Chapter 4 The Human BodyTissues to Organs-Many smaller parts in your body work together. Cells are some of these smaller parts. They are the body’s building blocks.

-A tissue is a group of many cells of the same type that work together to perform a certain job.

Skin tissue is made of skin cells. Your skin protects your body. What makes up other types of tissue? Muscle cells make up muscle tissue. Neurons make up nerve tissue.

-An organ is a group of tissues that does a particular job. Each organ in your body is made up of many different kinds of tissue.-Groups of organs that work together to do major jobs for the body are systems.

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The Digestive System

The digestive system breaks down food into nutrients that can be used by the body.

The mouth, esophagus, stomach, and small intestine are parts of the digestive system.

Digestion begins in the mouth. When you chew, your teeth grind up your food. Saliva softens it and begins to break it down. After you swallow, the food travels down the esophagus, a muscular tube that connects your mouth to the next organ, the stomach.

-The stomach is a baglike organ with walls of smooth muscle. The stomach squeezes your food and mixes it with digestive juices. The food becomes almost liquid.

-From the stomach, food passes into another long tube of muscle. This organ is the small intestine. The small intestine adds other digestive juices to the food. When digestion is complete, nutrients pass through the walls of the small intestine into capillaries. Blood carries the nutrients to each cell in the body.

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The Respiratory System-Put your hand on your chest, take a deep breath, and let it out. Do you feel your chest rise and fall? This movement is caused by breathing. A muscle called the diaphragm located below your lungs, causes air to move into and out of your body. The air that comes in contains oxygen your body needs.

-Air travels from your nose or mouth into the trachea . The trachea branches into smaller and smaller tubes that lead into your lungs. There, the tubes end in tiny air sacs, and tiny blood vessels wrap around the air sacs. The air sacs and the blood vessels have thin walls that let gases move through them.

Oxygen that you inhale moves from the air sacs into the blood. Then blood moves to the heart.

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The Circulatory SystemBlood gets oxygen from the lungs. The blood then travels to the heart. The heart pumps the blood through the body.

-A blood vessel that carries blood away from the heart is called an artery .

Arteries keep branching into smaller and smaller blood vessels, until they become capillaries.

- Veins are vessels that return blood to the heart.

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Blood-Can you guess what tissue is needed for both circulation and respiration? That tissue is blood. Blood is a liquid form of connective tissue.

-There are different kinds of blood cells. They all travel in a liquid called plasma. -Red blood cells are shaped like flattened spheres. Their shape allows them to bend and squeeze through tiny capillaries. This is important because red blood cells carry oxygen to all of the body’s cells.

-White blood cells protect the body from illness. When germs enter the body, white blood cells work to destroy them. Some white blood cells attack the germs, and some make proteins that work with attack cells to kill germs.

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How Does Your Body Think and Move?

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The Nervous SystemThe nervous system is very important. None of the other body systems could work without its help.

-Your brain is the control center of your nervous system. There are billions of nerve cells in your brain. Signals from the brain direct your body’s activities.

-Your brain receives information from all parts of your body. Messages from your body travel along nerves to the spinal cord.

-The spinal cord is a bundle of nerve tissue that runs through your backbone to your brain. The brain acts on information it gets from the body. Then it sends messages back out through the spinal cord.Messages to and from the brain travel along nerve cells, or neurons. Groups of neurons are called nerves.

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Skeletal System-Have you ever seen a skeleton? A skeleton may look strange, but the bones of the human body work together to do some very important jobs.

-Bones support your body and give it shape. They help you move, and some bones make blood cells. They also protect the organs inside your body.

-Your skull, for example, protects your brain from injury.

-Your ribs protect your heart and lungs.

-A bone is a hard organ. The outer part is hard, smooth, and strong. This part helps your bones support your body. It gives your body its shape.

The center of many bones has marrow, tissue that makes red blood cells.

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The Muscular System-Your muscular system is made up of muscles that work together to carry out many jobs.

A muscle is a body part that’s made up of bundles of long fibers. Many muscles work with bones to help you move. Other kinds of muscles do other work.

-Skeletal muscles help you move. They work by pulling on bones.

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The digestion process begins in which of the following:

A.stomach B.mouth

C.small intestine D.large intestine

11-Which list gives the correct order of food travelling through the digestive system after it is swallowed? A stomach, esophagus, large intestine, small intestine B small intestine, large intestine, esophagus, stomach C esophagus, stomach, large intestine, small intestine D esophagus, stomach, small intestine, large intestine

12-A group of organs that work together to carry out life process is an

A.cell B.organ system

C.organ D.tissue

13-A group of tissues that work together to perform a function is

A.cell B.organ system

C.organ D.tissue

21. Which body system exchanges oxygen and carbon dioxide betweenthe body and the environment?A. excretory system B. circulatory systemC. respiratory system D. nervous system

22. The muscles that work with the skeleton to move the body are called

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A. skeletal muscles B. cardiac musclesC. involuntary muscles D. smooth muscles

24-The following picture shows the human circulatory system.

What is the function of the organ marked as X?

A-to filter blood B-to pump blood C-to add oxygen to the blood D-to remove carbon dioxide from the blood

2-Complete each sentence with the correct term.diaphragm-artery-stomach-esophagus1-A(n) carries blood away from your heart.2-The is a bag-shaped organ that mixes your food with digestive juices.3-The is a muscle that helps your body draw air in and out of your lungs.4-The is a tube that connects your mouth to your stomach.

3- Put the following events about circulation in the correct sequence. Number the events 1 to 4.

The heart pumps blood to all parts of the body.

Oxygen-poor blood travels from the heart to the lungs.

Veins carry blood from the body back to the heart.

An artery carries oxygen-rich blood from the lungs to the heart.

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4-Use this space to complete the graphic organizer

6-Match the clue on the left to the term on the right. Write the letterin the blank.1-tissue that connects muscles to bones A. ligament

2-a bundle of nerve tissue that runs through B. tendonyour backbone to your brain

3-a place where bones meet C. joint 4-tough, stringy tissues that connect bones to D. spinal cordeach other

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7-Put the following events in the correct sequence to show how the nervous system works. Number the events 1 to 4. A message is sent to the brain through the spinal cord. You remove your hand from the hot light bulb. The brain sends a message back down the spinal cord. You begin to unscrew a hot light bulb to change it, and yourhand gets burned.

8-Label the digestive system:stomach-Eophagus-small intestine-Mouth-large intestine.

1- .

2- . 3- .

4- .

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5- .

9-Label the following skeleton and answer the following questions:Rib cage-skull-backbone

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