decades in dentistry, we do know that the effects of it on the body are, at the worst, a rash for those hypersensitive to the metal. Gold particles do appear in the saliva samples of people with gold fillings, so it𠆝 be safe to assume those people are swallowing them and that it is not causing any harm.
Another application of ingested gold is in medications, which have been used homeopathically throughout history, but also pharmaceutically, as it is in the treatment of rheumatism. In the latter case, gold is used in conjunction with sulphur and phosphor as a sort of a delivery system for the actual medication and some studies suggest the precious metal has anti-inflammatory capabilities. The only danger gold could produce is on the nanoparticle level where it can be destructive to cells when injected directly into them in lab experiments. However since gold nanoparticles are too big to permeate a cell membrane, that threat is nearly non-existent. The EFSA findings do indicate that liquors like Goldschlager could have suspended gold nanoparticles in them, but again, they don’t seem to be able to do much to you.
Video: Vanilla Bean Kulfi at Paowalla
At this point, you may have noticed everything referenced above about the safety of gold as a food additive is from a European inquiry. In fact, the U.S. Food & Drug Administration (FDA) doesn’t have guidelines for gold consumption, specifically due to a lack of inquiries about it (though they do tell you to make sure you’re not eating inedible metals on your cupcakes). The closest the United States can come to an official stance is from the Centers for Disease Control, which does not designate gold as a poison. So there you go: gold is not poison.
Still, it’s probably best to not make gold part of your daily diet. “I recommend exercising caution when selecting your dining bling,” Oppenheimer warns. “Since it’s not well studied, let it only adorn on seldom special occasions.” Sass agrees, saying a gold adorned meal should be a “once in a lifetime” event.
In short, we really don’t know too much about what happens when we eat gold, other than it makes our poop extra fancy. And even then, Oppenheimer says don’t get your hopes up. “It’s highly unlikely that you’ll see it come out the other end as it will likely be hidden in the rest of your fine dining experience.” The good news? It probably won’t harm you. The bad news? Until more studies are conducted, we’ll have to keep saying “probably.”
What determines whether a food is acid-forming or alkaline-forming inside our body?
Digestion begins with our saliva, the moment food enters our mouth. Once food makes its way through our digestive tract, the enzymes and acids in our stomach further break it down and the effect is not dissimilar to &ldquoburning&rdquo it. The punchline is that the food&rsquos pH can change once it&rsquos been &lsquoburned&rsquo. So again, something that is acidic in nature (like lemons) can produce an alkalizing effect on our blood upon digestion.
This is how scientists determine a food&rsquos pH effect on the body: They incinerate the food, mix the ash with water, and then analyze the mineral content of the ash. If the mineral content is highly alkaline, then the food will likely have an alkalizing effect on the body (even if it was acidic outside of the body), and vice versa. Pretty cool, right?
When will my baby get a bath?
Babies have traditionally been given their newborn bath not long after birth. But research is showing there are advantages to waiting at least 12 hours. A delayed bath:
- Promotes breastfeeding. The amniotic fluid that remains on your newborn may provide breastfeeding cues for her. Researchers theorize this may be one reason why delayed bathing in hospitals resulted in increased breastfeeding rates. A study of almost 500 babies published in the Journal of Obstetric, Gynecologic & Neonatal Nursing found that delaying a healthy newborn bath for more than 12 hours after birth resulted in a greater rate of exclusive breastfeeding in the hospital and increased rates of mothers planning to breastfeed (either exclusively or in combination with formula) after leaving the hospital.
- Keeps your baby warm and reduces stress. Longer skin-to-skin contact with you reduces her stress level and keeps her warm. To keep a newborn warm, the World Health Organization (WHO) recommends delaying a baby's first bath for at least six hours and ideally 24 hours after birth. (Because babies have a hard time regulating their temperatures, baths can easily chill and physically stress them.)
- Protects your baby's skin. The waxy, whitish vernix that coats your baby protects and moisturizes her skin. It also helps keep her warm. There's no need to rush to wash it off.
- Cultivates good bacteria. Delayed bathing may help a baby develop her microbiome – her normal bacterial flora, which researchers think may play a part in disease prevention.
