the c ardiovascular system

14
The Cardiovascular System

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The C ardiovascular System. Functions. Delivery of needed materials : Blood transports oxygen from your lungs to your other body cells. It also transports the glucose your body cells use to produce energy. Functions. - PowerPoint PPT Presentation

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Page 1: The  C ardiovascular System

The Cardiovascular System

Page 2: The  C ardiovascular System

Functions□Delivery of needed materials:

Blood transports oxygen from your lungs to your other body cells. It also transports the glucose your body cells use to produce energy.

Page 3: The  C ardiovascular System

Functions□Removing waste products: Blood

carries carbon dioxide (a waste product from the break down of glucose) to the lungs so it can be exhaled.

Page 4: The  C ardiovascular System

Functions□Fighting disease: The cardiovascular

system transports cells that attack disease- causing organisms.

Page 5: The  C ardiovascular System

□The cardiovascular system is composed of:□Heart□Arteries□Capillaries□Veins

Page 6: The  C ardiovascular System

The Heart□The heart is a hollow, muscular

organ that pumps blood throughout the body.

□The right side of the heart is completely separated from the left side by a wall of tissue called the septum. Each side has two chambers.

Page 7: The  C ardiovascular System

□ Each upper chamber is called atrium (plural atria). Blood enters the heat through the atria.

□ Each lower chamber is called ventricle. Blood leaves the heart through the ventricles.

□ In the right atrium there is a group of cells called the pacemaker, which sends out signals that make the heart muscle contract.

Page 8: The  C ardiovascular System

How the heart works1. The cardiac muscle relaxes

allowing blood to flow into the atria.

2. Then the atria contract, squeezing blood through the valves and into the ventricles.

3. Next the ventricles contract, closing the valves between the atria and ventricles and squeezing blood into the large blood vessels.

Page 9: The  C ardiovascular System

A two loop system□The circulatory system has two

loops.□In the first loop, oxygen poor blood

travels from the heart to the lungs, then back to the heart as oxygen rich blood.

□In the second loop, oxygen rich blood is pumped from the heart throughout the body, then back to the heart as oxygen poor blood.

Page 10: The  C ardiovascular System

1. Oxygen rich blood leaves the heart through the left ventricle

2. Oxygen poor blood enters the heart through the right atrium

3. Oxygen poor blood leaves the heart through the right atrium

4. Oxygen rich blood enters the heart through the left atrium

Page 11: The  C ardiovascular System

Arteries

□When blood leaves the heart it travels through arteries.

□The walls of the arteries are generally very thick. (3 cell layers: one layer of epithelial cells, one layer of smooth muscle cells and one layer of connective tissue cells)

□Arteries regulate blood flow, adjusting the amount of blood sent to different organs

Page 12: The  C ardiovascular System

Capillaries□Blood flow from small arteries enters

the capillaries.□In the capillaries materials are

exchanged between the blood and the body’s cells.

□Capillary walls are only one cell thick.

Page 13: The  C ardiovascular System

Veins□After blood moves through the

capillaries, it enters larger blood vessels, which carry blood back to the lungs.

□The walls of veins are also three cells thick, with muscle in the middle layer. However they are much thinner than arteries.

Page 14: The  C ardiovascular System

What is blood pressure□Blood pressure is the force blood exerts

against the walls of the blood vessel.□Blood pressure is measured using a

sphygmomanometer, and is expressed as millimeters of mercury.

□The first number is the pressure while the ventricles contract and pump blood into the arteries.

□The second number measures blood pressure while the ventricles relax.