1. The Heart and Circulatory System

2. Our circulation is a “double loop”. Our circulation is a “double loop”. Blood must pass through the heart twice in order to complete the circuit. Blood must pass through the heart twice in order to complete the circuit.

3. THE HEART The APEX of the heart is where the APICAL HEARTBEAT can be heart. It is in the 5 th intercostal space, about 4” (10 cm) to the left, midclavicular. The APEX of the heart is where the APICAL HEARTBEAT can be heart. It is in the 5 th intercostal space, about 4” (10 cm) to the left, midclavicular. The superior left corner is deep to costal cartilage #2, 1” to the left of midsternum. The superior left corner is deep to costal cartilage #2, 1” to the left of midsternum. The inferior right corner is 1” to the right of midsternal, deep to costal cartilage #6. The inferior right corner is 1” to the right of midsternal, deep to costal cartilage #6.

4. The final placement of the heart would require an axis placed: The final placement of the heart would require an axis placed: 1. Tilted to the left 2. Tilted anteriorly 3. Rotated so the anterior side is to the left.

5. Heart Chambers Anatomically, the heart has 4 chambers. Anatomically, the heart has 4 chambers. Functionally, the heart has 2 chambers or pump circuits. Functionally, the heart has 2 chambers or pump circuits.

7. The top chambers are ATRIA (singular- atrium). The top chambers are ATRIA (singular- atrium). The bottom chambers are VENTRICLES. The bottom chambers are VENTRICLES. The walls of the atrium are much thinner compared with the ventricles. The walls of the atrium are much thinner compared with the ventricles.

8. Topograhically, there is a small flap of tissue called the AURICLE. Topograhically, there is a small flap of tissue called the AURICLE. Connected to the chambers are large vessels: vena cavae, pulmonary arteries or trunk, pulmonary veins, and the aorta. Connected to the chambers are large vessels: vena cavae, pulmonary arteries or trunk, pulmonary veins, and the aorta.

9. 1. Right Auricle 2. Right Ventricle 3. Brachiocephalic Artery (Oxygenated) 4. Aortic Arch (Oxygenated) 5. Pulmonary Artery (Deoxygenated) 6. Left Auricle 7. Interventricular Sulcus 8. Left Ventricle Sheep Heart – Anterior View

10. 1. Brachiocephalic Artery (Oxygenated) 2. Aortic Arch (Oxygenated) 3. Openings for Pulmonary Veins (Oxygenated) 4. Opening for Inferior Vena Cava (Deoxygenated) 5. Left Ventricle 6. Opening for Superior Vena Cava (Deoxygenated) 7. Right Auricle 8. Right Ventricle

11. If we look at the heart from the anterior side, we the right side of the heart. If we look at the heart from the anterior side, we the right side of the heart. Blood returns to the heart (right atrium) via the SUPERIOR and INFERIOR VENA CAVAE and CORONARY SINUS. Blood returns to the heart (right atrium) via the SUPERIOR and INFERIOR VENA CAVAE and CORONARY SINUS.

12. From the right atrium it is pumped into the RIGHT VENTRICLE. From the right atrium it is pumped into the RIGHT VENTRICLE. It must pass through the TRICUSPID VALVE (which has 3 cusps) which is a ATRIOVENTRICULAR VALVE. It must pass through the TRICUSPID VALVE (which has 3 cusps) which is a ATRIOVENTRICULAR VALVE.

13. From the right ventricle, the blood then passes through the PULMONARY SEMILUNAR VALVE and into the PULMONARY TRUNK. From the right ventricle, the blood then passes through the PULMONARY SEMILUNAR VALVE and into the PULMONARY TRUNK. The pulmonary trunk carries blood to the lungs for re-oxygenation in the alveoli. The pulmonary trunk carries blood to the lungs for re-oxygenation in the alveoli.

14. All the valves are made of connective tissue and function to prevent backflow of blood. All the valves are made of connective tissue and function to prevent backflow of blood. Problems with the valves cause a disorder called PROLAPSE or MURMUR. Problems with the valves cause a disorder called PROLAPSE or MURMUR.

15. Blood returns to the LEFT ATRIUM via the PULMONARY VEINS. Blood returns to the LEFT ATRIUM via the PULMONARY VEINS. There are 2 pulmonary veins from each lung. There are 2 pulmonary veins from each lung. The blood next passes through the BISCUPID (2 cusps) or MITRAL VALVE on its way to the LEFT VENTRICLE. The blood next passes through the BISCUPID (2 cusps) or MITRAL VALVE on its way to the LEFT VENTRICLE.

