Circulatory System

1. Circulatory System

2. The 3 main parts of the circulatory system The Heart The blood vessels Blood

3. Two Pathways • Pulmonary Circulation • Carries blood to lungs and back • Systemic Circulation • Carries blood to body and back

4. Capillaries of head and arms Superior vena cava Pulmonary artery Aorta Pulmonary vein Capillaries of left lung Capillaries of right lung Inferior vena cava Capillaries of abdominal organs and legs

5. The 3 main parts of the circulatory system The Heart The blood vessels Blood

6. Circulatory System HEART

7. The Heart Chambers of the Heart The heart is actually two separate pumps. The left side pumps blood to the body (systemic circulation) The right side pumps blood to the lungs (pulmonary circulation)

13. Aorta Brings oxygen-rich blood from the left ventricle to the rest of the body Superior Vena Cava Large vein that brings oxygen-poor blood from the upper part of the body to the right atrium Pulmonary Arteries Bring oxygen-poor blood to the lungs Pulmonary Veins Bring oxygen-rich blood from each of the lungs to the left atrium Pulmonary Valve Prevents blood from flowing back into the right ventricle after it has entered the pulmonary artery Aortic Valve Prevents blood from flowing back into the left ventricle after it has entered the aorta Mitral Valve Prevents blood from flowing back into the left atrium after it has entered the left ventricle Tricuspid Valve Prevents blood from flowing back into the right atrium after it has entered the right ventricle Inferior Vena Cava Vein that brings oxygen-poor blood from the lower part of the body to the right atrium The Structures of the Heart Left Atrium Right Atrium Left Ventricle Septum Right Ventricle

14. Types of blood vessels • Arteries • Carry blood away from the heart • The Aorta is the largest artery • Veins • Carry blood away from the heart • veins contain valves • the vena cava is the largest veins • Capillaries • - Known as the ‘Distribution Pipes”

16. Arteries Arteries have a thick, elastic layer to allow stretching and absorb pressure. The wall stretches and recoils in response to pumping, thus peaks in pressure are absorbed. The arteries maintain pressure in the circulatory system much like a balloon maintains pressure on the air within it. The arteries therefore act as pressure reservoirs by maintaining (storing) pressure. The elastic layer is surrounded by circular muscle to control the diameter and thus the rate of blood flow. An outer layer of connective tissue provides strength.

17. Arteries:carries blood Away from heart • Large • Thick-walled, Muscular • Elastic • Oxygenated blood • Exception Pulmonary Artery • Carried under great pressure • Steady pulsating Arterioles: smaller vessels, enter tissue

18. Artery vs. Vein

19. Veins The diameter of veins is greater than that of arteries. The blood pressure in the veins is low so valves in veins help prevent backflow.  The contraction of skeletal muscle squeezes the veins and assists with moving blood back to the heart. The vena cava returns blood to the right atrium of the heart from the body. In the right atrium, the blood pressure is close to 0. Varicose veins develop when the valves weaken. Veins act as blood reservoirs because they contain 50% to 60% of the blood volume. Smooth muscle in the walls of veins can expand or contract to adjust the flow volume returning to the heart and make more blood available when needed.

20. Veins:Carries blood to heart • Carries blood that contains waste and CO2 • Exception pulmonary vein • Blood not under much pressure • Valves to prevent much gravity pull Venules: larger than capillaries

21. Capillaries • Smallest vessel • Microscopic • Walls one cell thick • Nutrients and gases diffuse here

22. Blood consists of three types of cells: oxygen-bearing red blood cells, disease-fighting white blood cells, and blood-clotting platelets, all of which are carried through blood vessels in a liquid called -----------. Plasma is yellowish and consists of water, salts, proteins, vitamins, minerals, hormones, dissolved gases, and fats.

23. _________ have thicker walls than veins to withstand the pressure of blood being pumped from the heart. Blood in the veins is at a lower pressure, so veins have one-way valves to prevent blood from flowing backwards away from the heart. ___________ the smallest of blood vessels, are only visible by microscope—ten capillaries lying side by side are barely as thick as a human hair. If all the arteries, veins, and capillaries in the human body were placed end to end, the total length would equal more than 100,000 km (more than 60,000 mi)—they could stretch around the earth nearly two and a half times.

