The Circulatory System The Truth About Your Heart

COOL FACTS The body of an adult contains over 60,000 miles of blood vessels! Strung together end to end, your blood vessels could circle the globe 2 1/2 times! An adult's heart pumps nearly 4000 gallons of blood each day! Your heart beats some 30 million times a year!

What is it? The circulatory system is made up of: –The HEART –The BLOOD VESSELS –BLOOD The circulatory system is your body’s delivery system. It delivers oxygen rich blood to all parts of the body. On the return trip, the blood carries waste products for your body to dispose of.

Your Heart About the size of your fist Composed of mostly muscle Located near the center of your chest Beats about 70 times a minute

The Heart Enclosed in a Protective sac called the pericardium

The Heart The right and left sides of the heart are divided by a wall called the septum. The septum prevents the mixing of oxygen rich blood and oxygen poor blood.

The Heart On each side of the septum are two chambers The upper chamber is called the atrium. It receives blood The lower chamber is called the ventricle. It pumps out blood.

The Heart The heart has a total of four chambers: –2 atria –2 ventricles

The Pathway of blood flow Deoxygenated blood passes from right atrium into right ventricle and then goes to the lungs to pick up oxygen. From the lungs, the oxygenated blood goes back to the heart to the left atrium and then the left ventricle and then pumped to the rest of the body.

The Heart As the heart contracts blood flows through the atrium and out through ventricles Flaps of connective tissue, called valves, are located between the atria and ventricles When blood is flowing the values are open When the ventricles contract, the valves close to stop blood from going back into the atria This system of valves keeps blood flowing in one direction

Diagram of the Heart

Blood Vessels As blood flows through the heart, it flows through 3 types of blood vessels: –ARTERIES –CAPILLARIES –VEINS

Arteries Carry blood Away from heart to body tissues (almost always oxygenated blood) Large vessels with thick walls

Clogged Arteries

Capillaries Smallest blood vessels Microscopic and narrow (one cell thick) Where gas exchange occurs –Capillaries bring oxygen to body tissues and picks up the waste (CO2)

Veins Carry blood back to the heart (almost always deoxygenated blood) Thin walls Have valves to prevent blood flowing backward

Blood Composed of Plasma and blood cells There are 3 types of blood cells: –Red blood cells –White blood cells –Platelets

Plasma “Straw colored” Made up of 90% water 10% dissolved gases, nutrients, proteins, salts, hormones, and wastes

Red Blood Cells Most numerous type Transport oxygen Disk shaped Made in the bone marrow

White Blood Cells Guard against infection and attack bacteria When fighting, the number of WBC in your body increases

Platelets Aid the body in blood clotting Too low-excessive bleeding Too high-blood clots om/watch?feature=pla yer_embedded&v=R- sKZWqsUpwhttp:// om/watch?feature=pla yer_embedded&v=R- sKZWqsUpw

Disorders of the Circulatory System Hypertension (high blood pressure) Arteriosclerosis (fatty deposits-plaque-in walls of arteries) Heart Attack (lack of O2 to heart due to block arteries) Stroke (blockage of blood flow to brain)

PREVENTION What are some things that you can do to prevent diseases of the circulatory system? –Eat healthy foods –Avoid high fat/high cholesterols foods –Exercise regularly –Don’t smoke

Short movie about the heart ?lic=1&article_set=59298&cat_id=20 607