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Most living things try to protect themselves from harm. Animals have a special protection called the immune system. The immune system protects the body from substances called...

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How Does the Immune System Work? (Video)

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The Immune System Video  | How to boost your Immunity  | What is immune system and its function?

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Digestive System Movie - learn about how the digestive system works 

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Digestive System Movie - learn about how the digestive system works 

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How Does the Digestive System Work? (Video)

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Watch this movie about your digestive system, the system that handles the food you eat.

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How your digestive system works - Emma Bryce

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The human digestive system - National Geographic Kids

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Facts Just for Parents, Teachers and Students

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Name: Respiratory

System: The respiratory system

Location: Upper body, throat and head

Purpose: Breathe in oxygen and breathe out carbon dioxide

Organs: Nose, mouth, trachea, lungs and diaphragm

TA ID: A06.0.00.000

FMA ID: 7158

27 Respiratory System Facts for Kids

1. The respiratory system is a group of organs in the human body that exchange oxygen and carbon dioxide.

2. The respiratory system is what allows humans to breathe in oxygen and exhale carbon dioxide.

3. The respiratory system consists of quite a few organs, including the lungs and the diaphragm.

4. The maximum capacity of adult human lungs is about 1.5 gallons.

5. The human body takes around 17,000 breaths each day or around 2,000 gallons of air.

6. The lungs are where the gas exchange happens, oxygen is brought into the body and carbon dioxide is released.

7. The diaphragm is the muscle that controls around 80% of the breathing a human does.

8. There are two parts to the respiratory system, the upper respiratory tract and the lower respiratory tract.

9. The upper respiratory tract is the nasal cavity, paranasal sinuses, part of the throat (pharynx) and the larynx (voice box).

10. The lower respiratory tract is the trachea, bronchi, right lung, left lung and the diaphragm.

11. The respiratory system is the attack vector (entry point) for many viruses, bacteria and fungus.

12. When you have a respiratory infection, it is classified as an upper respiratory infection or a lower respiratory infection.

13. An upper respiratory infection is an infection in the upper respiratory tract.

14. A lower respiratory infection is an infection in lower respiratory tract.

15. Asthma is a disease that is caused by long-term inflammation of the bronchial tubes.

16. Doctors don't know why some people get asthma and others don't. The theory is asthma is caused by air pollutants, allergens or genetics.

17. In 2015, it's estimated that 358 million people worldwide had asthma and it caused over 397,000 deaths.

18. Chronic obstructive pulmonary disease, also known as COPD, is a respiratory disease where damage to the lung tissue and alveoli (air sacs) makes it hard to breathe.

19. COPD is caused by smoking and breathing in harmful chemicals.

20. In 2015, it's estimated that over 174 million people had COPD and it caused 3.2 million deaths.

21. Pneumonia is a potentially deadly infection of one or both lungs.

22. Pneumonia causes fluid buildup in the lungs and prevents your body from getting enough oxygen.

23. Pneumonia can be caused by a virus or bacteria.

24. In the United States, around 250,000 people are hospital due to pneumonia and around 50,000 die.

25. Lung cancer is a form of cancer that originates in your lungs.

26. Lung cancer can be caused by smoking, environmental pollutants and genetics.

27. In 2018, lung cancer was responsible for the deaths of over 1.7 million people worldwide.

Pictures of the Respiratory System

A diagram of the entire human respiratory system. Credit: Bruce Blaus

A diagram showing how humans breathe in and out. Credit: Encyclopædia Britannica, Inc.

An MRI image of the human respiratory system. Credit: The European Respiratory Society

Additional Resources on the Human Respiratory System

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Respiratory System Facts for Kids - Facts Just for Parents, Teachers and Students

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Name: Respiratory System: The respiratory system Location: Upper body, throat and head Purpose: Breathe in oxygen and breathe out carbon dioxide Organs: Nose, mouth, trachea, lungs and diaphragm TA ID: A06.0.00.000 FMA ID: 7158 The respiratory system is a group of organs in the human body that exchange oxygen and carbon dioxide.

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Respiratory System | The Dr. Binocs Show | Learn Videos For Kids

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Have you ever accidentally touched a hot surface? Did you immediately yank your hand away? That's your nervous system at work.

The nerves in your hand sent a message to your brain: "Hey, this is hot! Ouch!"

Your brain processed this information and sent a message back to your hand: "Danger! Move your hand away!"

