Circulatory System

What is the circulatory system?

The body's breathing system

The body's system of nerves

The body's food-processing system

The body's blood-transporting system

From what source do cells get their food?

Blood

Oxygen

Other cells

Carbon dioxide

Why is oxygen important to blood and to the cells?

	Oxygen helps the blood to clot.
	Oxygen brings food to the cells.
	Oxygen is necessary for cell growth and energy.
	Oxygen is not important -- carbon dioxide is the most important substance to the body.

Which type of blood vessels carries blood away from the heart?

Veins

Arteries

Capillaries

Arteries, veins and capillaries

Why is blood that flows from the lungs to the heart bright red rather than dark red?

	Oxygen makes it red.
	Carbon dioxide makes it red.
	Gastric juices produce the red colour of the blood.
	The lungs add a pigment (dye) to blood as it flows through them.

What part of the blood carries minerals, vitamins, sugar, and other foods to the body's cells?

Plasma
Platelets
Red corpuscles
White corpuscles

What is the main job of the red corpuscles in the blood?

	To clot blood
	To fight disease
	To transport oxygen to the body's cells and carry away carbon dioxide from the cells
	To transport carbon dioxide to the body's cells and carry away oxygen from the cells

Which of the following can best be compared to soldiers?

Lungs

Capillaries

Red blood cells

White blood cells

Which element in the blood is round and colourless?

Plasma

Platelets

Red blood cells

White blood cells

What would happen to people who have an open wound and whose blood did not clot naturally?

They may bleed to death.

Nothing. Clotting is not important.

They would have to take regular doses of plasma.

They would have to take regular doses of platelets.

What happens when a clot occurred in an undamaged blood vessel?

	You would bleed to death.
	A scab will form on the skin surface.
	Platelets stick to the edges of the cut and to one another, forming a plug.
	The flow of blood to tissues beyond the clot may be cut off.

What happens to blood when it is pumped into the thin-walled blood vessels of the lungs?

	Platelets are exchanged for plasma.
	Carbon dioxide is replaced with oxygen.
	Blood fills the lungs and causes coughing.
	Nothing -- the lungs are just a place blood goes through on its way back to the heart.

What is the function of the blood vessels and capillaries?

	They pump blood to the heart.
	They filter impurities from the blood.
	They carry blood to all parts of the body.
	They carry messages from the brain to the muscles.

Why does blood turn dark red as it circulates through the body?

	It starts to clot.
	It gets old and dirty flowing through the body.
	The oxygen in it is replaced with carbon dioxide.
	The farther blood is from the heart, the more dark red it is.

How many major types of blood have scientists discovered?

One: Type "O"

Two: white cells and red cells

Three: white cells, red cells, and plasma

Four: Types A, B, AB, and O

What is the organ that pumps blood all throughout the human body?

The lungs

The heart

The kidneys

The blood vessels and capillaries

~ How the heart works ~

1. The heart receives oxygen-deficient blood (see the white arrows) from the body into the right upper atrium.
   
   
2. When the heart contracts, the right lower ventricle will pump the blood into the lungs, where the carbon dioxide is exchanged for oxygen.
   
   
3. After the exchange, the blood containing fresh oxygen flows into the left upper atrium.
   
   
4. Oxygen-rich blood (see the black arrows) flows from the left upper atrium into the left lower ventricle.
   
   
5. When the heart contracts, the left lower ventricle will force the blood out to the body through a network of arteries.

Crossword Puzzle on "The Circulatory System"

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Copyright by Alan & Hui Meng