This muscle never stops working… It works when you are asleep… It works when you eat… It really works when you exercise…. What is it????

This muscle never stops working…

It works when you are asleep…

It works when you eat…

It really works when you exercise….

What is it????

The HEART

Located between the lungs in the mid thoracic region

Apex points toward the left hip

Surrounded by a membrane called the

pericardium

Composed of cardiac muscle tissue

The chambers: Left & Right AtriaLeft & Right Ventricles

The valves: Atrioventricular valves = Tricuspid, Mitral, Semilunar valves = Pulmonary & Aortic

The vessels:Pulmonary artery & vein

Superior & inferior vena cavaAorta

The ValvesAllow blood to flow in only one direction

The pulmonary semilunar valve is the doorway between the right

ventricle and the pulmonary artery which carries “dirty”

blood to the lungs

The aortic semilunar valve is the doorway between the left

ventricle and the aorta which carries “clean” blood to the body

The tricuspid valve separates the right atrium and right ventricle

Composed of 3 flaps

The mitral valve (sometimes called the bicuspid valve) separates the

left atrium and left ventricleComposed of 2 flaps

The ValvesAllow blood to flow in only one direction

Valves open as blood is pumped throughHeld in place by chordae tendineae (“heart strings”)

Aorta leaves left ventricle

Pulmonary artery leaves right ventricle

Superior vena cavaenters right atrium

Inferior vena cavaenters right atrium

L Pulmonary veins enters left atrium

Rt Pulmonary veinsenters left atrium

The VesselsSuperior Vena CavaInferior Vena CavaCarry deoxygenated blood from the upper and lower parts of the

body into the heart

Pulmonary ArteriesCarry deoxygenated blood from the heart

to the lungs

Pulmonary VeinsCarry oxygenated

blood from the lungs to the heart

AortaCarries oxygenated blood from the heart

out to the body

Functions to deliver oxygen and nutrients and to

remove carbon dioxide and other waste products

Cardiovascular SystemA DOUBLE PUMP system

Pulmonary CircuitRA RV Pulmonary artery capillary beds of the alveoli

Systemic Circuitcapillary beds of the alveoli LA LV Aorta Body

Oxygen-poor blood (shown in blue) flows from the body into

the right atrium.

Blood flows through the right atrium into the right

ventricle.

The right ventricle pumps the blood to the lungs, where

the blood releases waste gases and picks up oxygen.

The newly oxygen-rich blood (shown in red) returns to the

heart and enters the left atrium.

Blood flows through the left atrium into the left ventricle.

The left ventricle pumps the oxygen-rich blood to all parts

of the body.

Lub If you listen to

your heartbeat, it makes a lub dub

sound.

The lub is when blood is pushed out of the heart into the body and the dub is the

reloading of the heart with more blood ready

to push it out to the body

Dub

Give a tennis ball a good, hard squeeze. You're using about the same amount of force your heart uses to pump blood out to the body. Even at rest, the muscles of the heart work hard--twice as hard as the leg muscles of a person sprinting.

The human heart can create enough pressure that it could squirt blood at a distance of thirty feet.

Scientists have discovered that the longer the ring finger is in boys the less chance they have of having a heart attack.

Heart Facts

Hold out your hand and make a fist. If you're a kid, your heart is about the same size as your fist, and if you're an adult, it's about the same

size as two fists.

Your heart beats about 100,000 times in one day and about 35 million times in a year. During an average lifetime, the human heart will beat

more than 2.5 billion times.

COMPOSITION BOOK• Cut out diagram of heart• Label the major vessels• Label the chambers• Label the valves• Color the areas of deoxygenated blood blue• Color the areas of oxygenated blood red• Answer the following questions in complete sentences on the page below your diagram

1. Why is the cardiovascular system referred to as a “double pump” system?

2. Where does the systemic circuit go?

3. What is the name of the circuit that is responsible for oxygenating the blood?