16. From the left ventricle, blood passes through the AORTIC SEMILUNAR VALVE into the AORTA. From the left ventricle, blood passes through the AORTIC SEMILUNAR VALVE into the AORTA. To remember that the TRICUSPID VALVE comes before the BICUSPID VALVE, remember the saying: To remember that the TRICUSPID VALVE comes before the BICUSPID VALVE, remember the saying: “Try before you buy” “Try before you buy”

17. VALVES The valves open passively during ventricular relaxation. The valves open passively during ventricular relaxation. They close passively during ventricular contraction. They close passively during ventricular contraction. The CHORDAE TENDINEAE connect the edge of the AV valve to the PAPILLARY MUSCLE. The CHORDAE TENDINEAE connect the edge of the AV valve to the PAPILLARY MUSCLE.

18. Chordae tendinae

19. These muscles prevent the valves from being forced closed in reverse. These muscles prevent the valves from being forced closed in reverse. The chords contract when the papillary muscles pull on them. The chords contract when the papillary muscles pull on them. The papillary muscles DO NOT cause the valves to open or close. The papillary muscles DO NOT cause the valves to open or close.

20. The SEMILUNAR VALVES are found between the ventricles and the large arteries leaving the ventricles. The SEMILUNAR VALVES are found between the ventricles and the large arteries leaving the ventricles. They are TRICUSPID in structure. Heart sounds are caused by the closing of these valves. They are TRICUSPID in structure. Heart sounds are caused by the closing of these valves.

21. The Semilunar Valves 1 2 3

22. SUMMARY: SUMMARY: 4 chambers 4 valves 4 vessels ARTERIES=carry blood AWAY from the heart. VEINS = carry blood TOWARD the heart.

24. 1. Right CoronaryRight Coronary 2. Left Anterior DescendingLeft Anterior Descending 3. Left CircumflexLeft Circumflex 4. Superior Vena CavaSuperior Vena Cava 5. Inferior Vena CavaInferior Vena Cava 6. AortaAorta 7. Pulmonary ArteryPulmonary Artery 8. Pulmonary VeinPulmonary Vein 9. Right AtriumRight Atrium 10. Right VentricleRight Ventricle 11. Left AtriumLeft Atrium 12. Left VentricleLeft Ventricle 13. Papillary MusclesPapillary Muscles 14. Chordae TendineaeChordae Tendineae 15. Tricuspid ValveTricuspid Valve 16. Mitral ValveMitral Valve 17. Pulmonary ValvePulmonary Valve

25. CIRCULATION The importance of circulation is the movement of materials into and out of the cells. The importance of circulation is the movement of materials into and out of the cells. Cells require O2 and need to get rid of CO2. Cells require O2 and need to get rid of CO2. This is accomplished by two processes: BULK FLOW and DIFFUSION. This is accomplished by two processes: BULK FLOW and DIFFUSION.

26. Bulk Flow Bulk flow is the movement of blood over significant distances in a short period of time. Accomplished by pressure gradients. Bulk flow is the movement of blood over significant distances in a short period of time. Accomplished by pressure gradients. Blood moves from areas of high pressure to areas of low pressure. Blood moves from areas of high pressure to areas of low pressure.

27. We establish pressure gradients by using: We establish pressure gradients by using: 1. heart 1. heart 2. gravity 2. gravity 3. skeletal muscle 3. skeletal muscle 4. smooth muscle 4. smooth muscle

28. Diffusion Diffusion is the random movement of molecules with net movement from areas of high concentration to areas of low concentration. Diffusion is the random movement of molecules with net movement from areas of high concentration to areas of low concentration. It is only effective over short distances. It is only effective over short distances. It only happens in capillaries. It only happens in capillaries.

29. This can happen because capillaries are blood vessels that are only one cell thick. This can happen because capillaries are blood vessels that are only one cell thick. Capillaries are the FUNCTIONAL UNIT of circulation with the cells. Capillaries are the FUNCTIONAL UNIT of circulation with the cells.

30. The circulatory system is a CLOSED SYSTEM with three main components: The circulatory system is a CLOSED SYSTEM with three main components: 1. heart (bulk flow) 1. heart (bulk flow) 2. vessels (direct flow) 2. vessels (direct flow) 3. blood (used for transport) 3. blood (used for transport)

31. Path of Circulation Heart -> arteries -> arterioles -> capillaries -> venules -> veins -> heart

32. Arterioles are small arteries and have a lumen diameter of about 0.5 mm. Their anatomy is the same as arteries. Arterioles are small arteries and have a lumen diameter of about 0.5 mm. Their anatomy is the same as arteries.

