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.

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 Sounds

Normal Heart Sound - YouTube

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

Heart Sounds

Shh!! 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) Arteries2) 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 heart

2) Veins› Veins carry blood TOWARD the heart

3) 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