Ask what the hospital's usual procedure is for bathing newborns, and request a delay if you prefer that. Baths usually take place in the nursery, where the baby is put under radiant heat for warmth. Parents can usually watch and even participate. Some parents find that the hands-on experience gives them more confidence bathing their baby once they get home, especially if she's their firstborn.
Everything You Need to Know About the Female Orgasm
If you took sex-ed at school, you probably learned all about pregnancy, STIs, and safe sex practices. While all of that is super important, there's a pretty good chance that your teacher never once uttered the word "orgasm" throughout the semester. Which, is pretty weird, considering it's a natural biological function, and sexual pleasure is a normal, healthy part of life.
Let's actually talk about orgasms for a sec. An orgasm is what happens when a person reaches the height of sexual excitement, which comes with feelings of pleasure and muscle contractions in the genitals. For men, this moment also means ejaculating &mdash but let&rsquos talk about the other, awesome kind of orgasm: the vaginal kind.
Since sex-ed teachers aren't discussing it, I talked to Dr. Melisa Holmes, adolescent gynecologist and cofounder of Girlology to answer your most pressing questions about the biological reaction so you can feel more comfortable with your body and the sexual pleasure you deserve.
What is an orgasm?
An orgasm is a physical reflex, brought on through sexual stimulation, most commonly that of the clitoris, which is the most sensitive organ in the vagina. "It's a build up to a time frame during sexual stimulation where there's just this big release of pleasure," says Dr. Holmes. During sexual arousal, blood flow increases to the genitals and your muscles tense throughout your body. The orgasm then "reverses this process through a series of rhythmic contractions," according to Brown University. During an orgasm, "endorphins are released into the bloodstream and these chemicals might make you feel happy, giddy, flushed, warm or sleepy."
How do I orgasm?
Different people are stimulated by different sexual acts, but it really all comes back to the clitoris. Some people may also require the additional sensation of vaginal penetration to orgasm. In general, when you're reaching climax, the clitoris will get engorged and lubricated. "The clitoris may just look like a little bump on the outside, but it actually has a lot more to it on the inside and just the stimulation of that creates this intense kind of burst of pleasurable feelings," says Dr. Holmes.
There are other erogenous zones that feel good when kissed and touched, but they probably won't stimulate an orgasm. "A true orgasm really does require genital stimulation and most medical providers will tell you it stems from the clitoris," Dr. Holmes says.
There's nothing wrong with experimenting and figuring out what allows you to reach sexual climax. It could be oral stimulation of the clitoris, rubbing on the inner thigh, or a mix of multiple things. "The best way to learn, if you're curious, is to teach yourself, give yourself an orgasm," Dr. Holmes says. "Don't rely on other people. I think that's really important to understand that they can make themselves have an orgasm probably better than anyone else can. And they don't need a partner to do that."
What does it feel like?
An orgasm feels different for everyone, but there are some common experiences like heavy breathing, body vibrations, and sweating. Orgasms can be mild or overwhelming, they range from person to person and time to time. We asked some real girls what orgasms feel like and this is what they said:
"It's like the burst you feel when you get a text from your crush. but in your vagina." &mdash Cam, 15
"I would compare orgasms to going out to eat. You wait and wait for your food, very excited for this meal, then the meal gets there and you take your first bite and you're flooded with happiness. Take a food orgasm and times it by 10!" &mdash Evie, 17
"My clit pulses &mdash a lot. It gets super, super sensitive. Also, I can feel my vaginal walls involuntarily clench, too." &mdash Annie, 20
"Having orgasms makes me feel connected to my own body. It was revolutionary to me the first time I had one. I've had this body my whole life and was missing out on something so big." &mdash Alexis, 17
"Uncontrollable, amazing tingling sensation all over the body." &mdash Kendra, 18
"Like I have no control over my body whatsoever with a ticklish sensation. in the most sexy way possible." &mdash Taylor, 22
As you can see, it feels a little different for everyone, but the common denominator is it feels good.
Why didn't I orgasm?
According to Brown University, one in three people have trouble orgasming from sex with their partner. Since some need clitoral stimulation to climax, simple penetrative sex might not get you there.
When you first start exploring your sexuality, it can take a little bit of time to discover what makes you climax.
Masturbation is the easiest way to explore what will allow you to reach sexual stimulation. Different rhythms, sensations, and pleasures affect people differently. If you're exploring with a partner, there's nothing wrong with asking them to focus on a specific area or action.