33. Anatomy of an Artery Lumen Tunica Intima- inner lining – endothelia and CT Tunica Media – middle smooth muscular layer – thick in arteries, thin in veins Tunica Aventitia or Tunica Externa - contain CT and Vaso Vasorum Fibrous tissue layer

34. Recall that the arteries have a muscular pump to help blood get to the needed body parts. Recall that the arteries have a muscular pump to help blood get to the needed body parts. Veins do not have this pump. Veins do not have this pump. Skeletal muscle contractions help move the blood upward toward the heart. Also, veins have VALVES which prevent backflow of blood (gravity) Skeletal muscle contractions help move the blood upward toward the heart. Also, veins have VALVES which prevent backflow of blood (gravity)

35. When blood cannot travel back toward the heart, it can accumulate in the veins. This causes a dilation of the vein, or VARICOSE VEINS. When blood cannot travel back toward the heart, it can accumulate in the veins. This causes a dilation of the vein, or VARICOSE VEINS.

36. In Review VEINS ARTERIES VEINS ARTERIES 1. Toward heart CARRY BLOOD Away from heart 2. 2-3 cells thick MUSCULAR LAYER 40 cells thick 3. Semilunar Valves VALVES No valves 4. Decreased OXYGEN LEVELS Increased

38. Categories of Circulation 1. Pulmonary Circulation- Blood from right ventricle goes through the pulmonary trunk to lungs and back to left atrium. Blood from right ventricle goes through the pulmonary trunk to lungs and back to left atrium. There is much lower hydrostatic pressure than in the systemic circulation. There is much lower hydrostatic pressure than in the systemic circulation.

39. 2. Systemic Circulation 2. Systemic Circulation The second major circulatory loop. Blood leaves the left ventricle and is pumped throughout the body. It ends up in the right atrium. The second major circulatory loop. Blood leaves the left ventricle and is pumped throughout the body. It ends up in the right atrium. This loop includes blood supply to the GI tract to help with nutrient absroption. This loop includes blood supply to the GI tract to help with nutrient absroption.

40. Collateral Circulation Allows blood to flow around a blockage. Allows blood to flow around a blockage. Arterioles meet head on in an ANASTOMOSIS. Arterioles meet head on in an ANASTOMOSIS. Anastomoses serve as a natural bypass. Anastomoses serve as a natural bypass.

41. Portal Circulation Veins from pancreas, spleen, small intestine, and stomach empty into the portal vein in the liver. Veins from pancreas, spleen, small intestine, and stomach empty into the portal vein in the liver. After excess glucose is removed and detoxification occurs, blood enters the hepatic portal vein to be returned to the vena cava and the general circulation. After excess glucose is removed and detoxification occurs, blood enters the hepatic portal vein to be returned to the vena cava and the general circulation.

42. Fetal Circulation - needed because the fetal lung is not functional. Fetal oxygen source is the PLACENTA. - blood from mother and fetus do not mix, but rather is in 2 adjacent capillary beds. - blood from mother and fetus do not mix, but rather is in 2 adjacent capillary beds. - permeable materials can pass through the adjacent capillary beds causing the fetus to be exposed to whatever is in the mother’s bloodstream. - permeable materials can pass through the adjacent capillary beds causing the fetus to be exposed to whatever is in the mother’s bloodstream.

43. Blood flows from the placenta to the fetus via on UMBILICAL VEIN. - The UV has the most oxygen rich blood for the fetus. - The UV has the most oxygen rich blood for the fetus. - This vein branches with one part going to the FETAL LIVER and the other going to the INFERIOR VENA CAVAE (DUCTUS VENOSIS). - This vein branches with one part going to the FETAL LIVER and the other going to the INFERIOR VENA CAVAE (DUCTUS VENOSIS). - Blood then enters the right atrium. Blood so far is MIXED (both oxygenated and deoxygenated). - Blood then enters the right atrium. Blood so far is MIXED (both oxygenated and deoxygenated).

