1. Warm-Up What is the pacemaker? Where is it located?
List the parts of the intrinsic conduction system of the heart.
Draw and label the 3 waves of a typical EKG tracing. What is happening at each wave?
What causes the heart sounds (lub-dub)?

2. Warm-Up Compare arteries, capillaries, & veins.
Imagine you are a red blood cell. List the pathway you would travel through the body in a complete circuit starting at a pinky toe.
Explain how blood pressure is measured.

3. Warm-Up What is hypertension? What are possible causes?
What is atherosclerosis?
What can you do to prevent atherosclerosis?
What treatment options are available for patients with coronary atherosclerosis?

4. Warm-Up
Draw the human heart and the main blood vessels in/out of the heart.
Label the following on your diagram:
4 chambers
4 valves
All blood vessels going into/out of heart
Using a blue pencil, indicate oxygen-poor blood flow
Using a red pencil, indicate oxygen-rich blood flow

5. Chapter 13 - Cardiovascular System

6. Major Functions Transport O2 and nutrients to tissues
Remove wastes from tissues

8. Anatomy and Location of Heart
Size of fist
Weight < 1 lb.
Within mediastinum of thoracic cavity
Apex points toward left hip
Flanked by lungs
Surrounded by pericardium (double-walled sac)

10. Pericardium – encloses the heart
3 layers
Fibrous pericardium - outer layer; attached to diaphragm
Visceral pericardium - inner layer; covers heart
Parietal pericardium - inner lining of the fibrous pericardium
Pericardial Cavity
Space between parietal and visceral pericardium filled with serous fluid to reduce friction during heart contractions
Pericarditis – inflammation of pericardium

11. Pericarditis

12. Layers of the Heart Wall
Epicardium – outer layer (pericardium)
Myocardium – cardiac muscle
Endocardium – endothelium lines chambers
Heart chamber

13. Heart Chambers Right Side Left Side
Atrium (R & L): receive blood (entryway)
Ventricle (R & L): pump blood out
Septum: wall between atria & ventricles
Valves: prevent backflow of blood

14. Atria Upper chambers Thin walls Left atrium
Receives blood returning from the lungs via pulmonary veins
Right atrium
Receives blood from superior and inferior vena cava and the coronary sinus
Auricles on top of atria
Help atria receive more blood

15. Ventricles Lower chambers Thick-muscled to pump blood to body
Contains:
Papillary muscles
Contract when the ventricle contracts; attached to Chordae tendinae
Chordae tendinae
Attach to valves to keep them from swinging back into the atria

16. Right Ventricle Left Ventricle Pulmonary circuit = low pressure
Systemic circuit = high resistance to blood flow
More powerful pump
3x as thick as right ventricle

17. Heart Valves Prevent back flow of blood Atrioventricular (A-V) valves:
Tricuspid valve
Between right atria and right ventricle
Bicuspid (mitral) valve
Between left atria and left ventricle
Pulmonary semilunar valve
Between right ventricle and pulmonary artery
Aortic semilunar valve
Between the left ventricle and aorta

19. Mitral Valve Prolapse Affects up to 6% of the population
Bicuspid valves stretch and bulge into the left atrium
Susceptible to endocarditis
Bacterial infection
Prevent with antibiotics
Symptoms
Chest pain, palpitations, fatigue, anxiety

20. Endocarditis

21. Double Circulation Loop
Pulmonary circuit: blood to/from lungs
Systemic circuit: blood to/from all body tissues

23. Pathway of Blood Through Heart

25. Pathway of Blood
Vena cava/coronary sinus  Right atrium  Tricuspid  Right ventricle  Pulmonary semilunar valve  Pulmonary arteries (deoxygenated blood)  Lungs  Pulmonary veins (oxygenated blood)  Left atrium  Bicuspid  Left ventricle  Aortic semilunar valve  Aorta  Body organs, tissues, and cells

26. Coronary Vessels First 2 branches of the aorta
Supply heart tissue with blood
Myocardium
Contains MANY capillaries
Drained by coronary veins
Veins empty into coronary sinus
Returns the blood to the right atria

29. Cardiac Cycle Series of events that constitute a heartbeat
Pressure within the heart chambers rises and falls with the contraction and relaxation of atria and ventricles
70% - flows naturally
30% - needs to be pumped
0.8 seconds for one cycle to be completed

30. Heart Sounds “Lub”: closing of AV valves
“Dub”: semilunar valves close at end of systole
Murmur – abnormal sounds that indicate valve problem

