The Human Body Systems

The Body Systems

Everyone is different. We have different skin colors, hair colors, body shapes and sizes — but we all look alike inside. If you could peek inside your own body, what would you see? Hundreds of bones, miles of blood vessels, and trillions of cells, all of which are constantly working together, doing all kinds of different things.

The Human Body Systems Work Together

The Digestive System The Skeletal System The Circulatory System The Muscular System The Nervous System The Respiratory System

The Digestive System

The Digestive Tract

First Organs of the Digestive Tract

The mouth and teeth are the first organs of the digestive tract.  The teeth are bones

whose main purpose is to grind food into bits that the body can digest. 

Saliva helps begin to break down food.  

The Esophagus

The esophagus runs from the pharynx to the stomach. 

The esophagus is about 25 cm ( 10 inches) long. 

The esophagus is really a large muscle which pushes food down to the stomach. 

The Stomach

The stomach is a J- shaped muscle.  The stomach acts as a churn.   Chemical breakdown of food begins in the

stomach.

The Small Intestine The small intestine is the main organ of the of the

digestive tract. 

The small intestine absorbs processed food into the bloodstream to deliver to the cells.  The unabsorbed food then passes to the large intestine.

The Large Intestine.

The large intestine is about 5 feet long. The main job of the large intestine is absorb

water and to get rid of unwanted materials.    

The Skeletal System

The Skeletal System is made up of bones, ligaments, and tendons.

Function of the Skeletal System Protects our vital organs

such as the brain, the heart, and the lungs.

Gives us the shape that we have. Without it, we would just be a blob of blood and tissue on the floor.

Allows us to move. Because our muscles are attached to our bones, when our muscles move, they move the bones, and we move.

How Bones Work

Our bones don't work on their own. The bones join together to form joints. The end of each bone is covered by a tough, smooth shiny substance called cartilage that works like oil in a car. All of this is so your bones won't scratch and bump against each other when you move. Our bones are held together by strong stretchy bands called ligaments.

Interesting Facts The smallest bones in the body are found in the ear. The longest bone in the body is the femur. The bones are filled with something called bone marrow

which makes red and white blood cells. Over half the body's bones are in the hands and feet. The only joint-less bone in your body is the hyoid bone in

your throat. As your bones grow, you get taller. When you were born, your skeleton had around 350 bones.

By the time you become an adult, you will only have around 206 bones. This is because, as you grow, some of the bones join together to form one bone.

The Circulatory System

Circulatory System

The circulatory system consists of the heart, blood vessels, and blood.

The heart is a muscular organ about the size of a fist.

It beats about 70 to 90 times a minute, pumping blood though the blood vessels.

The Heart

The heart has two sides, right and left, separated by a thick muscular wall. Each side has two chambers.

The Muscular System

There are more than 600 muscles in the human body.

The Function of Muscles

Muscles help you do almost everything — from pumping blood throughout your body to lifting heavy objects.

You control some of your muscles, and others, like your heart, do their jobs without you thinking about them at all.

How Muscles Work

Muscles work in a very simple way. All they do is tighten up--that is, contract--and relax.

You have two sets of muscles attached to many of your bones which allow them to move.

Muscles can only pull. They never push.

The Nervous System

The main parts of the Nervous System are the Brain, the Nerves, and the Spinal Cord.

The Nervous System

The spinal cord is the main pathway for information connecting the brain and peripheral nervous system.

The human spinal cord is protected by the bony spinal column.

The spinal column is made up of bones called vertebrae.

Nerves

All through our body there are nerves which connect to the spinal cord.

This is called the nervous system. Messages from the nerves travel to the spinal cord, which sends them to the brain.

The brain works out what the messages are so we know what we are seeing, touching, hearing, and tasting, and if something hurts or feels.

The Spinal Cord

We each have a backbone, called a spine. Inside it there is a spinal cord. The spinal cord joins the brain at the top of our neck. Its main function is to serve as a pathway for the messages from the nerves to travel to the brain and back so we know what we are seeing, touching, hearing, and tasting, and if something hurts or feels.

The Brain

Inside our head is the brain. It controls how our bodies work and is protected by the a thick bone called the skull.

The brain makes sure our hearts keep beating and our lungs keep working without us having to think about it.

Part of the brain makes our muscles work. The biggest part of the brain makes us

think, see, hear, feel and taste.

Respiratory System

Function of the Respiratory System

The primary function of the respiratory system is to supply the blood with oxygen in order for the blood to deliver oxygen to all parts of the body.

The main parts of the Respiratory System are the Nose, Mouth, Lungs, Trachea, Diaphragm.

When you Breathe

Did you know that when you breath, air goes through your Respiratory System? The Respiratory System is made up of your nose, throat, trachea, and lungs.

Take Care of Your Respiratory System!

Don’t smoke. Smoking damages your Respiratory System.

Exercise to strengthen your breathing muscles.

If you ever have trouble breathing, tell an adult at once.

Smoking Damages Your Lungs

Do you smoke?If you smoke this is what your lungs will look like.

If you don't smoke this is what your lungs will look like.