1. Cardiovascular Notes Cardiovascular System
A. The Cardiovascular System is also called the circulatory system.
B. Carries needed substances to cells
1. Carries oxygen from the lungs to the body cells.
2. Carries glucose to your cells to produce energy.
C. Picks up wastes from cells.
1. Carries carbon dioxide to the lungs, where it is exhaled.
D. Blood contains cells that fight disease
1. Transports cells that attack disease-causing microorganisms.

2. II. The Heart is a muscular organ that pumps blood throughout the body
II. The Heart is a muscular organ that pumps blood throughout the body. It is the size of your fist.
A. The right side of the heart is completely separated from the left side by a wall of tissue called the septum.
B. The heart has 4 chambers
C. An upper chamber is called an atrium, while a lower chamber is called a ventricle.
D. The atria are separated from the ventricles by valves, a flap of tissue that prevents blood from flowing backwards. The heart has 4 valves.
E. There are 2 main phases of action with the heart.
1. In one phase, the heart muscle relaxes and the heart fills with blood.
2. In the other phase, the heart muscle contracts and pumps blood forward.

3. F. The pacemaker is a group of heart cells that sends out signals that make the heart muscle contract.
1. If the heart’s pacemaker is damaged, an artificial one is implanted beneath the skin and is connected by wires to the heart.
III. Two Loops
A. Blood flows through the body in the shape of the number 8. The heart is at the center where the two loops cross.
B. In the first loop, blood travels from the heart to the lungs and then back to the heart.
C. In the second loop, blood is pumped from the heart throughout the body and then returns again to the heart.
D. The major artery that distributes oxygenated blood to the rest of the body is called the aorta.

4. IV. Blood Vessels - You have thousands of miles of blood vessels throughout your body to transport blood.
A. Arteries are the vessels that carry blood away from the heart.
1. Artery walls are very thick and consist of 3 layers.
2. Your pulse is caused by the expansion and relaxation of the artery wall.
3. When you count the number of times an artery pulses beneath your fingers, you are counting heartbeats.
B. Capillaries are tiny blood vessels where materials are exchanged between the blood and the body’s cells.
1. Capillary walls are only one cell thick.

5. C. Veins are blood vessels which carry blood back to the heart.
1. The walls of veins have 3 layers, with muscle in the middle layer.
2. Blood inside the veins is usually dark red in color because it has little oxygen in it.
V. Blood Pressure
A. Blood pressure is caused by the force with which the ventricles contract.
B. Blood pressure is expressed as a fraction.
1. The top number is called the systolic number and is a measure of the blood pressure while the heart’s ventricles contract and pump blood into the arteries.
2. The bottom number is called diastolic, which measures the blood pressure while the ventricles relax.

6. VI. Blood is made up of four components: plasma, red blood cells, white blood cells, and platelets.
A. Plasma is the liquid part of the blood.
1. Made up of 90% water.
2. Carries nutrients like glucose, fats, vitamins, and minerals.
3. Many wastes are carried away by plasma.
B. Red Blood Cells take oxygen in the lungs and deliver it to cells throughout the body.
1. Produced in the bone marrow.
2. Mostly made of hemoglobin, a protein that contains iron and causes cells to be bright red.
3. Live for about 120 days

7. C. White Blood Cells - fight diseases.
1. Fewer white blood cells than red blood cells, only one for every 500-1,000 red blood cells.
2. Contain nucleus, unlike red blood cells.
3. Can live for months or even years.
D. Platelets cells - cell fragments that help blood to clot.
1. Collect and stick to the vessel at the site of the wound.
2. Produces a protein called fibrin that weaves a net of fibers across the cut in the blood vessel.
3. Eventually, a blood clot forms

8. VII. Blood Types
A. There are 4 types of blood: A, B, AB, O.
B. Blood types are determined by proteins called marker molecules.
C. The marker molecules on your red blood cells determine your blood type and the type of blood that you can safely receive in transfusions.
D. Type O is called the Universal Donor because it can be donated to all other blood types.
E. Type AB is called the Universal Recipient because it can receive all blood types safely.
VIII. The Lymphatic System is a network of vein like vessels that returns the fluid to the bloodstream.
A. Lymph is fluid that consists of water, dissolved materials like glucose and white blood cells.
B. Lymph nodes filter lymph, trapping bacteria and other disease-causing microorganisms in the fluid.

9. IX. Cardiovascular Health is the leading cause of death in the United States.
A. Atherosclerosis is a condition in which an artery wall thickens as a result of the buildup of fatty materials.
1. One of the fatty materials is called cholesterol, a waxy substance.
2. Results in a reduced flow of blood in the affected artery.
3. May lead to a heart attack if it affects a coronary artery.
4. Heart attacks occurs when blood flow to part of the heart muscles is blocked. Cells die and the heart can be permanently damaged.
a. Some warning signs area chest pain that shoots down the left arm, dizziness, sweating, shortness of breath, and nausea.

10. 5. Treatment for atherosclerosis includes a low fat diet and a moderate exercise program. Medications can be used to lower the levels of cholesterol and fats in the blood. Finally, surgery or other procedures may be used to unclog the blocked arteries.
a. Angioplasty uses a deflated balloon to open up a clogged artery. The balloon stretches the walls of the vessel so the blood can flow through easily.
b. Bypass surgery is performed when there is a blockage in a major artery. A vein is used to replace the blocked artery. It is attached to the aorta and the blocked artery. This surgery allows blood to skip the blocked part of the artery.
B. Hypertension or high blood pressure is a disorder in which a person’s blood pressure is higher than normal, usually greater than 140/90.
1. It is sometimes called the silent killer because often there are no obvious symptoms.
2. Exercise and foods low in sodium can help people who have hypertension.
3. Medication is a last resort to reduce high blood pressure.