1 The Cardiovascular System11 The Cardiovascular System

2 The Cardiovascular SystemHeart AND Blood Vessels are the Organs with the Connective Tissue-Blood as the fluid being moved

3 I. The Heart A. Introduction Location: Chambers Base Apex Size =Main Tissue Type:

4 Midsternal line 2nd rib Sternum Diaphragm (a)Point of maximal intensity (PMI) (a) Figure 11.1a

5 Aorta Left lung Diaphragm (c)Superior vena cava Aorta Parietal pleura (cut) Pulmonary trunk Left lung Pericardium (cut) Apex of heart Diaphragm (c) Figure 11.1c

6 Mediastinum Heart Left lung Posterior (b)Figure 11.1b

7 Brachiocephalic trunk Left common carotid arterySuperior vena cava Left subclavian artery Right pulmonary artery Aortic arch Ligamentum arteriosum Ascending aorta Left pulmonary artery Pulmonary trunk Left pulmonary veins Right pulmonary veins Left atrium Auricle of left atrium Right atrium Circumflex artery Right coronary artery in coronary sulcus (right atrioventricular groove) Left coronary artery in coronary sulcus (left atrioventricular groove) Anterior cardiac vein Left ventricle Right ventricle Great cardiac vein Marginal artery Anterior interventricular artery (in anterior interventricular sulcus) Small cardiac vein Inferior vena cava Apex (a) Figure 11.3a

8 B. Anatomy 1. Heart Coverings = Pericardium—a double-walled sacFibrous pericardium: Serous membrane: Visceral pericardium = epicardium of heart Parietal pericardium Serous fluid:

9 2. The Heart: Heart Wall Epicardium Tissue Myocardium EndocardiumEndothelium Pulmonary trunk Fibrous pericardium Pericardium Pericardial cavity Myocardium Epicardium (visceral layer of serous pericardium) Heart wall Myocardium Endocardium Heart chamber

10 3. Chambers 2 separate pumps Four chambers Atria VentriclesRight Side of Heart: Left Side of Heart: Four chambers Atria Structure Receive blood from: Right A. Left A. Ventricles Pump blood: Right V. Left V.

11 Left ventricle Right ventricle Muscular interventricular septumFigure 11.5

12 4. The Heart: Septa Interventricular septum Separates:Interatrial septum

13 5. The Heart’s Role in Blood Circulationa) General Path of Blood Into heart to __________________ Atria  _______________ of same side Ventricle  ________________

14 The Heart’s Role in Blood Circulationb) Two Circulations Systemic circulation: left side of the heart  Pulmonary circulation: right side of the heart  Blood in both circulations move continuously

15 Figure 11.4 Capillary beds of lungs where gas exchange occursPulmonary Circuit Pulmonary arteries Pulmonary veins Venae cavae Aorta and branches Left atrium Left ventricle Right atrium Heart Right ventricle Systemic Circuit Capillary beds of all body tissues where gas exchange occurs KEY: Oxygen-rich, CO2-poor blood Oxygen-poor, CO2-rich blood Figure 11.4

16 6. The Heart: Valves Function: Two types of valves– total of 4 valvesa) Atrioventricular (AV) valves Parts: cusps & Chordae Tendineae Specific Valves: Bicuspid (mitral) Tricuspid

17 b) Semilunar valves—between ____ and ____Pulmonary semilunar Aortic semilunar

18 Right pulmonary artery Left atriumSuperior vena cava Aorta Left pulmonary artery Right pulmonary artery Left atrium Right atrium Left pulmonary veins Right pulmonary veins Pulmonary semilunar valve Left atrioventricular valve (bicuspid valve) Fossa ovalis Aortic semilunar valve Right atrioventricular valve (tricuspid valve) Left ventricle Right ventricle Chordae tendineae Interventricular septum Inferior vena cava Myocardium Visceral pericardium (b) Frontal section showing interior chambers and valves. Figure 11.3b

19 c) When valves are open and closed:Heart Valves … c) When valves are open and closed: Heart is filling with blood: AV valves: Semilunar valves: Heart Pumping = Ventricles contract: Valves operate opposite of one another

20 7. Associated Great VesselsPulmonary Trunk a) Arteries Aorta Blood leaves ____________ Pulmonary arteries Blood leave _______________ Pulmonary Trunk  L and R Pulmonary A.

