The Circulatory System

The Circulatory SystemPumping blood all over your body…

Let’s do an experiment…

Take your first two fingers and hold them out and together, like this:

You can take your pulse on your wrist or directly under your jaw.

When I say “Go!” start counting the number of times that you feel your pulse beat.

Resting Heart Rate

This is how fast your heart is beating while you are resting. Which activities do you think

exemplify a resting state? SHARE!

A normal resting heart rate is between 60 and 80 beats per minute.

Write down this number!

Continued Experiment!

Now we will jog in place for 20 seconds and take our heart rate again. But first, let’s hear some hypotheses!

What do you think will happen to our heart rates?

Start jogging again when I say so…

Why do you think this happened?

Needed Materials

Remember from the respiratory system that your body needs what two elements in order to create energy? Oxygen and glucose

And how does your body make sure that both of these elements get where they need to be? The circulatory system carries them

along.

In Conclusion…

What can we say about why our heart would pump faster when we are exercising?

Good! Our bodies need more energy, so they need more oxygen and glucose and in turn our heart pumps harder to get them there.

The Functions of the Circulatory System1) The circulatory system

carries needed substances (oxygen and glucose) to cells

2) And carries waste products (carbon dioxide and urea) away from cells.

Think of the circulatory system as a “highway” where cars are red blood cells.

The Heart

Your heart is a hollow, muscular organ that pumps blood throughout the body. It DOES NOT make blood.

Each time your heart beats, it pushes blood through the blood vessels of your circulatory system.

Fun Facts!

The heart beats continually throughout a person’s life resting only between beats.

During your lifetime your heart may beat over three billion times.

In one year, it pumps enough blood to fill over 30 competition-size swimming pools.

The Structure of the Heart

Atria

Ventricles

Your heart has 4 chambers:•2 Atria (singular atrium)•2 Ventricles (singular ventricle)

•Atria on top (Arrows point up)

•Ventricles on bottom(Arrows point down)

The Structure of the Heart

Atria

Ventricles

We distinguish between the two atria and two ventricles by calling them right and left.

REMEMBER– The right and left refer to YOUR right and left. As if the heart was in your own chest.

LeftRight

The Structure of the Heart

Atria

The septum is a thick, muscular wall that separates the right and left sides of the heart.

The septum separates the heart

LeftRight

Septum

The Structure of the Heart

Atria

A valve is a flap of tissue that prevents blood from flowing backward.

They separate the atria and the ventricles and are also found in large blood vessels.

LeftRight

SeptumVentricl

es

The Structure of the Heart

Septum

Right Atrium

LeftAtriu

mRightVentricle

LeftVentricle

How the Heart Works

We already know that the heart is made of cardiac muscle.

We also know that muscles need to work in pairs.

The heart relaxes and contracts to do its work.

When the heart relaxes, the heart fills up with blood. When it contracts, the heart pumps blood forward.

See For Yourself…

http://www.ehc.com/vbody.asp

Other Circulatory Organs

Pacemaker – a group of cells which is located in the right atrium which sends out signals that make the heart muscle contract.

A pacemaker is also a small electrical device used to control abnormal heart rhythms.

Blood Vessels Arteries– Blood vessels that carry blood

away from the heart.

ARTERY = AWAY!!!

Arthrosclerosis is a condition in which fatty material collects along the walls of arteries.

Blood Vessels

Veins – Blood vessels that carry blood into the heart

VEINS = IN !! Capillaries– Tiny vessels where

substances ( oxygen and carbon dioxide ) are exchanged

Important Blood Vessels

Vena Cava – the vein that brings oxygen poor blood into the heart.

Aorta – the artery that brings oxygen rich blood away from the heart.

Tricky Blood Vessels!

Pulmonary Vein – brings oxygen rich blood from the lungs and into the heart.

Pulmonary Artery – brings oxygen poor blood away from the heart and into the lungs.

PULMONARY MEANS LUNGS!!!