24. Three types of blood vessels form a complex network of tubes throughout the body. __________ carry blood away from the heart, and _________carry it toward the heart. ____________are the tiny links between the arteries and the veins where oxygen and nutrients diffuse to body tissues. The inner layer of blood vessels is lined with endothelial cells that create a smooth passage for the transit of blood. This inner layer is surrounded by connective tissue and smooth muscle that enable the blood vessel to expand or contract. Blood vessels expand during exercise to meet the increased demand for blood and to cool the body. Blood vessels contract after an injury to reduce bleeding and also to conserve body heat.

25. The composition of blood • The plasma (Fluid) – makes up 55% of the blood volume • The solids (cells) – makes up 45% of the blood volume • Blood Plasma (fluid) • 97% water • other 3% (antibodies and protein & nutrients and wastes) • Blood Solid (cells) • Red Blood Cells – Carry O2 and contain hemoglobin • White Blood Cells – Attack bacteria & other invaders • Platelets – Control the blood clothing process

26. Liquid Portion Carries • Blood cells • Erythrocytes (RBC - red blood cells) • Leucocytes (WBC - white blood cells) • Platelets (non cellular particles) • Proteins • Enzymes • Hormones – Endocrine System • Nutrients - Digestive System • Gases - Respiratory System • Inorganic salts

27. Blood is made up of a number of types of cells: Plasma: Plasma is a straw-coloured fluid in which blood cells are suspended. It is made up of approximately 90% water as well as electrolytes such as sodium and potassium and proteins. Red Blood Cells (Erythrocytes): The main function of red blood cells is to carry oxygen. RBC's contain a protein called Haemoglobin. This combines with oxygen to form Oxyhaemoglobin. Each RBC has a lifespan of approximately 120 days before it gets broken down by the spleen. New RBC's are manufactured in the bone marrow of most bones. There are approximately 4.5-5 million RBC's per micro-litre of blood. White Blood Cells (Leucocytes): There a number of types of white blood cells, although the function of all of them is to help fight disease and infection. They typically have a lifespan of a few days and there are only 5-10 thousand WBC's per micro-litre of blood. Platelets (Thrombocytes): Platelets are disc shaped cell fragments which are involved in clotting the blood to prevent the excess loss of body fluids.

28. Red Blood cells

29. Erythrocytes (RBC) • Transporters of • Oxygen • Carbon Dioxide • RBC • Lack a nucleus • Contain hemoglobin • Disk-shaped • RBC are produced in red bone marrow of • ribs, • humerus, • femur, • sternum, and other long bones • Lives for 120 days • Old RBC are destroyed in liver and spleen

30. Leukocytes (WBC) • WBC fight infection • Attack foreign substances • Less abundant • Large cells • Some live for months • Most just a few days • Several types • ALL contain nuclei

31. Platelets • PLATELETS are for CLOTTING blood • Cell fragments • Produced in bone marrow • Short life span (1 week) • Fibrin (sticky network of protein fibers) • Form a web trapping blood cells

32. The Blood • Body contains 4-6 L • Consists of • Water • Red Blood Cells • Plasma • White blood cells and platelets

33. Plasma Platelets White blood cells Red blood cells Whole Blood Sample Sample Placed in Centrifuge Blood Sample That Has Been Centrifuged

34. Plasma Platelets White blood cells Red blood cells Whole Blood Sample Sample Placed in Centrifuge Blood Sample That Has Been Centrifuged

35. Plasma Platelets White blood cells Red blood cells Whole Blood Sample Sample Placed in Centrifuge Blood Sample That Has Been Centrifuged

36. Parts of the Blood

37. Blood Clotting Break in Capillary Wall Blood vessels injured. Clumping of Platelets Platelets clump at the site and release thromboplastin. Thromboplastin converts prothrombin into thrombin.. Clot Forms Thrombin converts fibrinogen into fibrin, which causes a clot. The clot prevents further loss of blood..