If it seems like this all happens very quickly, that's because it does! Your body can send messages to your brain at the speed of 200 miles per hour (mph).

What is the Nervous System?

Let's start learning some nervous system facts. You're going to learn all about neurons, the spinal cord, and more!

Nervous System Definition

The nervous system is your body's communication center. It is made up of the brain, the spinal cord, and a network of nerve cells (neurons) that runs through your entire body.

Your brain and other parts of your body communicate through the nervous system. This system allows your body to send observations and information to the brain.

The brain then processes this information and tells the rest of your body what to do.

Your brain also controls things you probably don't think about, like your breathing and the beating of your heart.

Major Organs of the Nervous System

The nervous system consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body.

How does the Nervous System Work?

The brain is basically the super computer of the nervous system. It's the boss that receives messages and sends orders.

The spinal cord is another important part of the nervous system. It runs from your brain down through your back.

It also contains nerves that branch out to every organ and body part.

Tiny nerve cells called neurons send messages along the spinal cord to the brain and other body parts. There are neurons throughout your entire body, and there are 100 billion neurons in your brain.

Different neurons have different jobs. Sensory neurons take information from the eyes, ears, nose, tongue, and skin to the brain.

This information is about what you see, hear, smell, taste, and touch. Motor neurons carry messages away from the brain and back to the rest of your body.

Information is sent from neuron to neuron as it travels to or from the brain. When you learn new things, the brain creates pathways between the neurons so that new skills become easier over time.

Parts of the Nervous System

The nervous system is divided into the central nervous system and the peripheral nervous system.

Central nervous system (CNS)

This is the part of the nervous system that includes the brain and spinal cord.

Peripheral nervous system (PNS)

This refers to the nerves outside of the brain and spinal cord. The PNS connects the CNS to the organs and other body parts so messages can travel from the body to the brain.

The peripheral nervous system is then divided into the somatic nervous system and the autonomic nervous system.

Autonomic nervous system

This is responsible for the processes we don't have to think about, like breathing and digestion.

Somatic nervous system

This is responsible for muscle movements that we can control and for reflexes.

Fun Facts About the Nervous System

There are more nerve cells in the brain than stars in the Milky Way.

Nerves are covered by a substance called myelin that helps messages move quickly through the body.

The spinal cord is just 19 inches long, but it holds over 10 million neurons.

You can help your nervous system stay fast and healthy by exercising and eating a balanced diet!

More human body facts.

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Must-Read Nervous System Facts For Kids in [year]

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Nervous System Facts Have you ever accidentally touched a hot surface? Did you immediately yank your hand away? That's your nervous system at work. The nerves in your hand sent a message to your brain:

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Circulatory System Fun Facts: The heart is the central functional unit of the human body, without which all other organ systems fail to function. The pumping action of the fist-sized heart helps transport oxygen dissolved in the blood to every tissue and organ system of the body.

So, it would be appropriate to say that the heart is the only organ that works tirelessly to ensure the proper functioning of the human body. The heart is at the center of the circulatory system, comprising blood, blood vessels, lymph, and lymphatic vessels. Its primary function is transporting oxygen-carrying blood toward the other tissues and organs and bringing deoxygenated blood back from the tissues and organs toward the heart.

This cycle of events keeps the human body functioning. Individually, the cardiovascular or circulatory system also plays a vital role in the development and governance of the Immune system which is responsible for fighting infections and establishing defense mechanisms of the human body.

Top 25 Circulatory System Fun Facts

The following are the top 25 circulatory system fun facts:

The circulatory system has a length equivalent to 100,000 kms.

The circulatory system comprises blood vessels: arteries, veins, and capillaries running throughout the length of the human body.

If laid end to end, the entire circulatory system could run a span of about 60,000 miles.

Most of this length would be comprised of the tiniest blood vessels that link arteries and veins, called the capillaries.

The RBCs move in a single file, one after the other, in capillaries.

The RBCs are small in size, and the diameter of the capillaries is even smaller, measuring about 8 microns.

To move through the capillaries, the RBCs have to squeeze themselves and move in a single file, one after the other.

The RBCs also change shape when moving through capillaries. A calcium-mediated signaling pathway is thought to be causing this distortion in shape.

Higher body mass or size is related to slower heart rate.

Throughout the animal kingdom and mammals, in particular, body size is inversely proportional to the heart rate of the organism.

