1. The Cardiovascular System

2. Structure of the heart Pericardium – encloses heart. Visceral pericardium – inner layer; parietal – outer layer. Wall of heart – 3 layers: 1 Epicardium – protects heart (reduces friction) – visceral pericardium.

3. http://www.texasheartinstitute.org/HIC/Topics/images/myocard.jpg

4. 2 Myocardium – cardiac muscle; thick middle layer. 3 Endocardium – contains blood vessels – inner lining of blood vessels.

5. http://sprojects.mmi.mcgill.ca/embryology/cvs/graphics/tube_trans.gif

6. Heart divided into 4 chambers. 2 atria – upper chambers, thin- walled; receive blood returning to heart. 2 ventricles – lower chambers, thicker walled; pump blood into arteries.

7. http://web.buddyproject.org/web019/web019/images/Heart2.jpg

8. Septum divides atrium and ventricle on right from left side. R atrium receives blood from body from inferior vena cava and superior vena cava. R atrium separated from R ventricle by tricuspid valve.

9. http://www.integrativebiology.ac.uk/images/heart.jpg

10. Developing fetus - hole between L and R atria. After birth - hole supposed to close. If hole does not close - hole in heart (atrial septal defect) Blood enters lungs - breathing problems.

11. http://texasheart.org/HIC/Topics/images/asd.jpg

12. Chordae tendineae – attach cusps of tricuspid valve. Originate from papillary muscles on walls of ventricles. R ventricle pumps blood through pulmonary artery to lungs. Pulmonary valve leads into artery.

13. http://www.delftoutlook.tudelft.nl/info/images/100703033722010.jpg

14. * L atrium receives blood from lungs through pulmonary vein. L atrium and L ventricle separated by bicuspid (mitral) valve. L ventricle pumps through aorta to entire body. Aortic valve leads into aorta.

15. http://www.med.yale.edu/intmed/cardio/echo_atlas/entities/graphics/bicuspid_aortic_valve.gif http://www.lifeisnow.com/Images/Sections/MyHeart/03_ViewOfTheHeartValves.jpg

16. Mitral valve prolapse – one or both cusps stretch and bulge into L atrium during contraction. Results in blood going back into L atrium.

18. Blood flow Blood low in O 2, high in CO 2 enters R atrium. R atrium passes blood into R Ventricle. R ventricle contracts, blood flows into pulmonary artery (to lungs) Pulmonary vein brings blood high in O 2 back to L atrium.

19. http://www.shoppingtrolley.net/images/anatomy/heart.gif

20. Blood passes to L ventricle. Pumped through aorta to body. 1 st 2 branches of aorta – R,L coronary arteries – supply blood to heart tissue. Cardiac veins – drain blood, join together to form coronary sinus – dump into R atrium.

21. http://www.nlm.nih.gov/medlineplus/ency/imagepages/18128.htm

22. Cardiac cycle Heart sounds made from opening and closing of valves. 1 st sound made from recoil of blood against closed AV valves (“lub”) 2 nd sound made from recoil of blood against semilunar valves. (“dup”) Heart murmurs result of incomplete valve closure resulting in swishing noise.

23. http://www.nlm.nih.gov/medlineplus/ency/imagepages/19613.htm

24. Sinoatrial node (SA node) – generates action potentials on its own (pacemaker). Impulse passes along fibers to mass of specialized tissue (atrioventricular node)

25. http://dtc.pima.edu/~biology/202alpha/lesson2/conductionsystem.jpg

26. From AV node, moves through bundle of His (AV bundle) Divide into L and R branches underneath endocardium. Give rise to Purkinje fibers. Causes ventricular walls to contract.

27. http://www.nlm.nih.gov/medlineplus/ency/imagepages/18052.htm

28. ECG Electrocardiogram – recording of electrical changes in heart muscle. QRS complex – depolarization of ventricular fibers (ventricles contract) T wave – ventricular fibers repolarize.

29. http://www.nlm.nih.gov/medlineplus/ency/imagepages/1135.htm

30. Heart rate – duration of cardiac cycle. Stroke volume – volume of blood ejected from ventricles during contraction. Cardiac output = heart rate X stroke volume.

31. http://www.pathguy.com/pathphys/pathphy4.gif

32. More cells stretched by incoming blood, more strongly heart walls contract to eject blood – Starling’s law of the heart. Cardiac output increases with increasing exercise and blood flow.

33. http://www.besthealth.com/besthealth/bodyguide/reftext/images/100085.jpg

34. Heart rate monitored in medulla oblongata of brain. Increase in blood pressure – stretch sensors send message to brain to slow heart rate down.

35. http://www.gnosticteachings.org/images/stories/energies/medulla_oblongata.jpg

36. Blood vessels Arteries – carry oxygenated blood away from heart. Branch into arterioles, then capillaries. Artery – 3-layered wall surrounding interior (lumen).

37. http://www.web-books.com/eLibrary/Medicine/Cardiovascular/Images/Athero.gif

38. 1 Tunica intima – innermost layer. 2 Tunica media – thick smooth muscle layer (middle) 3 Tunica adventitia – outer layer; anchors artery to neighboring structures.

39. http://www.nlm.nih.gov/medlineplus/ency/imagepages/19194.htm

40. Vasoconstriction – vessel decreases in diameter. Vasodilation – vessel increases in diameter. Pulmonary artery – carries deoxygenated blood away from heart (toward lungs)

41. http://www.nlm.nih.gov/medlineplus/ency/imagepages/8983.htm

42. Capillaries – smallest vessels. Permit exchange of nutrients, removal of wastes at tissue level. Thin, permeable walls to allow diffusion to occur.

