The Circulatory System

1. The Circulatory System T- 1-855-694-8886 Email- [email protected] By iTutor.com

2. Circulatory System The  Circulatory System  is responsible for transporting materials throughout the entire body. It transports nutrients, water, and oxygen to your billions of body cells and carries away wastes such as carbon dioxide that body cells produce . It is an amazing highway that travels through your entire body connecting all your body cells. © iTutor . 2000-2013. All Rights Reserved

3. Components Heart Blood Vessels Arteries Veins Capillaries Heart Blood Arteries Veins © iTutor . 2000-2013. All Rights Reserved Circulatory System

4. Which gases are transported to and from the body’s cells by the blood flowing in the circulatory system ? carbon dioxide oxygen Oxygen is the gas needed for respiration and is transported to the body’s cells. © iTutor . 2000-2013. All Rights Reserved Circulatory System

5. The circulatory system carries two types of blood Arrangement of the circulatory system means that these two types of blood do not mix. Oxygen-rich blood c Oxygen-poor blood Blood travelling to the body cells High oxygen content Low carbon dioxide content Blood travelling away from the body cells Low oxygen content High carbon dioxide content © iTutor . 2000-2013. All Rights Reserved Circulatory System

6. The heart is the organ at the centre of the circulatory system. It pumps blood around the body. © iTutor . 2000-2013. All Rights Reserved Circulatory System

7. The inside of the heart is divided into two sections so that the two types of blood ( oxygen-rich and oxygen-poor ) are kept apart Oxygen-poor blood Right side of the heart Oxygen-rich blood Left side of the heart © iTutor . 2000-2013. All Rights Reserved Circulatory System

8. The Heart: Structures Heart coverings Pericardium Covers the heart and large blood vessels attached to the heart Visceral pericardium Innermost layer Directly on the heart Parietal pericardium Layer on top of the visceral pericardium

9. Pericardium Protective sac of connective tissue Surrounds the heart Filled with fluid © iTutor . 2000-2013. All Rights Reserved The Heart: Structures

10. Heart walls: Epicardium Outermost layer Fat to cushion heart Myocardium Middle layer Primarily cardiac muscle Endocardium Innermost layer Thin and smooth Stretches as the heart pumps © iTutor . 2000-2013. All Rights Reserved The Heart: Structures

11. Myocardium The muscle of the heart Strong and thick Composed of spontaneously contracting cardiac muscle fibers Can conduct electricity like nerves. It’s blood supply comes from the coronary arteries. © iTutor . 2000-2013. All Rights Reserved The Heart: Structures

12. The right and left sides of the heart are separated by a septum , or wall. The septum prevents the mixing of oxygen rich and oxygen poor blood. On each side of the septum are two chambers. The upper chamber (receives blood) is the atrium. The lower chamber (pumps blood out of heart) is the ventricle. © iTutor . 2000-2013. All Rights Reserved The Heart: Structures

13. Four chambers Two A tria Upper chambers Left and right Separated by interatrial septum Two Ventricles Lower chambers Left and right Separated by interventricular septum © iTutor . 2000-2013. All Rights Reserved Right Ventricle Right Atrium Left Ventricle Left Atrium The Heart: Structures

14. The chambers of the heart have different functions: blood to the body blood from the body blood to the lungs blood from the lungs The Atria collect blood that enters the heart . The ventricles pump blood out of the heart . © iTutor . 2000-2013. All Rights Reserved The Heart: Structures

15. The valves between the atria and ventricles are connected to the inner walls of the heart by tough tendons . valve open © iTutor . 2000-2013. All Rights Reserved The Heart: Structures

16. The tendons allow the valves to close and hold the valve flaps in place. They prevent the valves from flipping up and turning inside out valve open valve closed © iTutor . 2000-2013. All Rights Reserved The Heart: Structures

17. A valve acts like a door that only opens in one direction. If the door is held by someone at a fixed point, only the arm moves as the door opens and closes. When the door is closed the arm is fully extended , so the door can only be opened in one direction . © iTutor . 2000-2013. All Rights Reserved The Heart: Structures