21 Associated Great Vessels …b) Veins Superior Vena Cava Blood returns from: and goes to: Inferior Venae Cava And goes to: Pulmonary veins (four)

22 Brachiocephalic trunk Left common carotid arterySuperior vena cava Left subclavian artery Right pulmonary artery Aortic arch Ligamentum arteriosum Ascending aorta Left pulmonary artery Pulmonary trunk Left pulmonary veins Right pulmonary veins Left atrium Auricle of left atrium Right atrium Circumflex artery Right coronary artery in coronary sulcus (right atrioventricular groove) Left coronary artery in coronary sulcus (left atrioventricular groove) Anterior cardiac vein Left ventricle Right ventricle Great cardiac vein Marginal artery Anterior interventricular artery (in anterior interventricular sulcus) Small cardiac vein Inferior vena cava Apex (a) Figure 11.3a

23 C. Heart Physiology 1. Cardiac CirculationMyocardium nourished by: Coronary arteries: Cardiac veins: Coronary sinus: From Coronary Sinus, blood empties:

24 Blood Flow Through the HeartSuperior & Inferior Vena Cava  RA RA  tricuspid valve  RV RV  pulmonary semilunar valve  Pulmonary Trunk Pulmonary Trunk  Right and Left Pulmonary Arteries  Lungs AORTA SV PA PV LA RA RV LV IV

25 Lungs  Pulmonary veins  LALA  Bicuspid Valve  LV LV  Aortic Semilunar Valve  Aorta Aorta  body cells AORTA SV PA PV LA RA LV RV IV

26 Figure 11.4 Capillary beds of lungs where gas exchange occursPulmonary Circuit Pulmonary arteries Pulmonary veins Venae cavae Aorta and branches Left atrium Left ventricle Right atrium Heart Right ventricle Systemic Circuit Capillary beds of all body tissues where gas exchange occurs KEY: Oxygen-rich, CO2-poor blood Oxygen-poor, CO2-rich blood Figure 11.4

27 AORTA SV PA PV LA RA LV RV IV

28 C. Heart Physiology … 2. The Heart: Conduction System= autorhythmic cardiac cells + special conductive tissue a) Autorhythmic cells

29 The Heart: Conduction System …b) Special tissue Sinoatrial node = SA node (“pacemaker) Function Atrioventricular node = AV node,

30 Atrioventricular bundle = AV bundle Function Bundle branchesConduction System … Atrioventricular bundle = AV bundle Function Bundle branches Purkinje fibers

31 Superior vena cava Sinoatrial (SA) node (pacemaker) Left atriumAtrioventricular (AV) node Right atrium Atrioventricular (AV) bundle (bundle of His) Bundle branches Purkinje fibers Purkinje fibers Interventricular septum Figure 11.7

32 c) EKG & Heart Contraction DisordersNormal EKG P QRS T MilliVolts P QRS T Time Electrocardiogram

33 Abnormal Rhythums Heart Block SA node dysfunction Fibrillation Cardiac Arrest Tachycardia— Bradycardia—

34 3. The Heart: Cardiac Cycle & Heart SoundsCardiac cycle = events of one complete heart beat BASICS Atria contract simultaneously Atria relax, then ventricles contract Systole = contraction Diastole = relaxation

35 4. The Heart: Cardiac OutputStroke volume (SV) = Volume of blood pumped by a ventricle in one contraction = 70 mL

36 Heart rate (HR) = beats per minute: 75 Cardiac output (CO) Amount of blood pumped by each ventricle per minute CO = 70ml x 75 beats/min = ml/min

37 5. The Heart: Regulation of Heart RateAutonomic Nervous System & Endocrine System Increases in Heart Rate Sympathetic NS Hormones Epinephrine Thyroxine Raise HR when: Decreased blood volume or pressure

38 The Heart: Regulation of Heart Rate … Decrease Heart RateParasympathetic Nervous System

39 II. Blood Vessels: The Vascular SystemIntroduction: General Functions and Anatomy: 1. General Function Arteries Arterioles Veins Venules Capillaries

40 2. Blood Vessel StructureArtery Pressure Wall Vein Valves

41 Valve (open) Valve (closed) VeinContracted skeletal muscle Valve (closed) Vein Direction of blood flow Figure 11.11

42 Blood Vessel Structure …Cappillaries Thickness Cap. Bed Exchange of substances Precapillary Sphincters

43 B. Major Arteries of System CirculationAorta Largest artery in the body Leaves heart from __ Regions Ascending aorta Aortic arch

44 Major Arteries of System CirculationThoracic aorta: travels through thorax Abdominal aorta: through diaphragm into abdominopelvic cavity Arterial branches Right and left coronary arteries

45 Brachiocephalic trunk Left common carotid arterySuperior vena cava Left subclavian artery Right pulmonary artery Aortic arch Ligamentum arteriosum Ascending aorta Left pulmonary artery Pulmonary trunk Left pulmonary veins Right pulmonary veins Left atrium Auricle of left atrium Right atrium Circumflex artery Right coronary artery in coronary sulcus (right atrioventricular groove) Left coronary artery in coronary sulcus (left atrioventricular groove) Anterior cardiac vein Left ventricle Right ventricle Great cardiac vein Marginal artery Anterior interventricular artery (in anterior interventricular sulcus) Small cardiac vein Inferior vena cava Apex (a) Figure 11.3a

46 Major Arteries of Systemic CirculationArterial branches … Right and Left common carotid artery splits into Left internal and external carotid arteries