38. What is the function of blood?? 1. Transportation: The blood carries other substances around the body inside arteries, veins and capillaries. These include gasses (Oxygen and Carbon Dioxide), waste products (water, urea), hormones, enzymes and nutrients (glucose, amino acids, vitamins and minerals). The blood flows through the circulatory system. 2. Maintaining Homeostasis: Altering the blood flow to the skin can help to reduce body temperature. Transportation of enzymes which are used to maintain our internal environments. 3. Immunity and defense: White blood cells fight infection and platelets help repair damage and clot the blood

39. What is the circulatory system? - transports food, hormones, metabolic wastes, and gases (oxygen, carbon dioxide) to and from cells. Components of the circulatory system include: BLOOD: consisting of liquid plasma and cells BLOOD VESSELS (vascular system): the "channels" (arteries, veins, capillaries) which carry blood to/from all tissues. Arteries carry blood away from the heart. Veins return blood to the heart. Capillaries are thin-walled blood vessels in which gas/ nutrient/ waste exchange occurs. HEART : a muscular pump to move the blood

40. What is the circulatory system? carries blood and dissolved substances to and from different places in the body. The Heart has the job of pumping these things around the body. The Heart pumps blood and substances around the body in tubes called blood vessels. The Heart and blood vessels together make up the Circulatory System.

41. No Circulatory Systems • In simple organisms in moist environments

42. Circulation • Movement of fluid through an organism • Circulatory system • Transport system • Uses fluid to move substances

43. Respiratory system via Circulatory system The arteries, veins, and capillaries are divided into two systems of circulation: systemic and pulmonary. The systemic circulation carries oxygenated blood from the heart to all the tissues in the body except the lungs and returns deoxygenated blood carrying waste products, such as carbon dioxide, back to the heart. The pulmonary circulation carries this spent blood from the heart to the lungs. In the lungs, the blood releases its carbon dioxide and absorbs oxygen. The oxygenated blood then returns to the heart before transferring to the systemic circulation.

44. Physical Activity With exercise, metabolism speeds up and because of this the muscles require more oxygen So the heart beats faster to supply the muscles with more oxygen-rich blood In turn the speed of blood flow increases. Blood Pressure Blood pressure is defined as the force exerted by the blood against the vessel wall. Blood pressure is highest in arteries and gradually decreases as it passes through arterioles, capillaries, venules and finally, veins. Blood pressure is also variable and can increase due to exercise where the cardiac output increases thus forcing more blood through the arteries or by altering the peripheral resistance. This occurs by vasoconstriction, increases in blood viscosity (thickness) and changes in shape or size of the vessels. The regulation of blood pressure is the responsibility of the sympathetic and parasympathetic nervous systems.

45. Blood Pressure • Blood against the blood vessel’s walls • The systolic pressure refers to • the pressure recorded while the ventricles pump the blood. • The diastolic pressure refers to • the pressure recorded as the ventricles fill with blood. • A normal blood pressure is 120/80

46. Digestive system via Circulatory system The circulatory system also transports nutrients derived from digested food to the body. Nutrients enter the bloodstream by passing through the walls of the intestine - absorbed through a network of capillaries and veins that drain the intestines, called the hepatic portal circulation. The hepatic portal circulation carries the nutrients to the liver for further metabolic processing. The liver also cleans the blood by removing waste products and toxins.

47. The circulatory system plays an important role in regulating body temperature. During exercise, working muscles generate heat. The blood supplying the muscles with oxygen and nutrients absorbs much of this heat and carries it away to other parts of the body. If the body gets too warm, blood vessels near the skin enlarge to disperse excess heat outward through the skin. In cold environments, these blood vessels constrict to retain heat. Blood vessels expand during exercise to meet the increased demand for blood and to cool the body. Blood vessels contract after an injury to reduce bleeding and also to conserve body heat.

48. Functions of the circulatory system: Distribute nutrients, Transport and exchange oxygen and carbon dioxide, Remove waste materials, Distribute secretions of endocrine glands,

49. Prevent excessive bleeding, Prevent infection, and Regulate body temperature.