There are also external factors, like stress, that may affect your ability to orgasm. "A lot of an orgasm also stems from our brain," Dr. Holmes says. "We have to feel comfortable and safe to have good sexual function." Using drugs and alcohol can also affect one&rsquos ability to climax.
"Everyone thinks alcohol makes sex better," Dr. Holmes says. "And a tiny little bit of alcohol might enhance your sexual experience because it decreases your inhibitions, but too much alcohol can absolutely prevent orgasm. If you're drunk, you may not even notice the stimulation as much, you're a little more numb." Prescription drugs can have a similar affect. "Especially the SSRIs that are used for depression and anxiety. Those are the most common drugs that prevent or inhibit orgasm," Dr. Holmes says.
Do I have to orgasm during sex?
This is a complicated question because, no, technically you don't have to orgasm during sex. Vaginal penetration or stimulation can still feel good without reaching sexual climax. And biologically-speaking, even if you're trying to have a baby, a vaginal orgasm isn't necessary (of course, the penis must ejaculate because sperm is needed to fertilize the egg). That being said, there may be a biological reason why we have vaginal orgasms: so that we want to have sex again. "It makes sense that sex feels good so that you are willing to have sex," Dr. Holmes says. "So the species can be perpetuated."
So, if you're not orgasming every time with your partner, it's NBD. That being said, if you want to orgasm and you feel like your partner isn't spending the time on you to reach climax, have a conversation about it. If they care about you, they'll put in the extra work to make you feel good.
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Systems of the Human Body
To understand that there are different systems within the body and that they work independently and together to form a functioning human body.
At this level, children can begin to view the body as a system, in which parts do things for other parts and for the organism as a whole. Through the use of an online interactive activity, children learn about the concept of separate components working together to build a body system. In addition, this lesson focuses on activities to help students learn that body systems work together to build the functioning human body. This lesson could be used in conjunction with instruction on the human body and/or systems.
In order to be able to do this lesson, students should understand that most items are composed of different parts and that an item may not work if its parts are missing. Also, they should know that an assembly of parts can perform functions that the single parts cannot perform alone. More specific to the human body, students at this level should realize that the human body has parts that help it seek and take in food when it feels hunger. They should understand that the brain is the part of the body that enables humans to think and it communicates with the other parts of the body.
This prerequisite knowledge should help elementary-school students understand that parts within a system usually influence one another and that a system may not work as well, or at all, if a part is missing, broken or worn out, or misconnected. In addition, they should be able to make correlations about systems in general to systems of the human body. Specific to the human body, students should understand the following: by eating food, humans obtain energy and materials for body repair and growth by breathing, humans take in the oxygen they need to live by communicating with all parts of the body, the brain understands what is going on at different parts throughout the body and the skeleton provides the body with structure and protection.
Research indicates that elementary students may believe that a system of objects must be doing something (interacting) in order to be a system and/or that a system that loses a part of itself is still the same system. (Benchmarks for Science Literacy, p. 355.) Research shows that student misconceptions about systems arise from their difficulty in recognizing that a natural phenomenon (e.g., the human body) occurs by systems working independently and together (e.g., circulatory, respiratory, nervous, digestive). Studies of student thinking show that, at all ages, they tend to interpret phenomena by noting the qualities of separate objects rather than by seeing the interactions between the parts of a system.
For upper elementary-school students, research specific to the human body indicates that, in terms of internal bodily organs, upper elementary students are able to list a large number of organs. In terms of the nervous system, they know the brain helps the body parts but do not always realize the converse (that the body helps the brain). They do know, however, that nerves conduct messages, control activity, and stabilize the body. Upper elementary students do not understand the brain's role in controlling involuntary behavior. In terms of the digestive system, once students reach the fifth grade, they know that food undergoes a transformation process in the body. In terms of the respiratory system, they associate the lungs' activities with breathing. Further, they may have some knowledge about the exchange of gases in the lungs and understand that air goes to all parts of the body. In terms of the circulatory system, upper elementary-school students realize that the heart is a pump, but they do not realize that the blood returns to the heart. (Benchmarks for Science Literacy, pp. 344-345.)
