1. The Cardiovascular System
The cardiovascular system is composed of
Blood
Blood vessels
The blood vessels transport blood throughout the body
Heart
The heart is a muscular pump that pumps blood

2. The Blood Vessels Conduct Blood in Continuous Loops
Blood passes through the following loop of vessels moving away from the heart
Arteries
Arterioles
Capillaries
Venules
Veins
Blood returns to the heart from the veins

3. The Blood Vessels Conduct Blood in Continuous Loops
Arteries- carry blood away from the heart
Contain the thickest wall of the blood vessels
Blood is usually oxygenated
Arterioles-small arteries; carry blood to capillaries

4. The Blood Vessels Conduct Blood in Continuous Loops
Venule- small veins that carry blood away from the capillary
Vein- thinner walls than arteries; contain valves for one-way flow of blood.
Carry blood to the heart
Blood is usually deoxygentated

5. Valves & muscles moves blood in veins
Valve closed
Valve open
Muscle contraction squeezes the vein, pushing blood through the open valve toward the heart.
Skeletal muscles relax, and blood fills the valves and closes them.
Valve closed
(b)
Relaxed calf muscles
Contracted calf muscles
Figure 12.6b

6. The Blood Vessels Conduct Blood in Continuous Loops
Capillary- thinnest walls of all blood vessels
Capillary-has walls that are one cell thick
Site of exchange between the body and the blood

8. The Blood Vessels Conduct Blood in Continuous Loops
Most materials simply diffuse across the capillary wall into the cells by the force of both blood pressure and osmotic pressure
Figure 12.3

9. Blood Vessels Capillary-has the greatest total cross-sectional area
More capillaries in the body than arteries or veins
Figure 12.5

10. The Heart is a Muscular Pump
The heart is located in the Thorax (chest )
Pericardium- sac around the heart
Pericardial cavity is filled with fluid that cushions the heart

13. The Heart is a Muscular Pump
Heart wall has 3 layers:
Epicardium- outer layer
Myocardium- thick middle layer made of cardiac muscle
Endocardium- innermost layer
Figure 12.7a

14. The Heart is a Muscular Pump
The heart has 2 sides
Right side pumps blood to the lungs
Left side pumps blood to the body

15. The Heart is a double Pump
The right side of the heart
Contains blood low in oxygen (deoxygenated)
Pumps blood to the lungs
The left side of the heart
Contains blood rich in oxygen
Pumps blood out to the body

18. The Heart is a Muscular Pump
Heart has 4 chambers:
Atria- upper chambers; Left & right atrium
Ventricles- lower chambers; Left & right ventricles

19. The Heart Valves 4 heart valves 2 Atrioventricular ( AV ) Valves
2 semilunar valves
Closing of heart valves produce lub-dup heart sound

20. The Heart Valves AV valves - Separate the atria from ventricles
Both AV valves contain strings called chordae tendinae that keep the valve from turning inside out.
Tricuspid valve- separate right atrium from the right ventricle (3 flaps)
Bicuspid valve- separate left atrium from the left ventricle (2 flaps)

21. The Heart Valves Keep blood from flowing backwards
Semilunar valves - Separate the ventricles from the attached blood vessels
Keep blood from flowing backwards
Pulmonary semilunar valve- lead into the pulmonary artery
Aortic Semilunar valve- lead into the aorta

22. Pulmonary circulation vs Systemic circulation
Pulmonary Circuit- blood flow from the right side of the heart to the lungs and back to the left side of the heart

23. Pulmonary circulation vs Systemic circulation
Systemic Circuit- blood flow from the left side of the heart to the body and back to the right side of the heart

24. Pulmonary circulation vs Systemic circulation

25. The Heart is a Muscular Pump
The heart muscle is nourished by coronary circulation
Coronary arteries –supply the heart with oxygenated blood
Coronary veins- drain the heart

26. CARDIAC CYCLE = .85 SEC. Systole= contract Diastole= relax Time ATRIA
VENTRICLES
0.15 sec
SYSTOLE
DIASTOLE
0.30 sec
0.40 sec
Systole= contract
Diastole= relax

27. The cardiac cycle
Figure 12.11

28. Contraction of the heart
Sinoatrial Node- commonly called the pacemaker
Located in the wall of the upper right atrium
It generates it’s own Impulses due to it’s natural ability to leak sodium ions

29. Contraction of the heart
When the Sa node fires an electrical stimulus is sent across both upper chambers causing them to contract
Av node (located in the interatrial septum) picks up the stimulus and passes it to the AV bundle and purkinje fibers in the wall of the ventricles
Then the ventricles contract

30. Contraction Of The Heart

31. Regulation of Heart Beat
A combination of nervous and endocrine signals control the strength and rate of contraction of the heart

32. Electrocardiogram (ECG/EKG)
a recording of the electrical signals (voltage changes) across the myocardium
Abnormal patterns can indicate heart problems

33. Electrocardiogram (ECG/EKG)
A typical ECG/EKG consists of three waves
P wave
QRS wave
T wave

34. Electrocardiogram (ECG/EKG)
P wave- atrial depolarization & contraction
QRS wave- ventricular depolarization & contraction
T wave- recovery of the ventricles

36. Blood Pressure
Sphygmomanometer – an instrument used to measure blood pressure
Can provide early identification of hypertension, or high blood pressure, the silent killer

37. Blood Pressure Blood pressure
Highest (systolic) when the ventricles contract, sending blood into the arteries
Lowest (diastolic) when the heart relaxes between beats

38. Blood Pressure 120/80mmHg is normal blood pressure
120- pressure in the blood vessel when the ventricles contract
80- pressure in the blood vessel when the ventricles relax
Figure (2 of 2)

39. Cardiovascular Disease
Atheroscloerosis
A narrowing of the arteries due to fatty deposits and thickening of the wall
Can lead to heart attack or stroke
When this occurs in the arteries of the heart muscle, it is called coronary artery disease

40. Cardiovascular Disease (Angioplasty)
Angioplasty- blocked artery is opened by inserting a balloon.

41. Cardiovascular Disease (Coronary bypass)
Blood is rerouted around closed vessel by using a vein from the leg
Figure 12.18

42. Cardiovascular Disease
Figure 12.19

43. Cardiovascular Disease
Myocardial Infarction (heart attack) - part of the myocardium dies due to the lack of oxygen.
Heart failure
Condition in which the heart becomes an inefficient pump
Leads to shortness of breath, fatigue, and fluid accumulation

44. Lymphatic System Components of the lymphatic system Lymph
Fluid identical to interstitial fluid
Lymphatic vessels
Vessels through which lymph flows
Have one-way valves to prevent backflow
Lymphoid tissues and organs

45. Lymphatic System Functions of the lymphatic system
Return excess interstitial fluid to the bloodstream
Transport products of fat digestion from the small intestine to the bloodstream
Defend the body against disease-causing organisms and abnormal cells

46. Lymphatic System Elephantiasis
A condition in which parasites block lymphatic vessels, preventing the return of fluid to blood
Results in massive swelling, darkening, and thickening of the skin in the affected area

48. Lymphatic System Lymphatic capillaries
Extra fluid enters these microscopic tubules
Differ from blood capillaries
End blindly
More permeable
Drain into larger lymphatic vessels
Lymph eventually enters ducts that join with large veins at the base of the neck

50. Lymphatic System Lymph nodes Bean-shaped structures
Filter lymph as it flows through them
Contain macrophages and lymphocytes that actively defend against disease-causing organisms

51. Lymphatic System Lymphoid organs include Tonsils Thymus gland Spleen
Peyer’s patches (nodules along the small intestine)
Red bone marrow