44. This blood is then combined with deoxygenated blood from the coronary sinus and superior vena cavae. This blood is then combined with deoxygenated blood from the coronary sinus and superior vena cavae. There is a hole (foramen) between the atria. This is called the FORAMEN OVALE. There is a hole (foramen) between the atria. This is called the FORAMEN OVALE. There is also a linkage between the pulmonary artery and the aorta. This is called the DUCTUS ARTERIOSUS. There is also a linkage between the pulmonary artery and the aorta. This is called the DUCTUS ARTERIOSUS.

45. The UMBILICAL ARTERIES branch from the INTERNAL ILIAC ARTERIES found in the pelvis. The ILA’s are branches of the COMMON ILIAC ARTERIES which are the terminal branches of the aorta. The UMBILICAL ARTERIES branch from the INTERNAL ILIAC ARTERIES found in the pelvis. The ILA’s are branches of the COMMON ILIAC ARTERIES which are the terminal branches of the aorta.

46. Coronary Circulation - heart has a separate circulation. - heart has a separate circulation. - these coronary vessels are the ones treated in “bypass” surgery. - these coronary vessels are the ones treated in “bypass” surgery. - CORONARY SULCUS or ATRIOVENTRICULAR GROOVE - CORONARY SULCUS or ATRIOVENTRICULAR GROOVE - INTERVENTRICULAR SULCUS. - INTERVENTRICULAR SULCUS. - The coronary arteries and veins are located within these grooves. - The coronary arteries and veins are located within these grooves.

47. Coronary Circulation

50. Each blood cell must pass through the heart twice in order to complete a full circulatory circuit. Each blood cell must pass through the heart twice in order to complete a full circulatory circuit.

51. Lymphatics (in general) The lymphatic system is a system that collects and recycles fluids that have leaked from the circulation. It is also involved in fighting infections. The lymphatic system is a system that collects and recycles fluids that have leaked from the circulation. It is also involved in fighting infections. It is made of a series of LYMPH VESSELS and tiny bean- shaped NODES. It is made of a series of LYMPH VESSELS and tiny bean- shaped NODES. Lymph tissue is located in various parts of the body including; thymus, tonsils, spleen, and bone marrow. Lymph tissue is located in various parts of the body including; thymus, tonsils, spleen, and bone marrow. The lymph tissue is eventually drained into the vena cava to go into the right atrium. The lymph tissue is eventually drained into the vena cava to go into the right atrium.

52. What is carried in the blood? Respiratory gasses (oxygen and CO2) Respiratory gasses (oxygen and CO2) Nutrients Nutrients Hormones Hormones Defense cells/Immune cells Defense cells/Immune cells Repair cells Repair cells It also regulates body temperature by carrying warmth from the center of the body to the periphery.

53. Blood Anatomy Blood is composed of two parts. Blood is composed of two parts. 1. FORMED ELEMENTS 1. FORMED ELEMENTS - cellular component - cellular component 2. PLASMA 2. PLASMA - liquid component - liquid component

54. Centrifuge Machine which spins tubes of blood to separate the components. Machine which spins tubes of blood to separate the components. RBC’s WBC’s BUFFY COAT Plasma

55. Plasma A straw-colored, sticky fluid. A straw-colored, sticky fluid. Contains over 100 different kinds of molecules. Contains over 100 different kinds of molecules. Contains three proteins: Contains three proteins: a. Albumin – important in keeping osmotic pressure constant. Also important in wound healing. a. Albumin – important in keeping osmotic pressure constant. Also important in wound healing. b. Globulins – important for antibody production and transport of other molecules. b. Globulins – important for antibody production and transport of other molecules. c. Fibrinogen – important for blood clotting c. Fibrinogen – important for blood clotting

56. Formed Elements These are the “blood cells” These are the “blood cells” 1. Erythrocytes a. RBC’s a. RBC’s b. Carry oxygen b. Carry oxygen c. No nuclei or organelles c. No nuclei or organelles d. % of blood volume that contain erythrocytes is known as the HEMATOCRIT. d. % of blood volume that contain erythrocytes is known as the HEMATOCRIT.

57. e. cytoplasm is filled with HEMOGLOBIN. e. cytoplasm is filled with HEMOGLOBIN. f. Hemoglobin is the oxygen carrying protein. f. Hemoglobin is the oxygen carrying protein. g. Pick up oxygen in the lung capillaries and release carbon dioxide. g. Pick up oxygen in the lung capillaries and release carbon dioxide. h. Spherical shaped h. Spherical shaped i. When the shaped changes, individual cells have difficulty entering and traveling through the capillary lumen. i. When the shaped changes, individual cells have difficulty entering and traveling through the capillary lumen. j. Efficient oxygen transporters as they do not use any of the oxygen they transport. This is because they do not have organelles (mitochondria). The erythrocytes must get their energy through anaerobic means. j. Efficient oxygen transporters as they do not use any of the oxygen they transport. This is because they do not have organelles (mitochondria). The erythrocytes must get their energy through anaerobic means.

