14-1: The Body s Transport System. 7 th Grade Life Science

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Johnathan Norton
6 years ago
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1 7 th Grade Life Science

2 Cardiovascular System The cardiovascular system, also called circulatory system, is made of your heart blood vessels, and blood. It is like the network of highways on Earth, where delivery trucks deliver and trash trucks take trash away.

3 Cardiovascular System Instead of delivery and trash trucks, you have blood delivering the goods and taking the trash away. It connects ALL parts of your body.

4 What does it deliver? Your blood delivers the oxygen and glucose that your cells need. Also antibodies that fight disease.

5 What does it remove? Your blood removes waste from the cells. When cells use glucose, they produce CO 2. The CO 2 is carried by blood to the lungs where it is exhaled.

6 Fighting Disease Disease fighting cells are transported by blood. They look for invaders or germs to kill. When they fail, you get sick, but your blood also carries messenger cells to help make an army to attack the disease.

7 The Heart The heart moves the blood around the body. It is a hollow, muscular organ made of cardiac tissue. It is found under your sternum beneath the rib cage.

9 The Heart Structure It has a right and left side, separated by a wall called the septum. Each side has two chambers, an upper (atrium) and a lower (ventricle). In the right atrium, a special group of cells called pacemakers send signals for each muscle contraction.

10 How it works 1. Atria relax and fill with blood. 2. Atria contract, pumping blood into ventricles. 3. Ventricles contract, pumping blood into large blood vessels.

11 All along, valves open and close, making a lubdub sound and making sure blood goes the right direction. FYI: Left ventricle exerts much more force than right ventricle.

12 The blood travels Arteries carry oxygen rich blood away from the heart. Blood then goes through tiny capillaries, delivering O 2 and glucose and picking up CO 2. Then it goes into a vein, which takes the low oxygen blood back to the heart.

13 Two Loop System The cardiovascular system is a two loop system. The right side of your heart pumps through loop one and the left side pumps through loop two. Loop 1: Goes to lungs Loop 2: Goes to body

14 Takes less than 1 minute to go through both loops. BTW: The aorta is the largest artery in the body, at the top of the heart.

15 Artery Structure Blood leaves the heart through the aorta artery. The first branch it comes to are the coronary arteries. These take oxygen rich blood back to the heart.

16 Blood then reaches other branches, one to the brain, intestines, and other organs. Arteries are thick, having three layers.

17 Innermost layer is smooth epithelial cells allowing blood to flow easily. The middle layer is muscle tissue. The outer layer is flexible connective tissue.

18 This strong design allows the arteries to contract and relax with each heart beat. Otherwise arteries might burst from the pressure.

19 Pulse If you lightly touch your wrist, you may feel an artery pulsing. This is called your pulse and it moves as each heart beat takes place.

20 Regulating Blood Flow The muscle tissue in your arteries control blood flow. When you eat, arteries to your stomach open wider. Arteries to other body parts narrow.

21 Capillaries Blood eventually leaves small arteries and enters capillaries. These have walls only ONE cell thick. O 2, CO 2, and glucose easily diffuse through the wall.

22 Veins Blood leaves the capillaries and enters larger blood vessels called veins. These lead back to the heart. They have three layers, but they are much thinner the pressure is less.

23 Some larger veins have valves to make sure blood flows toward the heart. Movement of skeletal muscles also helps push blood along.

24 Blood Pressure Like water in a hose, blood pushes on the sides of the blood vessel. High pressure can damage vessels. It can be measured with a sphygmomanometer.

25 Blood Pressure DON T COPY Air is pumped into a cuff wrapped around your arm until the blood stops flowing to your arm. Air is then slowly released. Pressure is measured when the heart ventricles are pumping also when they are relaxed giving two numbers. 120 / 80 is normal (mmhg).

26 Summary The cardiovascular system delivers necessary O2 and nutrients to the body. It also removes waste products like CO2. It has three types of vessels arteries, capillaries, and veins. The heart pumps blood through them. Arteries take blood away from the heart. Veins return blood to the heart.

The Circulatory System:

The Circulatory System: The Body s Transport System The Circulatory System! What is the CIRCULATORY SYSTEM? A HIGHWAY NETWORK that LINKS all parts of your body. Consists of the HEART, BLOOD VESSELS, and