1. Cardiovascular System

2. Pulmonary Circulation
Systemic Circulation
Delivers blood to all body cells and carries away waste
Pulmonary Circulation
Eliminates carbon dioxide and oxygenates blood (lung pathwy)

3. Arteries and Veins Arteries Veins Carry blood AWAY from the heart
Carry blood TO the heart

4. Structure of the Heart
Heart Size: about 14 cm x 9 cm (the size of a fist)

5. Structure of the Heart Coverings:
Pericardium: encloses the heart like a bag
Pericardial cavity: contains fluid for the heart to float in reducing friction

6. Structure of the Heart Wall of the Heart:
Epicardium: outer layer, reduces friction
Myocardium: middle layer, mostly cardiac muscle
Endocardium: inner layer, blood vessels

7. Structure of the Heart

8. Pathway of blood through the heart
Label the major chambers, valves and blood vessels and draw the pathway of blood through the heart…

10. Heart Chambers and Valves
Atria: top chambers
Ventricles: bottom chambers
Septum: divides left and right sides
Atrioventricular Valve (AV) valves located between the atrium and the ventricle
Tricuspid: right side AV
Bicuspid: left side AV (Mitral valve)

11. Heart Chambers and Valves
Superior vena cava: vessel that returns blood from the heart from the upper body
Inferior vena cava: vessel that returns blood to the heart from the lower body

12. Heart Chambers and Valves
Coronary sinus: a collection of veins joined together to form a large vessel that collects blood from the heart muscle (myocardium). It delivers deoxygenated blood to the right atrium

13. Heart Chambers and Valves
Chordae tendinae/papillary muscles: muscles and tendons that hold the heart valves in place

14. Heart Chambers and Valves
Pulmonary Trunk/Arteries: large vessel that splits into the left and right pulmonary arteries (the only arteries that carry deoxygenated blood)
Pulmonary Valve: controls flow of blood into the pulmonary trunk
Pulmonary Veins: returns oxygenated blood from the lungs
Aorta: large vessel that delivers blood to the body
Aortic Valve: controls the flow of blood into the aorta

16. Branches of the aorta Ascending and Descending Aorta Aortic arch
Right and Left Coronary Arteries: supply blood to the heart itself
Brachiocephalic Artery: branches into the right subclavian and right common carotid
Right subclavian: supplies blood to the right arm
Left subclavian: supplies blood to the left arm
Common carotid: branches into left and right carotid, which supply blood to the head

17. Note that blood vessels are not symmetrical**

18. Blood vessels: arteries, veins, capillaries
Arteries: strong elastic vessels which carry blood moving away from the heart
Smallest ones are arterioles which connect to capillaries
Veins: Thinner, less muscular vessels carrying blood toward the heart
Smallest ones are called venules which connect to capillaries
Contain valves
Capillaries: penetrate nearly all tissues
Walls composed of a single layer of squamous cells
Allows exchange of materials between blood and tissues

19. Arteries, veins and capillaries

20. Control of Blood Flow
Precapillary sphincters: circular, valve-like muscle at arteriole-capillary junction

21. Control of Blood Flow
Vasoconstriction: narrowing blood vessel’s lumen (passageway)
Vasodilation: expanding blood vessel’s lumen

23. Control of Blood Flow
Blood flow through the veins is not very efficient
Important factors:
Sympathetic Nervous Pump
Skeletal Muscle Pump
Respiratory pump

24. Don’t be Nervous!
Sympathetic Nervous Pump: Sympathetic input causes vasoconstriction, which increases pressure, which drives blood back to the heart. When the body needs to mobilize more blood for physical activity, the sympathetic nervous system induces vasoconstriction of veins.

25. Move your muscles!
Skeletal Muscle Pump: Veins pass between skeletal muscles. The contraction of skeletal muscle squeezes the vein, thus increasing blood pressure in that section of the vein. Pressure causes the upstream valve (furthest from the heart) to close and the downstream valve (the one closest to the heart) to open. Repeated cycles of contraction and relaxation, as occurs in the leg muscles while walking, effectively pumps blood back to the heart.

26. Veins Pass Between Skeletal Muscles

27. Breathe In!
Respiratory pump: the act of breathing helps to drive venous blood out of the abdominal cavity. As air is inspired, the diaphragm descends and abdominal pressure increases. The increasing pressure squeezes veins and moves blood back toward the heart. The rhythmic movement of venous blood causes by the act of breathing is called the respiratory pump.

28. Atherosclerosis
Atherosclerosis is the major cause of coronary artery disease and stroke.
Blood flow is diminished and could become blocked
Due to development of fatty plaque

29. Risk Factors for Atherosclerosis
genetic predisposition
obesity
age
smoking
hypertension
diabetes
high cholesterol

30. Disorders of the Circulatory System
MVP: mitral valve prolapse
The mitral valve does not close all the way
Creates a clicking sound at the end of a contraction
Heart Murmurs: valves do not close completely
Causes an (often) harmless murmur sound
Sometimes holes can occur in the septum of the heart which can also cause a murmur
Normal:
Murmurs:

31. Disorders of the Circulatory System
Myocardial Infarction (MI): a blood clot obstructs a coronary artery
Commonly called a heart attack
Atherosclerosis: deposits of fatty materials form a “plaque” in arteries which reduces blood flow
Treatment: angioplasty, where a catheter is inserted into the artery and a balloon is used to stretch the walls
Stent and Angioplasty:
Heart Bypass:

32. Disorders of the Circulatory System
Hypertension: high blood pressure
The force within the arteries is too high
A sphygmomanometer can diagnose hypertension

33. Blood Pressure
Systolic occurs when blood is forced out of the left ventricle, and the aortic valve OPENS
This is the high number
Diastolic occurs when the aortic valve closes and the ventricle relaxes
This is the lower number
Average blood pressure: 120/80
Average heart rate 72

34. Blood Pressure
The cusps (flaps) of the bicuspid and tricuspid valves are anchored to the ventricle wall by chordae tendinae
This prevents valves from being pushed up into the atria during ventricular systole
SPHYGMOMANOMETER: device used to measure blood pressure

35. Blood Pressure Factors affecting blood pressure: Cardiac output
Blood volume (5Liters for avg adult)
Blood Viscosity
Peripheral Resistance