58. k. Live for 120 days. Therefore, it is easy to use them for clinical testing. For example, glucose binds to the RBC. The more glucose that is bound to the RBC, the higher the patients average blood sugar levels. HbA1C is a measurement of how much sugar is bound to the RBC. If this test is performed every 120 days, physicians can determine the range of blood sugar control. k. Live for 120 days. Therefore, it is easy to use them for clinical testing. For example, glucose binds to the RBC. The more glucose that is bound to the RBC, the higher the patients average blood sugar levels. HbA1C is a measurement of how much sugar is bound to the RBC. If this test is performed every 120 days, physicians can determine the range of blood sugar control.

59. LEUKOCYTES White Blood Cells (WBC) White Blood Cells (WBC) Crucial to the bodies defense against disease. Crucial to the bodies defense against disease. Have all the organelles and nuclei of a true cell. Have all the organelles and nuclei of a true cell. Leukocytes perform their function outside the circulatory system. They function in the connective tissue (where infections usually occur). Leukocytes perform their function outside the circulatory system. They function in the connective tissue (where infections usually occur). When a leukocyte senses an infection, it moves out of the circulation by squeezing out between the endothelial cells which line the blood vessels. This is known as DIAPEDESIS. When a leukocyte senses an infection, it moves out of the circulation by squeezing out between the endothelial cells which line the blood vessels. This is known as DIAPEDESIS. Once outside the circulation, the WBC’s use amoeboid motion to find the offending organism. Once outside the circulation, the WBC’s use amoeboid motion to find the offending organism.

60. 5 Types of Leukocytes Granulocytes 1. Neutrophils – most abundant 1. Neutrophils – most abundant - lobuated nuclei - lobuated nuclei - “Polymorphonuclear - “Polymorphonuclear Leukocytes” (PMN’s) Leukocytes” (PMN’s) - “Polys” or “Segs” - “Polys” or “Segs” - phagocytize and - phagocytize and destroy bacteria. destroy bacteria.

61. 2. Eosinophils - rarely found - rarely found - nuclei with only 2 lobes - nuclei with only 2 lobes - stain red with acidic dye “Eosin” - stain red with acidic dye “Eosin” - fight parasites and parasitic diseases - fight parasites and parasitic diseases

62. 3. Basophils - rarest of all WBC’s - rarest of all WBC’s - nuclei stain dark with basic stain - nuclei stain dark with basic stain - secrete histamine to mediate allergic reactions. - secrete histamine to mediate allergic reactions.

63. Agranulocytes Agranulocytes 1. Lymphocytes 1. Lymphocytes - most important cell in the immune system - most important cell in the immune system - function in the connective tissue, not the bloodstream - function in the connective tissue, not the bloodstream - important for fighting infection - important for fighting infection - substances that cause a reaction from a lymphocyte is called an ANTIGEN. - substances that cause a reaction from a lymphocyte is called an ANTIGEN. - 2 types of lymphocytes: T-cells (kill organisms directly) - 2 types of lymphocytes: T-cells (kill organisms directly) B-cells (become mast cells B-cells (become mast cells

64. 2. Monocytes - become macrophages which ingest a wide variety of foreign debris - become macrophages which ingest a wide variety of foreign debris

65. CLINICAL CORELLATION A complete blood count (CBC) - Quantifies the various cell types found in the blood. - A DIFFERENTIAL identifies the percentage of each type of leukocyte.

66. Platelets Known as THROMBOCYTES Known as THROMBOCYTES Function to plug small tears in the walls of the blood vessels to limit bleeding. Function to plug small tears in the walls of the blood vessels to limit bleeding. Adhere to exposed collagen at the edges of a tear. Adhere to exposed collagen at the edges of a tear. Release THROMBOPLASTIN, a molecule that initates clotting. Release THROMBOPLASTIN, a molecule that initates clotting. Platelets adhere only to damaged blood vessels. When a clot develops or persists in an intact blood vessel, a THROMBUS results. Platelets adhere only to damaged blood vessels. When a clot develops or persists in an intact blood vessel, a THROMBUS results.