The Circulatory

System

• The human heart beats more than 2.5 billion times in an average lifetime.

• The heart produces enough pressure each time it pumps to squirt blood 30 ft.

• If we connected our arteries, veins, and capillaries together they would cover 60,000 miles. (Over 24,000 miles around the earth 1 time.)

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• Functions of the Circulatory / Cardiovascular System

1.Carries needed materials such as glucose and oxygen to the cells!

2. Carries waste products such as carbon dioxide and water!

3. Carries disease fighters (white blood cells).

Path of red blood cell

3 Parts of the Circulatory System

•1. Heart•2. Vessels•3. Blood

1.Heart

The Heart• 4 Chambers –atriums – 2 upper chambers

ventricles – 2

lower chambers• Valves – Keep

blood from backing up in the chambers.

• Made of muscle• pacemaker – a

group of cells that regulate the heart beat.

Pulmonary Circulation - Refers to the blood flow to the lungs and back to heart.

3 Parts of the Circulatory System

•1. Heart•2. Vessels•3. Blood

2. Vessels

– Arteries

– Veins

– Capillaries

Vessels

• 1. Arteries – Carry blood rich in oxygen away from the heart.

• 2. Veins – Carry blood poor in oxygen back to the heart.

• 3. Capillaries – Materials are exchanged to and from the cells by diffusion. Only 1 cell thick.

If we connected all of our vessels end to end….

we could go around the world almost 3 times!!!

Blood Vessels

• Arteries -blood vessels that carry blood away from the heart. They are thicker to withstand pressure as blood is pumped from heart.

Arteries

• Veins - The blood vessels that carry blood back to the heart .

Veins

• Veins have one-way valves that keep blood moving toward the heart.

Compare Arteries with Veins

• Capillaries - microscopic blood vessels where diffusion takes place to and from cells.

Capillaries

• The walls of capillaries are only one cell thick.

3 Parts of the Circulatory System

•1. Heart•2. Vessels•3. Blood

3. Blood Identify the 4 parts of blood.

Parts of Blood

• plasma

• Platelets

• red blood cells (RBC)

• white blood cells (WBC)

• The amount of blood in an adult would fill five 1-L bottles.

Identify the function of each.

Plasma

• Carries nutrients (glucose) minerals and waste from cells.

• Plasma – mostly water

Red Blood Cells

• Red blood cells contain hemoglobin , a molecule that carries oxygen & carbon dioxide, & gives blood the red color.

Red Blood Cells

• Red blood cells have life span of about 120 days.

• They are made at a rate of 2 million to 3 million per second in the bone marrow.

• Red blood cells wear out and are destroyed at about the same rate.

Blood Cells

• White bloods cells - fight pathogens.

Less of them than RBC’s.

Blood Cells• They destroy bacteria and viruses and absorb

dead cells.

• The life span of white blood cells varies from a few days to many months.

Platelets

• Platelets help clot blood and contain fibrin which forms scabs.

Clotting Blood

• Scab

forming

Platelets

• When you cut yourself, platelets stick to the wound and release chemicals.

• Then substances called clotting factors carry out a series of chemical reactions.

Platelets

• After the clot is in place and becomes hard, skin cells begin the repair process under the scab.

• Fibrin form a sticky net and later a scab.

• This net traps escaping blood cells and plasma and forms a clot.

Blood Clotting

Blood Review• Plasma – 55% of blood and mostly water.

Carries the glucose and other materials from digested food. (yellowish color)

• Red Blood Cells – Produced in the bone marrow and carries oxygen to the cells. Made mostly of hemoglobin.

• White Blood Cells – Carries the bodies disease fighters. Less of them than RBC and larger.

• Platelets – Helps blood to clot & contains fibrin that makes scabs.

Blood

Blood Types

• 4 Types

• A

• B

• AB

• O

Blood Types

• 4 Types

• A

• B

• AB (Least common)

• O (Most common)

Blood Transfusions

• A – Can only rec. A or O• B – Can only rec. B or O• AB – Type AB can rec. A, B, AB, or O.• O – Type O can only rec. O O blood but can give to any blood type and

is considered the Universal Donor.

Blood Disorders

• Anemia – A disorder in RBC where cells in tissue can’t get enough oxygen.

• Leukemia – A disorder where WBC are produced in large numbers.

• The force of the blood on the walls of the blood vessels is called blood pressure.

Blood Pressure

•Blood pressure is measured in large arteries and is expressed by two numbers, such as 120 over 80.

Animated Blood Pressure

Healthy Heart – Blood pressure Virtual Lab

Cardiovascular Health

• A ) Atherosclerosis

• B ) Heart Attack

• C ) Hypertension

Cardiovascular Health

• A ) Atherosclerosis – A condition where fat builds up in the arteries.

• B ) Heart Attack – Blood is blocked from part of the heart.

• C ) Hypertension – High blood pressure

Circulatory System 23 min