The circulatory sytem

The circulatory system is made of:

the heart

the blood

the blood vessels

there are 3 types:

arteries

veins

capillaries

-have very thick walls

-have very narrow LUMEN

-carry blood AWAY from the heart

The pressure of the blood is very high.

The artery must be very strong

-have thinner walls

-have bigger lumen

-have VALVES to stop backflow

they carry blood back to the heart

-are only one cell thick

-are extremely narrow

-are where gas exchange happens

they are so small that only one red blood cell can fit through at a time!

- is an organ

- pumps blood around the body

- is made of very strong muscle

tissue

the heart has 4 chambers:

the right atrium

the left atrium

the right ventricle

the left ventricle

The atria are at the top

the ventricles are at the bottom

the bottom of the heart looks a bit like a 'v'

v for ventricles!

Left and right look the wrong way around on a diagram

This is because we are looking at the heart of another person and not our own!

There are 4 main blood vessels that connect the heart to the rest of the body

the aorta carries blood away from the heart to the rest of the body

a for aorta, a for artery!

the vena cava carries blood back to the heart

v for vena cava, v for vein!

pulmonary means something to do with the lungs

the pulmonary artery carries blood away from the heart to the lungs

the pulmonary vein carries blood from the lungs to the heart

there are 4 parts:

red blood cells

white blood cells

platelets

plasma

-carry oxygen

-are biconcave shaped

-have no nucleus

-fight infections

-are part of the immune system

-the liquid part of blood

-carries everything EXCEPT oxygen

-bind to the site of cuts

-make the blood clot

-form scabs