Natural sciences of Educational applications

Circulatory system

1. The blood

   The circulatory system transports blood throughout the body. Blood takes oxygen from the respiratory system and the nutrients from the gastrointestinal tract. In addition, it collects wastes and transports them to the kidneys in order to expel them through the urine. Likewise, it collects carbon dioxide and transports it to the lungs to expel it through respiration.
   The body of a man has about five liters of blood. It is composed of:
   - Red blood cells are responsible for transporting oxygen. In a drop of blood, there are between 5 and 6 million of red blood cells.
   - White blood cells are larger than red blood cells. There are about seven thousands of them in a drop. They defend the body against infections: they envelop microbes and devour them.
   - Platelets are very small cells. There are about three hundred thousands of them in each drop. Its mission is to plug the wounds of the veins and arteries.
   - Plasma is a colorless liquid consisting of water and dissolved salts. It is responsible for leaving the wastes in the kidneys.

2. Indicate the element of blood: red blood cells, white blood cells, platelets or plasma

They transport the oxygen

They leave the wastes in the kidneys

They plug the wounds

It consists in water and salts

They defend us against infections

They are the most numerous

They devour microbes

3. The circulatory system

It is responsible for distributing blood throughout the body in order to feed it and collect wastes. The parts of this system are: the heart, the arteries, the veins and the capillaries.

4. The heart

It is the main organ of the circulatory system.

It has the size of a fist and has four chambers: two atria at the top and two ventricles at the bottom.

Each atrium connects with the ventricle of its same side through a heart valve.

In the picture, we see a cut heart. The left and right side are opposite as we see them.

5. Arteries, veins and capillaries

Arteries are blood vessels or ducts that transport blood from heart to all organs of the body.

Veins transport blood from the body to the heart.

The capillaries are very fine vessels that directly irrigate the body organs and connect arteries and veins.

In the picture, they are arteries the 3 (from heart to the body) and the 8 (from heart to the lungs) they are veins the 10 (from lungs to heart) and the 5 (from heart to the body) the 4 is capillary.

6. Answers with one of the following words: arteries, veins or capillaries.

They connect veins and arteries
They go from heart to the organism
They go from the organism to the heart
They irrigate body organs

7. Circulation

(Look at the pictures and notice that the left and right side refer to the person of the heart. we see it upside down)

We can distinguish between the "small circulation" among the heart and lungs and the other "big circulation" among the heart and other organs.

Let’s see the travel of the blood:

- Oxygenated blood comes from the lungs and through the pulmonary vein; it reaches to the left atrium.

- It goes from the left atrium to the left ventricle and it sends blood to intestine, kidney and capillaries through the aorta.

- In capillaries, the blood loses oxygen and fills with carbon dioxide (CO₂).

- Through the venae cavae, it comes back to the right atrium. Then, it goes from the right ventricle to the lungs through the pulmonary artery.

- In the lungs, it takes oxygen from the air and leaves the carbon dioxide.

- This oxygenated blood returns to the start of the travel.

8. Answer if these sentences are true or false:

Blood with CO₂ comes from lungs
It goes from the pulmonary vein to the left atrium
It goes from the left atrium to the right ventricle
It goes from the left ventricle to the Aorta artery
It goes from the Aorta to the capillaries
The blood takes oxygen in the capillaries
Blood takes CO₂ in the capillaries
Blood with CO₂ goes to the venae Cavae
It goes from the venae Cavae to the left atrium
It goes from the right atrium to the right ventricle
It goes from the right ventricle to the lungs
It takes CO₂ In the lungs

9. Movements of the heart

The heart muscles constantly make two movements: diastole and systole.

In diastole, the heart widen and therefore the blood enters in the atria through the veins (cavae and pulmonary) and the blood goes to each ventricle of the same side.

In systole, a contraction occurs and the blood of ventricles leaves through the two arteries (Aorta and pulmonary)

10. Señala si este movimiento es diástole o sístole:

El corazón se agranda
El corazón se encoge
Entra sangre por las venas
Sale sangre por las arterias

11. Higiene del aparato circulatorio

Generalmente las enfermedades del aparato circulatorio suelen ser graves, por lo que conviene procurar:

- Hacer ejercicio físico al aire libre, para oxigenar bien nuestra sangre.

- Tomar una alimentación variada (carnes, pescados, verduras y frutas).

- No comer demasiado.

- Que la comida no tenga demasiadas grasas.

- No llevar prendas de vestir demasiado ajustadas.

- Debemos desinfectar las heridas que se produzcan.

12. Señala si estos consejos son correctos o incorrectos:

Hacer poco ejercicio
Comer sólo de algunas cosas
Evitar las grasas
Usar vestidos anchos
Comer mucho
Desinfectar las heridas

®Arturo Ramo García.-Record of intellectual property of Teruel (Spain) No 141, of 29-IX-1999
Plaza Playa de Aro, 3, 1º DO 44002-TERUEL

They transport the oxygen
They leave the wastes in the kidneys
They plug the wounds
It consists in water and salts
They defend us against infections
They are the most numerous
They devour microbes