The circulatory system

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

3.1 Blood

Blood transports everything your body need 

              (heat, nutrients, oxygen, waste products)

Blood contains:

- blood plasma (Proteins- fibrinogen for clotting blood,

         water,                    carbon dioxide

         oxygen                  waste products

         nutrients

Red blood cells

small round discs, 

no nucleus

red pigment: haemoglobin absorb and release oxygen

white blood cells

do not have a fixed shape

do have a nucleus

destroy pathogens

    

platelets

fragments of cells that have broken up

- Clotting when the blood is outside the vessels

Trombosis- clottering of blood in the vessel

Blood vessels 

3 types of blood vessels

arterie, capillarie, vein

Artery

From heart to organs

(red) transport O2

walls are: 
    - thick, firm, elastic

High blood pressure 

Capillaries

Release O2 into organs

Absorb Co2 into bloodstream

- one cell layer tick walls

- white bloodcells can go between the cells into the tissue

Veins

Transport CO2 from organs to the heart

- low bloodpressure

       thinner, less elastic

Includes valves

- The blood can flow in 1 direction

3.3 The heart

the heart is part of the systemic circulation.

It needs O2 (respiration) the coronary arteries provide O2 to the heart. 
The coronary veins brings CO2 back to the heart

the heart 

coronary artery, capillaries, coronary vein

pulmonary circulation /septum,  / systemic circulation

valves 

Cardiac cycle - 70 times a minute= heart rate