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Circulatory System

I. OverviewA. Includes heart, blood, and blood vessels

B. Functions of the Circulatory System (CS)

1. Internal transportation system

a. Delivers O2 and nutrients to cells

b. Removes CO2 and other wastes from cells

2. Heart pumps blood throughout the body

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Circulatory System

II. Circulation (Movement of blood)A. Coronary circulation: the flow of blood to

and from the tissues of the heartB. Pulmonary circulation: the heart pumps

oxygen-poor blood to the lungs where it is oxygenated and returned to the heart

C. Systemic circulation: oxygen-rich blood flows from the heart to the organs and tissues of the body, and oxygen-poor blood returns to the heart from the body

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The Circulatory System (DRAW)

Pulmonary Systemic

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III. HeartA. The heart is divided into

two sides by the septum

1. Septum – A thick wall of tissue that separates the heart into left & right sides

2. Prevents oxygen-rich blood from mixing with oxygen-poor blood

Septum

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B. There are four chambers in the heart

1. Two upper chambers are called atriaa. Receive blood from body

and lungs

Right Atrium

Left Atrium

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2. Two lower chambers called ventricles

a. Pump blood to body and lungs

Right Ventricle

Left Ventricle

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3. The atrium & ventricles on the right have oxygen-poor blood returning from the body

Oxygen poor blood

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4. The atrium & ventricles on the left have oxygen-rich blood returning from the lungs

Oxygen rich blood

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C. Blood flows in one direction from atrium to ventricle and is controlled by one-way valves

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Review!

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IV. Blood Vessels (3 Main Types)

A. Arteries1. Carry blood AWAY from the heart to tissues

and organs.

2. Thick walled and muscular WHY?

3. The Aorta is the largest artery, & carries

blood from the heart to the rest of the body. Artery Capillary Vein

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B. Capillaries1. Connect veins & arteries

2. Walls are very thin and porous to exchange materials What materials?

Artery Capillary Vein

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C. Veins1. Carry blood to the heart.

2. Thin-walled and muscular.

3. Many are located near and between skeletal muscles (WHY?)

4. Large veins contain valves to prevent backflow of blood.

Artery Capillary Vein

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D. Blood Pressure

1. Force of blood on the walls of blood vessels

2. Highest in arteries, lowest in veins

3. Rises and falls with heart beat

4. Normal is below 120/80a. First number is systolic (blood is being pumped)

b. Second number is diastolic (heart refills w/blood)

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V. BloodA. General information:

1. Human body contains 4-6 liters2. Carries oxygen (lungs) and nutrients

(digestive system) to body, and carbon dioxide from body to lungs

3. Carries waste products from cells to kidneys4. Fight infection and heals wounds5. There are 4 components to blood:

a. Plasma.b. Red blood cells.c. White blood cellsd. Platelets

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B. Plasma

1. Plasma is the liquid portion of blood.

2. Plasma is 92% water.

3. Plasma carries nutrients, salts, hormones, enzymes, wastes, white blood cells, & red blood cells.

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C. Red Blood Cells (RBC)1. Red blood cells carry

oxygen & carbon dioxide throughout the body.

2. Have hemoglobin which binds to oxygen and carries it in the RBC.

3. RBC’s are made in bone marrow

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D. White blood cells (WBC)1. White blood cells protect the body against

infection.

2. Most are created in bone marrow

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E. Platelets1. Platelets are cell

fragments that help clot blood.

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Whole Blood Sample

Red blood cells

White blood cells

Platelets

Plasma

Sample Placed in Centrifuge

Blood Sample That Has Been Centrifuged

The separation of blood

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VI. Cardiovascular Disease

A. Atherosclerosis1. Atherosclerosis is

caused by fatty deposits which build up on the inner walls of the arteries.

2. The most common cause of heart attacks today

3. Kills over 1 million Americans a year

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B. Hypertension1. High blood pressure

2. Damages blood vessels and makes the heart work harder.

3. Can cause strokes & contribute to heart attacks.

C. Aneurysm1. Weakened, bulging artery

wall; can burst

2. No symptoms!

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D. Stroke1. Interruption of blood to the brain2. Caused by aneurysm, blood clot, or atherosclerosis3. Can lead to partial paralysis or death

E. Risk Factors1. Age2. Gender3. Genetics4. High fat diet5. High blood pressure6. Smoking7. Stress8. Alcohol9. Obesity10. Inactivity