Young children have a heartbeat higher than that of adults. This changes as they grow over time.

Larger animals also have larger hearts to transport blood to every body part.

The heart can beat outside the body for a short period.

Technically, the heart creates its electrical signals and impulses, which cause it to beat.

Due to this feature, if separated from the body, it continues to beat for a short period.

Usually, a heart can beat for around 3-5 minutes outside the body, until it runs out of energy. However, in a medical facility, it can probably survive up to 4 hours.

Red Blood cells do not contain nuclei.

The red blood cells are primarily oxygen-carrying cells, which impart a red color to the blood due to the presence of heme.

Red blood cells are devoid of any nucleus, and therefore, do not have any genetic material.

The absence of nuclei ensures that the red blood cells can carry oxygen molecules to the best of their ability by providing enough space for the heme-oxygen moiety.

Blood flowing through the body is found in varying shades of red.

Blood flowing towards the cells from the heart is rich in oxygen and is called oxygenated blood. This blood is bright red.

Blood that flows towards the heart, from the tissues, contains carbon dioxide (CO₂) and is called de-oxygenated blood. The deoxygenated blood is darker in color than the oxygenated blood.

This behavior differs from other species, such as mollusks and arthropods, where the color of oxygenated blood is blue.

On an average, the heart beats around 2.5 billion times in a person's lifetime.

The heart is an organ that never tires and beats continuously to supply blood and oxygen to every part of the human body.

The heartbeat of an average human being would be around 70-78 beats per minute. Although, this would differ during rest and exercise.

The resting heart rate can predict heart disease risk in women.

Heartbeat measured at rest is also known as the resting heart rate, and it is typically found to be between 50 and 100 bpm.

However, a lower resting heart rate indicates efficient cardiovascular function and is associated with good heart function.

A resting heart rate higher than 76 beats per minute, especially in women, is associated with an increased likelihood of heart disease.

The heart pumps about 2,000 gallons of blood in a day.

Every minute, the heart pumps around five quarts of blood throughout the body.

On average, blood takes around 20 seconds to circulate through the entire vascular system in the resting state.

In a day, blood travels approximately an equivalent of 12,000 miles throughout the human body.

The human body has two circulatory systems.

The human body has two interconnected circulatory systems: the systemic and the pulmonary.

The systemic circulatory system takes oxygen-carrying blood from the heart toward the tissues and organ systems.

The pulmonary circulatory system carries oxygen from the external environment and enters the blood through the lungs. At the same time, the blood carrying carbon dioxide generated from the tissues is released out into the external environment.

Eight million blood cells die every second in the human body and about the same are born as well.

The red blood cells are formed from hematopoietic stem cells in the bone marrow. They live for about 4 months and are finally destroyed in the spleen.

In a tiny drop of blood, about 5 million blood cells exist.

Each blood cell takes about 20 seconds to travel throughout the body and usually takes about 200,000 trips in its entire lifespan.

Blood travels in both arteries and veins in the body, depending on where it is originating from.

Oxygen-carrying blood traveling from the left side of the heart is carried in arteries towards the tissues and organ systems.

De-oxygenated blood traveling from the tissues towards the right side of the heart that eventually reaches the lungs travels through the Veins.

Capillaries are tiny blood vessels found on the ends of arteries and veins that help the blood to move into or out of the larger blood vessels.

Blood vessels act as a first line of defense for the brain.

A network of blood vessels works together to keep harmful substances out of the brain.

They act as a defense system known as the blood-brain barrier.

The blood-brain barrier allows water and other molecules to pass through, filtering out microbes and pathogens and preventing them from entering the brain.

The weather affects the blood vessels.

Brain freeze is caused by the temperature control function of the blood vessels.

When a cold object such as a popsicle or ice cream touches the roof of the mouth, the blood vessels rapidly constrict, trying to minimize heat loss.

Following this, they relax to restore the blood flow to the roof of the mouth.

The swift response causes a short burst of pain that lingers for a few minutes. They are also called ice-cream headaches or brain freeze and are also commonly found in people with migraines.

The heart is powered by an electric system called the cardiac conduction system.

Laughing helps to keep the heart healthy and reduces the risk of heart disease.

Laughter helps boost the immune system's function and reduce stress by increasing blood circulation.

By triggering the release of a substance known as endorphins into the bloodstream, it helps to relax the body and boost energy levels.