43. http://www-rocq.inria.fr/who/Marc.Thiriet/Glosr/Bio/AppCircul/ImagCircul/MicroCirc.gif

44. Veins – carry deoxygenated blood back to heart. Capillaries join venules, join to form veins. Same 3 layers; tunica media not very thick.

45. http://www.merck.com/media/mmhe2/figures/fg036_3.gif

46. Blood pressure in veins not high, so veins need valves to prevent backflow. Blood must flow against gravity back to heart.

47. http://www.vascularweb.org/graphics/northpoint_graphics_jpg/Varicose_02_Base_300.jpg

48. Blood Pressure Blood pressure – force exerted by blood against walls of vessels. Systolic pressure – stretch of arteries to allow for blood flow pumped from heart. Diastolic pressure – relaxation.

49. http://www.ghi.com/WebMD/topics/bloodpressure.jpg

50. Pulse – expanding, recoiling of arterial walls. Represents # of heartbeats per minute.

51. http://www.nlm.nih.gov/medlineplus/ency/imagepages/9801.htm

52. Factors affecting blood pressure 1 Cardiac output – increase in cardiac output increases blood pressure. 2 Peripheral resistance – friction + drag in vessels; increases blood pressure. Vasoconstriction increases b.p.

53. http://www-rohan.sdsu.edu/course/ens304/public_html/section1/Image34.gif

54. 3 Blood volume – decrease causes drop in b.p. Sympathetic nervous system – causes rise in b.p, heart rate. Parasympathetic – decrease.

55. http://www.biocomtech.com/upload/images/hrs_ce_002pic03.jpg

56. Hormones regulate b.p. Epinephrine, norephinephrine – rise, fall of b.p. Antidiuretic hormone – rise in b.p. Kidneys aid in regulation – drop in b.p. releases renin; renin causes formation of angiotensin.

57. Angiotensin – vasoconstriction. Stimulates release of aldosterone – increases b.p.

58. http://www.colorado.edu/kines/Class/IPHY3430-200/image/angiotensin.jpg

59. Circulatory Pathways 1 Pulmonary circulation – pulmonary trunk carries blood from R ventricle. Divides into R and L pulmonary artery, into capillaries. O 2 picked up in lungs, brought back to heart via pulmonary veins.

60. http://webschoolsolutions.com/patts/systems/pul-circ.gif

61. Arteries 2 Systemic – blood leaves L ventricle into ascending aorta. Branches into R, L coronary arteries (supply heart wall). Aorta curves to back (aortic arch) 3 branches – brachiocephalic, L common carotid, L subclavian.

62. http://butler.cc.tut.fi/~malmivuo/bem/bembook/06/fi/0602.gif

63. Aorta turns downward (descending aorta). Section above diaphragm – thoracic aorta; branch into intercostal arteries (supply thoracic wall). Below diaphragm – abdominal aorta.

64. http://healthlink.uhseast.com/library/healthguide/en-us/images/media/medical/hw/nr551517.jpg

65. Branches into celiac artery (liver, spleen, stomach, pancreas), superior mesenteric artery (small intestine), suprarenal arteries (adrenal glands), renal arteries (kidneys), inferior mesenteric artery (large intestine). Divides into R, L iliac (to lower legs)

66. http://www.merck.com/media/mmhe2/figures/fg034_1.gif

67. Pelvis, lower limbs – common iliac divides into internal, external iliac. External iliac – becomes femoral. Forms deep femoral artery (flexor muscles of thigh), popliteal artery (knee), anterior, posterior tibial arteries.

68. Head, neck – from common carotid, subclavian. R common carotid arises from brachiocephalic. R, L common carotid branch into external, internal carotid.

69. http://www.nlm.nih.gov/medlineplus/ency/imagepages/9552.htm

70. Shoulder, upper limbs – from subclavian. Axillary artery – near armpit. Continues down arm as brachial artery; divides into ulnar, radial arteries.

71. http://www.eorthopod.com/images/ContentImages/elbow/elbow_anatomy/elbow_anatomy09a.jpg

72. Veins Head, face veins – blood drained into R, L external jugular. Merge with subclavian veins  internal jugular  brachiocephalic vein  superior vena cava.

73. http://www.anaesthesiauk.com/images/frca_img_ijv.gif

74. Upper limbs – ulnar, radial vein  brachial vein  axillary vein. Major superficial arm veins – basilic (forearm to middle of upper arm), cephalic (wrist to shoulder), median cubital vein (where blood is drawn).

75. http://www.dartmouth.edu/~anatomy/assets/self-tests/elbow/surface/surf-ant-elbow-st.jpg

76. Inferior vena cava – longest vein in body – great saphenous vein, joins with femoral vein. Abdomen – hepatic portal system – blood from capillaries of digestive tract to liver only. Dumps blood into superior, inferior mesenteric veins.

77. http://www.nlm.nih.gov/medlineplus/ency/imagepages/8733.htm

78. Diseases 1 Congestive heart failure – can’t pump blood to body. Bad circulation to body  increased pressure, fluid leaking in lungs. Caused by damage to cardiac muscle. Symptoms – shortness of breath, swelling in lower legs.

79. http://www.valley-homecare.com/resource/images/chf_hearts.gif

80. 2 Hypertension – increase in blood pressure. Due to narrowing of blood vessels (atherosclerosis) or hardening of vessels (arteriosclerosis)

81. http://www.nlm.nih.gov/medlineplus/ency/imagepages/18077.htm

82. 3 Endocarditis – infection of lining of heart due to bacterial infection. Can cause embolus (blood clot) 4 Aneurysm – sac formation in vessel or heart chamber; can produce tear in vessel (hemorrhage)

83. http://www.nlm.nih.gov/medlineplus/ency/imagepages/17031.htm