Cardiovascular SystemAdapted from notes from

Canton Middle School

Heart Facts Your heart is about

the size of your fist. It is made of

muscle. It is on the left side

of your chest. It is protected by

the sternum and ribs.

The Fab Four The heart has 4

chambers that beat in rhythm.

The rhythm is controlled by the pacemaker.

The chambers are separated by valves.

The Fab Four It is split into two sides

—the right and the left—separated by the septum.

The two sides are split into chambers.

The upper chambers are called right and left atrium.

The lower chambers are called right and left ventricles.

With Every Beat of Your Heart The heart beats from

the top to the bottom. The atrium beats then

the ventricle beats. The heart beat is due

to the closing of the valves.

The valves in the heart keep blood flowing in ONE direction.

No back flow!!

How the Heart Works The two sides of the

heart have different jobs.

Right Side—receives blood from the body that is low in oxygen and pumps it to the lungs.

Left Side—pumps oxygen rich blood from the lungs to the rest of the body.

SA Node—the pacemaker SA Node—sinoatrial

node is a group of cells in the heart that create electronic impulses that makes your heart beat.

What does the SA node in the heart do? - Sharecare

Heart SoundsNormal Heart Sound - YouTube

Shh!! Quiet please--we are listening to a normal heart beat.

Heart SoundsShh!! We are listening

to the fetal heart around 16 weeks of pregnancy.

http://www.youtube.com/watch?v=jz5y-rKWkoE

Heart Sounds• This is a heart

murmur.• The sound is

different from that of a normal heart beat.

• This sound occurs because the valves of the heart do not open/close properly.

http://www.youtube.com/watch?v=hYYQdyDXaS8&feature=relmfu

The Bloody Truth There are 3 types of

blood vessels: 1) Arteries

2) Veins3) Capillaries

http://www.youtube.com/watch?v=CjNKbL_-cwA

Vasculature There are 3 types of blood vessels: 1) Arteries

› Carry blood AWAY from the heart2) Veins› Veins carry blood TOWARD the heart3) Capillaries --Link the arteries to the veins and are the SMALLEST of the types.

Vasculature: Arteries Carry blood AWAY from the heart. Have thick muscles around them that

SQUEEZE blood. Are responsible for the PULSE you can

feel. Largest artery is the AORTA.

› It has an inside diameter about the size of your thumb.

Vasculature: Veins Carry blood TOWARDS the heart Do NOT have thick muscles. Do HAVE valves which keeps blood flow

moving and not backing up. Largest vein is the VENA CAVA. Veins are “sandwiched” between

skeletal muscles. Flexing the muscles helps blood flow. This is why we stretch!

Vasculature: Capillaries Capillaries link the arteries and the veins. They deliver oxygen and other nutrients to

the cells. They have very thin walls—about 1 cell thick. This thinness allows material to transferred

easily. This thinness also allows them to be broken

easily. This is why we bruise—broken capillaries

under the surface of the skin!!

The Bloody Truth There are four

components of the blood:1) Plasma2) Red blood cells3) White blood cells4) Platelets

http://www.youtube.com/watch?v=R-sKZWqsUpw

The Bloody Truth: Plasma• Plasma is the liquid

part of the blood.• It makes up 55% of

blood volume.

The Bloody Truth: Red Blood Cells RBCs are disc shaped. They do NOT have a

nuclei. RBCs have a life span

of 120 days. They are made in bone

marrow of long bones. They contain

hemoglobin which carries oxygen and carbon dioxide.

http://www.youtube.com/watch?v=4HH3UXpdIFw

The Bloody Truth: White Blood Cells WBCs fight viruses,

bacteria, etc. Their numbers

increase when infection is present.

WBCs are bigger than RBCs but fewer in number.

WBCs have a much shorter life span than RBCs.

http://www.youtube.com/watch?v=JnlULOjUhSQ

The Bloody Truth: Platelets Platelets are irregularly

shaped fragments. They help to clot blood. They live for 4 to 9

days.Clotting

--Platelets produce a chemical called fibrin.

--Fibrin helps make sticky “spider webs” to help blood clot.

http://www.youtube.com/watch?v=--bZUeb83uU