• What does the circulatory system do?(What is its function?)

1. Delivers food and oxygen to body cells. 2. Carries carbon dioxide and other waste

products away from cells. 3. The Cardiovascular System4. Three Major Elements – Heart, Blood Vessels, &

Blood1. 1. The Heart- cardiac muscle tissue2. highly interconnected cells3. four chambers

1. Right atrium2. Right ventricle3. Left atrium4. Left ventricle

• LAYERS OF THE HEART3 layers within a sac:

• Endocardium (Inner)• Myocardium (Middle)• Epicardium or

visceral pericardium (Outer) • surrounded by parietal pericardium• Myocardium is the thickest layer• Unique because of the presence of

INTERCALATED DISCSà allows a single stimulation to cause all cardiac muscle fibers to contract.

• The Pericardium The heart is covered by a thin, tough sac called the pericardium.

• MUSCLES WITHIN THE CHAMBERS• PAPILLARY MUSCLES - found within the

chamber walls• Extend into CHORDAE TENDINAE attached to

valves• Anatomy of the heart • The heart has 2 atria (upper chambers).• Both atria have very thin walls used to hold the

blood (waiting room).• The heart has 2 ventricles (lower chambers).• The ventricles have very thick walls (blood is

pumped here). • Valves • The chambers of the heart are separated by

valves.• The valves prevent the flow of blood

backwards. • LOCATION OF THE HEART• Hollow, muscular organ• PMI is at the 5th left MCL• Weighs 1 lb.

• FUNCTIONS of the ♥• Transports O2 from the lungs to

tissues of the body• Delivers nutrients from the GIT to all systems• Carries wastes from tissues to the excretory

system• Serves as a route for hormones, enzymes, and

other chemicals to reach target tissues • Blood Vessels

1. Arteries --carry blood away from the heart --usually spurt blood when cut --all except the pulmonary artery carry oxygenated blood --thick walled and elastic pulse: expansion and contraction of the artery walls in response to the heartbeat Veins --carry blood toward the heart --contain valves --closer to the body surface than the arteries --all except the pulmonary vein carry deoxygenated blood --thinner, less muscular and elastic than arteries --depend upon muscle and diaphragm movements for blood flow Capillaries --most numerous vessels --connect arteries to veins --microscopic, one cell thick walls --site of much exchange between the blood and the intracellular fluid (lymph) by diffusion

• BloodBlood = a connective tissue made up of blood cells and a liquid called blood plasma.

About 7 % of your body mass About 4.5- 5.6 Liters in an adult human

Men = 5.6 Liters Women = 4.5 Liters Pregnant woman = 5.0 Liters

The Functions of BloodDelivers: Picks Up:

- Nutrients - waste à kidneys - Oxygen, Water, minerals - carbon dioxide à

lungs - Hormones and enzymes - heat à skin - pollutants• The Parts of Blood1. Plasma =carries everything

2. Red Blood Cells = (RBC) gas exchange3. White blood Cells = (WBC) fight infection4. Platelets = clotting

• Blood Composition • Plasma 55% (liquid part of the blood); Blood

Cells 45% • Plasma - nonliving• Yellow liquid (92% H2O)• 8 % nutrients, salts, urea, hormones• Carries:

RBC, WBC, Platelets, Carbon dioxide, food and waste• BLOOD CELL TYPES • Red Blood Cells / Erythrocytes

– most numerous – biconcave disc shaped – smaller than white blood cells, larger

than platelets – no nucleus when mature – produced in the red marrow of long

bones – destroyed in the liver and spleen – contain the iron protein compound

HEMOGLOBIN whose chief function is to combine with oxygen and carry it to the cells

• Red Blood Cells- living• 5 million in 1 drop of blood (most common)• Shape = donut • Live approximately 120-125 days

Hemoglobin = oxygen containing pigment Binds to oxygen and carries it to the cells Gives red blood cells its red color• White blood cells- living • AKA- Leukocytes• White blood cells are larger than red blood

cells, but there are less of them.• 8000 in one drop of blood

Function of White Blood Cells surround, engulf and digest bacteria & viruses

(phagocytosis) Attack bacteria and viruses

White Blood cells --largest blood cells--about 8,000 per drop of blood --most are formed in the bone marrow or in the lymph tissue --mostly protect the body against diseases by

forming antibodies or engulfing bacteria Five types – neutrophils, lymphocytes, eosinophils, basophils, and monocytes.

• Platelets- living• Bits of cells also called Neutrophils

• Live for approximately 10 daysFunction of Platelets

creates fibrin = enzyme that helps clot blood (tiny threads seal cuts)

3. Platelets --smallest blood cells

(fragments) --150,000 to 300,000 per drop

of blood --needed for clotting ** In general, the blood is a fluid tissue helping

to maintain homeostasis for all cells in the body.

1. Transport of needed substances to body cells. (oxygen, amino acids, glucose, fatty acids, glycerol, salts, etc.) 2. Transport of wastes from cells. (urea, water, carbon dioxide in the form of the bicarbonate ion) 3. Helps to maintain a constant body temperature. 4. Aids the body in fighting disease.

• BLOOD FLOW THROUGH THE HEART• BODY (SVC & IVC)à RAà tricuspid valve

opensà RVà tricuspid valve closesà RV muscles contractà pulmonary semilunar valves openà pulmonary artery à lungs

• LUNGSà pulmonary vein à LAà mitral valve opensà LVà mitral valve closesà LV muscles contractà aortic semilunar valve opensà aortaà distribution

• 1. Inferior & superior vena cava • 2. Right atrium • 3. Tricuspid valve • 4. Right ventricle • 5. Pulmonary semilunar valve • 6. Pulmonary arteries • (BLOOD TO THE LUNGS – • GAS EXCHANGE) …• 7. Pulmonary veins • 8. Left Atrium • 9. Bicuspid/ mitral valve• 10. Left ventricle • 11. Aortic semilunar valve • 12. Aorta