Human Systems

Unit 4 – The Movers and Removers

Language Learning GoalDefine:• Circulatory system• Blood vessel• Artery• Vein• Capillaries• Lymph & Lymphatic System• Excrete & Excretory System• Bladder• Urine & Urethra

Content Learning Goal

• We will learn about three systems that move things through the body and the organs and parts involved in each system.

The Movers and Removers

• All the cells in our bodies need oxygen and nutrients. We will learn what organ systems move these through the body.

• When our cells use oxygen and nutrients, they make waste products. The waste has to come out of our bodies. We will learn how and why our bodies get rid of waste products.

The Stream of Life

• There is something in your body that moves around like a river. It flows to every part of your body and carries things. Do you know what it is?

Blood

• Blood moves all through our bodies in blood vessels.

• Blood vessels are part of the circulatory system.

• The circulatory system moves oxygen and nutrients through the body.

Circulatory System• The heart is a main part of this

system.• All blood flows from the heart

through big blood vessels called arteries.

• The blood carries oxygen from the lungs and nutrients from the small intestine to the cells. As blood gets farther from the heart and closer to the cells, it travels in smaller and smaller blood vessels.

Make a Model of a Heart

• ACTIVITY! See Page 120.• Everyone get ½ cup water, ½ cup flour, one bag

and one straw.• Put the flour and water in the bag and mix it.• Put the straw in the bag and get tape to seal the

straw into the bag.• When you squeeze the bag, the “blood” comes

out of the straw. This is what happens when the heart pumps.

Circulatory System Continued• In the tissues, blood flows in very thin, tiny

blood vessels called capillaries.• Oxygen and blood leave the capillaries

and go to the cells.• Waste products leave the cells and go to

the capillaries.• Now, the blood in the capillaries carries

waste products back to bigger blood vessels called veins. The blood in the veins flows toward an organ…can you guess which one?

Your Lymphatic System

• This is another organ system that moves things through the body.

• “Lymph” is one of the fluids that flow in your bloodstream.

• When blood goes through the capillaries, lymph leaks out and flows through the tissues. It carries things like nutrients to the cells and also carries things away.

Lymphatic System Continued

• What does the lymphatic system take away from the cells back into the bloodstream?

• Yes - Waste products! It also carries away bacteria and germs.

• As lymph moves through the vessels, it passes through “lymph nodes”. These are tiny, round glands that trap and kill germs and bacteria in the lymph.

Lymph Nodes

• You can sometimes feel your lymph nodes.

• When you have an infection, they sometimes swell up because they are full of germs and bacteria they have trapped.

• See the diagram on Page 121 to locate the lymph nodes and lymphatic vessels.

Getting Rid of Wastes

• One waste product we learned about last week was called carbon dioxide. It is what we breathe out.

• There are other waste products that also form in our cells. These are salts, chemicals and water.

• Foods that can’t be digested become waste products as well.

Wastes Continued

• Waste from our food forms in our large intestines in our digestive systems.

• Our bodies have to get rid of the wastes because they are like poisons. If they stay in the body, we get sick and die.

Wastes Continued

• Many organs and organ systems work to excrete waste products from our bodies.

• The digestive system excretes solid waste from the large intestine.

• The respiratory system excretes carbon dioxide when we breathe out.

• The excretory system excretes other waste products that the cells make.

• Look at the diagram on Page 124 to see this system.

Your Excretory System

• Salts, chemicals and water are waste products that our cells make.

• Some of these are excreted through our skin when we sweat, but most leave the body through the excretory system.

• The kidneys are a main organ used in the excretory system.

• Blood is always flowing through the kidneys. When it does, the kidneys take the waste products out of the blood.

Excretory System Continued

• When the kidneys take the waste products out of the blood, they go down the small tubes (see diagram on page 124) and into the bladder.

• The bladder holds waste until the body excretes it. Then the waste passes out of the body through another small tube called the urethra. This waste is called urine.

Review

• Complete the review questions #1-5 on Page 125.