18. A valve acts like a door that only opens in one direction. In the heart , the tendons holding the valve are like the arm holding the door. One end of each tendon is fixed to the wall of the heart and so the valve can only open in one direction . © iTutor . 2000-2013. All Rights Reserved The Heart: Structures

19. How does the heart pump blood? The heart can pump blood because it is made of muscle. Muscle tissue works by contracting (squeezing) and relaxing . © iTutor . 2000-2013. All Rights Reserved

20. How does the heart pump blood? All the parts of the heart on either side, work together in a repeated sequence. The two atria contract and relax; then the two ventricles contract and relax. This is how blood moves through the heart and is pumped to the lungs and the body. One complete sequence of contraction and relaxation is called a heartbeat . © iTutor . 2000-2013. All Rights Reserved

21. Blood Vessels As blood moves through the circulatory system it moves through 3 types of blood vessels: Arteries: Carry blood away from the heart . Capillaries: Link arterioles to veins. Veins: Carry blood towards the heart © iTutor . 2000-2013. All Rights Reserved

22. Arteries Large vessels Carry blood from heart to tissues of body. Carry oxygen rich blood, with the exception of pulmonary arteries. Thick walls-need to withstand pressure produced when heart pushes blood into them. © iTutor . 2000-2013. All Rights Reserved Smallest blood vessels Walls are only one cell thick and very narrow. Important for bringing nutrients and oxygen to tissues and absorbing CO 2 and other waste products . Capillaries Blood Vessels

23. Veins Once blood has passed through the capillary systems it must be returned to the heart. Done by veins Walls contains connective tissue and smooth muscle. Largest veins contain one way valves that keep blood flowing toward heart. Many found near skeletal muscles. When muscles contract, blood is forced through veins. © iTutor . 2000-2013. All Rights Reserved

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25. Blood Pressure The heart produces pressure The force of blood on the wall of the arteries is known as blood pressure. Blood pressure decreases as the heart relaxes, but the rest of the circulatory system is still under pressure. © iTutor . 2000-2013. All Rights Reserved

26. Blood Pressure When blood pressure is taken, the cuff is wrapped around the upper portion of the arm and pumped with air until blood flow in the artery is blocked. As the pressure in the cuff is relaxed, 2 numbers are recorded. Systolic pressure- the first number taken, is the force felt in the arteries when the ventricles contract. Diastolic pressure- the second number taken, is the force of the blood on the arteries when the ventricles relax. © iTutor . 2000-2013. All Rights Reserved

27. Blood What percent of your body is blood? How much blood do we contain? On average 4-6 liters We contain about a pint of blood for every 15 pounds of body weight Composition of Blood: What percent of your blood is cellular? What percent of your blood is plasma? 8% 45% 55% © iTutor . 2000-2013. All Rights Reserved

28. Blood Composed of plasma and blood cells Types of Cells are: Red Blood Cells White Blood Cells Platelets © iTutor . 2000-2013. All Rights Reserved Plasma Straw colored 90% water 10% dissolved gases, salts, nutrients, enzymes, hormones, wastes, and proteins.

29. Blood Plasma proteins 3 Types: Albumins, globulins and fibrinogen . Albumins and Globulins - transport substances such as fatty acids, hormones and vitamins. Fibrinogen - Responsible for blood’s ability to clot © iTutor . 2000-2013. All Rights Reserved Red Blood Cells Most numerous type Transport oxygen Get color from hemoglobin Disk shaped Made in red bone marrow Circulate for 120 days

30. White Blood Cells Guard against infection, fight parasites, and attack bacteria Number of WBC’s increases when body is fighting Lymphocytes produce antibodies which fight pathogens and remember them Blood © iTutor . 2000-2013. All Rights Reserved Platelets Aid the body in clotting Small fragments Stick to edges of broken blood cell and secrete clotting factor to help form clot.

31. Blood Blood has 3 main Functions Transport Protection Temperature Regulation © iTutor . 2000-2013. All Rights Reserved Plasma Red Blood Cells Platelets White Blood Cells

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