Questions about familiar body systems can be useful in getting students to start thinking about systems in general. This process can initiate the understanding that each organ affects and is affected by others.
Hold up an apple (or some other healthy snack). Ask students:
- What am I holding in my hand?
- If I were going to eat this apple, what parts of my body would I use?
Have students discuss the body parts we use when biting, chewing, swallowing, and digesting an apple. You may want to create a chart on the blackboard or a large sheet of paper to record students' ideas. If so, you can use these categories to help you organize the information:
- Body Parts for Biting
- Body Parts for Chewing
- Body Parts for Swallowing
- Body Parts for Digesting
- How do the different parts work together? (Each part plays a special role, so once one task is accomplished, then the next part can perform it's role.)
- What happens if one of the parts is missing? (For example, if the teeth were missing, then it would be difficult if not impossible to chew some foods, and if one couldn't chew something large to get it small enough to pass through the esophagus, then they could choke.)
Continue to guide student understanding of systems by asking:
- Who remembers what it's called when a number of different parts work together to make something happen or function? (Guide students so that they come up with system as an answer.)
- Can you think of an example of a system? (Some possible examples are a bicycle, a computer, a school, or a bus.)
- For the system you picked, write down any parts that belong to that system. (For example, some parts that are necessary for a bicycle are two wheels, gears, brakes, foot pedals, and handles.)
Now have students use the All Systems Go! student esheet to access the All Systems Go! interactive. This activity requires students to drag organs of different body systems into the human body cartoon (Arnold) classifying them according to certain systems (digestive, skeletal, circulatory/respiratory, and nervous). For each system, once the correct organ is placed into the body, it will stay there. However, if an incorrect organ is placed into the body, all the organs will move out of the human body (Arnold) and the student will have to start over for that body system. Once all of the correct organs for a body system have been placed within Arnold, the next organ system will automatically appear at the bottom of the screen. When all four systems are done, the clothed Arnold will reappear.
The student esheet includes both instructions on how to play the interactive activity and questions regarding the activity. Answers to the questions can be found in the activity and in the Learn More section on this site. To answer the questions students can use the All Systems Go! student sheet.
- What body system helps humans turn the food they eat into energy? (Digestive.)
- What body system helps humans breathe? (Respiratory.)
- What body system controls other body systems? (Nervous.)
- What body system provides structure for the body? (Skeletal.)
- What body system allows us to move? (Muscular.)
- What body system includes a transport system (blood) and a pump (the heart) that keeps the transport system moving? (Circulatory.)
- Can you think of two body systems that work together? (Examples include the respiratory and circulatory, muscular and skeletal, digestive and circulatory, and nervous and any other system.)
- What part of the nervous system is essential for it to work properly? (Brain.)
- What event could disrupt one or more body systems? (Injury or disease could disrupt one or more body systems.)
- What parts of the respiratory system would need to be blocked to not allow any air into this system? (The mouth, nose, or trachea.)
This activity should help teach students that organs within a system work together to make that system function, and it should be pointed out that in turn all systems function together to make the human body function.
At this point, ask students to name any other body systems. See how many systems they can generate on their own and fill in the gaps where necessary. The primary focus of this lesson is the digestive, respiratory/circulatory, skeletal, muscular, and nervous systems.
|Body systems covered:||Other body systems:|
|Nervous (includes the 5 senses)|
Note: Students should focus on the fact that systems work together not necessarily on the names of each organ.
The main point of this lesson is to understand that there are different systems within the human body and that these systems work independently and together to form a functioning human body.
Ask students to revisit the questions from the Motivation that they answered before they did the online interactive activity (see the first two questions below). They should answer them again with their new knowledge and then answer the third question. Give students five to ten minutes to do this and then have them share what they wrote down before and after doing the online interactive.
- Who remembers what it's called when a group of things function together as a whole?
- Can you think of an example of a system? For that system, name some of its parts.
- What six body systems did you learn about in this lesson?
Next, ask students to hypothesize about what might happen if part of a body system were missing. Once they've come up with their theories, have students create a poster of a body system working properly and one that is not because it is missing one or more of its parts. When they are done with their posters, have students share them with the rest of the class. Students can view each others posters and discuss the different systems.
Innerbody provides in-depth coverage of ten body systems. It includes clickable body diagrams with many components of each body system.