31. Heart Rhythm
Cardiac muscle cells can contract spontaneously and independently
Regulation of heart activity:
Autonomic nervous system
Epinephrine, thyroxine:  heart rate
Low Ca2+ levels:  heart rate
Intrinsic conduction system
Built into heart tissue & sets basic rhythm
Pacemaker = Sinoatrial (SA) Node

32. Intrinsic conduction system
Sequence of action:
Sinoatrial (SA) node – right atrium
Generates impulses  Starts each heartbeat
Atrioventricular (AV) node – between atria & ventricles
Atria contract
Bundle of His (or AV bundle)
Bundle branches – interventricular septum
Purkinje fibers – spread within ventricle walls
Ventricles contract

35. Homeostatic Imbalances
Angina pectoris:
Heart muscle deprived of O2
Crushing chest pain
Myocardial infarction (Heart Attack):
Prolonged angina
Heart cells may die

36. Homeostatic Imbalances
Ischemia: lack of adequate blood supply to heart
Fibrillation: uncoordinated shuddering of heart muscle, useless pump
Major cause of death from heart attacks

37. Heartbeat Regulation
Amount of blood pumped at any one time must adjust to the current needs of the body (more is needed during strenuous exercise)
S-A node is innervated by branches of the sympathetic and parasympathetic divisions
Medulla oblongata maintains a balance between the sympathetic and parasympathetic divisions of the nervous system
Impulses from cerebrum or hypothalamus may also influence heart rate
So do body temperature and the concentrations of certain ions
Norepinephrine - increases contractions
Acetylcholine - decreases contractions

39. Electrocardiogram (ECG/EKG)
Records the electrical activity of the heart
Electrocardiograph: graphic record of heart activity

40. How to read an ECG P wave: atria contact
QRS complex: ventricles contract
T wave: ventricles relax

42. Abnormal EKG Tachycardia - >100 beats/min
Bradycardia - <60 beats/min
Flutter - rapid; beats/min.
Fibrillation - rapid; uncoordinated
Heart becomes useless as a pump

47. Overview of EKG

48. Blood Vessels
Vascular System: blood circulates inside closed transport systems
Types of Blood Vessels:
Arteries (takes blood away from heart)
Arterioles
Capillary beds
Venules
Veins (return blood back to heart)

49. Arteries Capillaries Veins Blood away from heart Thicker walls
Withstand high pressure
Aorta - largest
Vasoconstriction
Contract
Diameter reduced
Vasodilation
Relax
Diameter increased
Walls 1-cell thick
Exchange gases between blood and tissue cells
Form connections between arterioles and venules
Blood back to heart
Thinner walls
Low pressure
Large lumen
Valves: prevent blood backflow
Skeletal muscles enhance venous return

50. Varicose Veins
People stand for long periods of time  inactivity or pressure on veins
Blood pools in feet and legs
Valves weaken  veins become twisted & dilated
Treatment: compression stockings, exercise, laser treatment, surgery

51. Homeostatic Imbalances
Atherosclerosis – artery walls thicken due to fatty deposits (plaques)
Treatments
By-pass
Angioplasty (stent)

52. Atherosclerosis

53. Angioplasty vs. Bypass Surgery

54. Bypass

56. Congestive Heart Failure
Progressive weakening of heart
Low heart efficiency  circulation inadequate to meet tissue needs
Caused by:
Coronary atherosclerosis
Persistent high blood pressure
Multiple heart attacks – scar tissue

57. New heart surgery technology Untold stories of the ER

58. Vital Signs
Pulse: expansion & recoil of an artery with each beat of left ventricle
Pressure points (eg. carotid artery, radial artery)
Normal resting: beats/min

59. Vital Signs
Blood pressure: pressure of blood on inner walls of blood vessels
Directly related to volume of blood
What happens to when blood is lost?
Stroke volume  ~ 70ml discharged
Blood volume = sum of blood cells + plasma
Hypertension – persistent elevated blood pressure (>140/90)

61. Measuring Blood Pressure
Systolic pressure: peak of ventricular contraction (top #)
Diastolic pressure: ventricles relaxed (bottom #)
Written: Systolic/Diastolic
Normal: (120 mm Hg)/(70 mm Hg) or 120/70

62. Using a Sphygmomanometer
Wrap cuff around upper arm
Place stethoscope on brachial artery
Inflate cuff to 180 mm Hg
Slowly release air  listen for whooshing sounds in brachial artery (Korotkoff sounds)
Systolic: when sound begin to appear
Diastolic: when sounds disappear