The human body
The human body is very advanced. Its brain is more powerful than a computer. Its DNA can stretch to the Sun and back many times. There are many things in the human body that we don't know about. In this post, you will learn about the human body.
Bones
If you didn't have bones, you wouldn't have any shape. The outside of a bone is tough and hard, but the inside is soft and spongy. The spongy bit is called bone marrow. Bone marrow makes white blood cells.
Muscles
If you didn't have muscles, you wouldn't be able to move. There are many muscles in the human body. There are leg muscles, arm muscles, hand muscles, feet muscles, and many more.
Muscles are attached to bones by strings called tendons. The largest muscle is the heart. It pumps blood around the body, and never takes a break.
Cells
Red blood cells
Red blood cells are the cells that make your blood look red. They transport oxygen throughout your body.
White blood cells
White blood cells are the police of your body. When it sees a cell that's bad for your body, the white blood cell eats it.
Platelets
Platelets seal up cuts. Whenever you get a cut, platelets will grab the edges of the cut and stick themselves together until the cut is completely sealed.
DNA
DNA is what gives you personality. DNA looks sort of like a twisty ladder. If all your DNA was put end to end, it would stretch to the Sun and back more than 200 times.
The digestive system
Whenever you eat, the digestive system goes into action. There are several sections in the digestive system: the mouth, the esophagus, the stomach, the small intestine, the large intestine, and the anus. The entire digestive system is roughly the length of a school bus.
The mouth
The mouth is the first step in digestion. Your teeth grind food down, and saliva (spit) helps. Then you swallow it, and it goes to the next step in digestion: the esophagus.
The esophagus
The esophagus is a tube that food goes down to reach the stomach. A tissue in the esophagus prevents the food from going down the windpipe. Muscles in the esophagus force the food down.
The stomach
The stomach is the next step in digestion. It has a strong acid in it that breaks down the food even more. The acid could eat right through a piece of wood. Once the food has been ground into a soup-like mush, it gets flushed out of the stomach and into the next step in digestion: the small intestine.
The small intestine
The small intestine is the next step in digestion. It sucks the nutrients out of the food and transports it around the body. But there is still food remaining. This goes on to the final step in digestion: the large intestine.
The large intestine
The large intestine is the final step in digestion. All the moisture is sucked out of the food. The waste is then pushed out of the body by the anus.
The brain and the nervous system
The brain
The brain is the command center of your body. It controls your movements. It makes decisions. It stores you memories. The brain also gives us dreams. It is located in the top part of your head. The skull protects our brain. The human brain is the most advanced brain on the planet.
The nervous system
The nervous system is a series of nerves that travel around the body. They deliver the brain's messages. Have you ever bumped your "funny bone?" The "funny bone" is actually a bundle of nerves in your arm.
Nerves react to pain. For example, if you accidentally put your hand on a hot stove, the nerves send a message to the brain, and the brain pulls your hand away.
Skin
Skin is on the surface of your body. It is made up of cells called skin cells. If your skin was taken off, it would cover 5-15 square feet of ground. It is covered in tiny holes called sweat pores. Sweat comes out through these holes. Your skin is also covered with tiny hairs.
Eyes
We use our eyes to see. Light is reflected off objects and goes into our eyes. When we see something, our eyes see it upside down. The image is sent to the brain, and the brain switches it right side up. Our eyeballs are about the size of a golfball. The pupil of the eye is the only part of the eye that can see.
Nose
We use our nose to smell. We cannot see smells. When a smell enters our nose, the nose sends the smell to the brain, which identifies it.
Ears
We use our ears to hear. When a sound enters the ear, it causes the eardrum (three small bones) to vibrate. Hairs turn the vibrations to electrical signals which are sent to the brain.
Bones
If you didn't have bones, you wouldn't have any shape. The outside of a bone is tough and hard, but the inside is soft and spongy. The spongy bit is called bone marrow. Bone marrow makes white blood cells.
Muscles
If you didn't have muscles, you wouldn't be able to move. There are many muscles in the human body. There are leg muscles, arm muscles, hand muscles, feet muscles, and many more.
Muscles are attached to bones by strings called tendons. The largest muscle is the heart. It pumps blood around the body, and never takes a break.
Cells
Red blood cells
Red blood cells are the cells that make your blood look red. They transport oxygen throughout your body.
White blood cells
White blood cells are the police of your body. When it sees a cell that's bad for your body, the white blood cell eats it.
Platelets
Platelets seal up cuts. Whenever you get a cut, platelets will grab the edges of the cut and stick themselves together until the cut is completely sealed.
DNA
DNA is what gives you personality. DNA looks sort of like a twisty ladder. If all your DNA was put end to end, it would stretch to the Sun and back more than 200 times.
The digestive system
Whenever you eat, the digestive system goes into action. There are several sections in the digestive system: the mouth, the esophagus, the stomach, the small intestine, the large intestine, and the anus. The entire digestive system is roughly the length of a school bus.
The mouth
The mouth is the first step in digestion. Your teeth grind food down, and saliva (spit) helps. Then you swallow it, and it goes to the next step in digestion: the esophagus.
The esophagus
The esophagus is a tube that food goes down to reach the stomach. A tissue in the esophagus prevents the food from going down the windpipe. Muscles in the esophagus force the food down.
The stomach
The stomach is the next step in digestion. It has a strong acid in it that breaks down the food even more. The acid could eat right through a piece of wood. Once the food has been ground into a soup-like mush, it gets flushed out of the stomach and into the next step in digestion: the small intestine.
The small intestine
The small intestine is the next step in digestion. It sucks the nutrients out of the food and transports it around the body. But there is still food remaining. This goes on to the final step in digestion: the large intestine.
The large intestine
The large intestine is the final step in digestion. All the moisture is sucked out of the food. The waste is then pushed out of the body by the anus.
The brain and the nervous system
The brain
The brain is the command center of your body. It controls your movements. It makes decisions. It stores you memories. The brain also gives us dreams. It is located in the top part of your head. The skull protects our brain. The human brain is the most advanced brain on the planet.
The nervous system
The nervous system is a series of nerves that travel around the body. They deliver the brain's messages. Have you ever bumped your "funny bone?" The "funny bone" is actually a bundle of nerves in your arm.
Nerves react to pain. For example, if you accidentally put your hand on a hot stove, the nerves send a message to the brain, and the brain pulls your hand away.
Skin
Skin is on the surface of your body. It is made up of cells called skin cells. If your skin was taken off, it would cover 5-15 square feet of ground. It is covered in tiny holes called sweat pores. Sweat comes out through these holes. Your skin is also covered with tiny hairs.
Eyes
We use our eyes to see. Light is reflected off objects and goes into our eyes. When we see something, our eyes see it upside down. The image is sent to the brain, and the brain switches it right side up. Our eyeballs are about the size of a golfball. The pupil of the eye is the only part of the eye that can see.
Nose
We use our nose to smell. We cannot see smells. When a smell enters our nose, the nose sends the smell to the brain, which identifies it.
Ears
We use our ears to hear. When a sound enters the ear, it causes the eardrum (three small bones) to vibrate. Hairs turn the vibrations to electrical signals which are sent to the brain.
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