It is beneficial overall for cardiovascular health and helps lower blood pressure.

The sympathetic nervous system innervates the blood vessels.

The Inner musculature of the blood vessels contains nervous receptors such as alpha-1, alpha-2, etc.

The receptors present inside the blood vessels help transmit information regarding oxygen content and blood pressure.

This information is then sent to the brain, which controls the dilation and constriction of the blood vessels.

Blood vessels are made up of only one type of muscle cells.

The inner walls of the blood vessels contain only smooth muscle cells.

The smooth muscles are found along with the connective tissue and the elastic fibers, bundled inside a region known as the tunica media.

The skeletal muscles that aid movement also help move the blood from the periphery toward the heart.

There are two major types of arteries present in the cardiovascular system.

Arteries are blood vessels that carry oxygenated blood from the heart toward the tissues and organs. They function under high pressure and, for this reason, contain high amounts of elastic fibers.

There are two types of arteries present in the circulatory system: Elastic and Muscular.

Muscular arteries contain more smooth muscle in their tunica media, whereas elastic arteries contain more elastic fibers in their tunica media. Elastic arteries are found closer to the heart and help maintain a constant pressure gradient.

The circulatory system, comprising the heart and blood vessels that innervate the human body, is vital for any other organ system to function fully. It provides oxygen and nourishment to tissues and organs, thus keeping them alive and functional.

The functions of the circulatory system overlap with that of the respiratory system, which helps supply oxygen inhaled by the lungs, and give out carbon dioxide gathered as a by-product from tissues and organs, that is finally removed from the body through the process of exhalation.

The pumping action of the heart ensures that blood reaches every other organ system. Damage to blood vessels, cardiac muscle, or the heart's function due to lifestyle or diet can increase the risk of heart disease.

Cite This Page

"Anatomy, Blood Vessels - StatPearls - NCBI Bookshelf". Accessed January 01, 2019. Link.

"20.2 Blood Flow, Blood Pressure, and Resistance - Anatomy and Physiology". Accessed January 01, 2019. Link.

"The squeezing of red blood cells through capillaries with near-minimal diameters | Journal of Fluid Mechanics | Cambridge Core". Accessed January 01, 2019. Link.

"How does heart size relate to the size of an animal? | Socratic". Accessed January 01, 2019. Link.

"Artificial hearts - Heart Foundation". Accessed January 01, 2019. Link.

"Chat Q&A: Why do red blood cells lose their nucleus as they mature? - National Human Genome Research Institute (NHGRI)". Accessed January 01, 2019. Link.

"About the Heart and Blood Vessels". Accessed January 01, 2019. Link.

"High resting heart rate predicts heart risk in women at midlife - Harvard Health". Accessed January 01, 2019. Link.

"Amazing Heart Facts - Arkansas Heart Hospital". Accessed January 01, 2019. Link.

"How does the blood circulatory system work? - Informed Health Online - NCBI Bookshelf". Accessed January 01, 2019. Link.

"Facts About the Cornea and Corneal Disease | National Eye Institute". Accessed January 01, 2019. Link.

"THE LIFE SPAN OF THE HUMAN RED BLOOD CELL". Accessed January 01, 2019. Link.

"The Heart and Blood Vessels - Genes and Disease - NCBI Bookshelf". Accessed January 01, 2019. Link.

"Comprehensive Cancer Information - National Cancer Institute". Accessed January 01, 2019. Link.

"Effect of cold on the blood vessel wall. - PubMed - NCBI". Accessed January 01, 2019. Link.

"Brain Freeze Causes and Treatment | UPMC HealthBeat". Accessed January 01, 2019. Link.

"Antioxidants in cocoa and chocolate milk | American Institute for Cancer Research (AICR)". Accessed January 01, 2019. Link.

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Top 25 Circulatory System Fun Facts (Updated 2023) | BioExplorer

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The heart is the central functional unit of the human body. Explore the top 25 circulatory system fun facts and learn the important functions of the heart.

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The circulatory system in the human body for kids - Smile and Learn

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THE CIRCULATORY SYSTEM | Educational Video for Kids.

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Kids learn about the science of the Nervous System in the human body. Brain, spinal cord, and nerves communicate.

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Animals constantly use their senses to gather information about their surroundings. Nerves in the body pick up this information. In most animals the nerves send the...