49 C. Major Veins of Systemic CirculationSuperior & inferior vena cava enter the ____ Superior vena cava drains the head and arms Inferior vena cava drains the lower body

50 Right pulmonary artery Left atriumSuperior vena cava Aorta Left pulmonary artery Right pulmonary artery Left atrium Right atrium Left pulmonary veins Right pulmonary veins Pulmonary semilunar valve Left atrioventricular valve (bicuspid valve) Fossa ovalis Aortic semilunar valve Right atrioventricular valve (tricuspid valve) Left ventricle Right ventricle Chordae tendineae Interventricular septum Inferior vena cava Myocardium Visceral pericardium (b) Frontal section showing interior chambers and valves. Figure 11.3b

51 Major Veins of Systemic CirculationVeins draining into the superior vena cava Internal jugular veins:

53 Figure 11.14 Veins of the head and trunk Dural venous sinusesExternal jugular vein Vertebral vein Internal jugular vein Veins that drain the upper limb Subclavian vein Right and left brachiocephalic veins Axillary vein Superior vena cava Cephalic vein Brachial vein Great cardiac vein Basilic vein Hepatic veins Splenic vein Hepatic portal vein Renal vein Median cubital vein Superior mesenteric vein Ulnar vein Radial vein Inferior mesenteric vein Digital veins Veins that drain the lower limb External iliac vein Inferior vena cava Femoral vein Common iliac vein Great saphenous vein Popliteal vein Internal iliac vein Posterior tibial vein Anterior tibial vein Small saphenous vein Dorsal venous arch Dorsal metatarsal veins Figure 11.14

54 D. Fetal Circulation Blood flow bypasses the lungs & Left Heart Why?How: Foramen Ovale: Fossa Ovalis:

55 2) Ductus arteriosus: ligamentum arteriosum

56 Fetal Circulation Fetal Nutrition: placenta Umbilical cord:Umbilical arteries (2)—carry carbon dioxide and wastes Branch from: Umbilical vein—carries nutrients and oxygen Drain into:

57 Superior vena cava Ductus arteriosus Pulmonary artery Pulmonary veins Foramen ovale Inferior vena cava Hepatic vein Ductus venosus Inferior vena cava Hepatic portal vein Umbilical vein Fetal umbilicus Aorta Common iliac artery Umbilical cord External iliac artery Internal iliac artery Umbilical arteries Urinary bladder KEY: High oxygenation Moderate oxygenation Low oxygenation Very low oxygenation Placenta Figure 11.16

58 E. Physiology of Blood vessels 1. PulsePulse= Pressure wave of blood Monitored at “pressure points” in arteries Wrist Upper neck Pulse averages 70 to 76 beats per minute at rest

60 2. Blood Pressure: BP = Measured in mmHg Systolic— Diastolic—Sphygmomanometer:

61 Blood pressure 120 systolic 70 diastolic (to be measured) Brachialartery (a) The course of the brachial artery of the arm. Assume a blood pressure of 120/70 in a young, healthy person. Figure 11.21a

62 Pressure in cuff above 120; no sounds audible 120 mm Hg Rubber cuff inflated with air Brachial artery closed (b) The blood pressure cuff is wrapped snugly around the arm just above the elbow and inflated until the cuff pressure exceeds the systolic blood pressure. At this point, blood flow into the arm is stopped, and a brachial pulse cannot be felt or heard. Figure 11.21b

63 Pressure in cuff below 120, but above 70 120 mm Hg 70 mm Hg Sounds audible in stethoscope (c) The pressure in the cuff is gradually reduced while the examiner listens (auscultates) for sounds in the brachial artery with a stethoscope. The pressure read as the first soft tapping sounds are heard (the first point at which a small amount of blood is spurting through the constricted artery) is recorded as the systolic pressure. Figure 11.21c

64 Pressure in cuff below 70; no sounds audible 70 mm Hg (d) As the pressure is reduced still further, the sounds become louder and more distinct; when the artery is no longer constricted and blood flows freely, the sounds can no longer be heard. The pressure at which the sounds disappear is recorded as the diastolic pressure. Figure 11.20d

65 Factors that affect BP:Cardiac Output: If increased, BP __________ Water content Heart rate Peripheral Resistance = friction blood encounters as it flows through vessels Diameter of the blood vessels Constricted Dialated

66 Contral: Circulatory and Excretory SystemsRenal factors Renin—hormonal control for blood volume

67 Blood Pressure: Effects of FactorsAge Weight Exercise Body position Emotional state Sympathetic and Parasympathetic NS Temperature Heat: vasodilate Cold: vasoconstrict

68 Abnormal Blood PressuresHypotension Low systolic: below 110 mm Hg Hypertension High systolic: above 140 mm Hg

69 F. Diseases of the Cardiovascular SystemAtherosclerosis STUDENTS DO

70 END