1. Cardiovascular System Module 5

2. Cardiovascular System at a Glance Functions of Cardiovascular (CV) System –Distribute blood to all areas of body –Delivery of needed substances to cells –Removal of wastes Organs of Cardiovascular System –Heart –Arteries –Capillaries –Veins

4. Anatomy and Physiology Also called circulatory system Maintains distribution of blood throughout body –Delivers oxygen and nutrients like glucose and amino acids to cells –Picks up carbon dioxide and other waste products from cells and delivers to lungs, liver, and kidneys for elimination

5. Anatomy and Physiology Is composed of: –Heart –Blood vessels Arteries Capillaries Veins Divided into pulmonary circulation and systemic circulation

6. Systemic Circulation Between heart and cells of body Carries oxygenated blood away from left side of heart to body Carries deoxygenated blood from body to right side of heart

7. Pulmonary Circulation Between heart and lungs Carries deoxygenated blood away from right side of heart to lungs Carries oxygenated blood from lungs to left side of heart

8. A schematic of the circulatory system illustrating the pulmonary circulation picking up oxygen from the lungs and the systemic circulation delivering oxygen to the body.

9. Heart Muscular pump –Made up of cardiac muscle fibers –Could be called a muscle instead of an organ Beats an average of 60 – 100 beats per minute (bpm), or about 100,000 times a day Each time the muscle contracts: –Blood is ejected from heart –Pushed throughout body within blood vessels

10. Heart Located in the mediastinum –More to left side of chest –Directly behind sternum About size of a fist Shaped like upside-down pear Tip of heart at lower edge –Called the apex

11. Location of the heart within the mediastinum of the thoracic cavity.

12. Heart Layers EndocardiumMyocardiumEpicardium Inner layer Lines heart chambers Smooth, thin layer that reduces friction as the blood passes through heart chambers Middle layer Thick muscle Contraction of this layer develops the pressure required to pump blood through blood vessels Outer layer Forms the visceral layer of pericardial sac Fluid between layers of pericardial sac reduces friction as heart beats

13. Internal view of the heart illustrating the heart chambers, heart layers, and major blood vessels associated with the heart.

14. Heart Chambers Divided into four chambers –Two atria –Two ventricles Heart is divided into right and left sides by a wall called the septum

15. Atria Left and right upper chambers Receiving chambers Blood returns to atria in veins –Superior and inferior vena cava –Pulmonary veins

16. Ventricles Left and right lower chambers Pumping chambers –Thick myocardium Blood exits ventricles into arteries –Aorta –Pulmonary artery

17. – Internal view of heart specimen illustrating heart chambers, septum, and heart valves.

18. Heart Valves Four valves in heart –Tricuspid, pulmonary, mitral, aortic Act as restraining gates to control direction of blood flow Found at entrance and exit to ventricles Allow blood to flow only in forward direction by blocking it from returning to previous chamber

19. Tricuspid Valve An atrioventricular valve Between right atrium and ventricle –Prevents blood in ventricle from flowing back into atrium Has 3 leaflets or cusps

20. Pulmonary Valve A semilunar valve Between right ventricle and pulmonary artery –Prevents blood in artery from flowing back into ventricle Semilunar – valve looks like half moon

21. Mitral Valve An atrioventricular valve Between left atrium and ventricle –Prevents blood in ventricle from flowing back into atrium Also called bicuspid valve - has two cusps

22. Aortic Valve A semilunar valve Between left ventricle and aorta –Prevents blood in aorta from flowing back into ventricle

23. Superior view of heart valves illustrating position, size, and shape of each valve.

24. Path of Blood Flow Through Heart 1.Deoxygenated blood from body enters relaxed right atrium via two large veins called: –Superior vena cava –Inferior vena cava 2.Right atrium contracts –Blood flows through tricuspid valve into relaxed right ventricle

25. Path of Blood Flow Through Heart 3. Right ventricle contracts –Blood is pumped through pulmonary valve into pulmonary artery –Carries blood to lungs 4.Relaxed left atrium receives blood that has been oxygenated by lungs –Blood enters left atrium from the four pulmonary veins

26. Path of Blood Flow Through Heart 5. Left atrium contracts –Blood flows through mitral valve into relaxed left ventricle 6.Left ventricle contracts –Blood is pumped through the aortic valve and into aorta –Largest artery in the body –Carries blood to all parts of body

27. The path of blood flow through the chambers of the left and right side of the heart.

28. Systole and Diastole Heart chambers alternate between: –Relaxing to fill –Contracting to push blood forward Relaxation phase is diastole Contraction phase is systole

29. Conduction System of the Heart Autonomic nervous system controls heart rate –Therefore, no voluntary control over heart Special heart tissue conducts electrical impulses –Stimulate different chambers to contract in correct order

30. Path of the Conduction System 1.Sinoatrial (SA) node, or pacemaker, is where electrical impulse begins –From SA node a wave of electricity travels through atria –Causing them to contract, or go into systole 2.Next, atrioventricular node (AV) is stimulated 3.This node transfers stimulation wave to bundle of His

31. Path of the Conduction System 4.Electrical wave travels down bundle branches within interventricular septum 5.Finally, Purkinje fibers in ventricular myocardium are stimulated –Results in ventricular systole

32. The conduction system of the heart.

33. An electrocardiogram (EKG) wave.

34. Blood Vessels Pipes that circulate blood through body Three types: –Arteries –Capillaries –Veins Lumen is the channel within blood vessels

35. Arteries Large thick-walled vessels Wall contains smooth muscle and can dilate or constrict As arteries travel through body they branch into progressively smaller vessels called arterioles

36. Arteries Carry blood away from heart –Towards either lungs or cells and tissues of body –Pulmonary artery carries deoxygenated blood to lungs –Aorta carries oxygenated blood to body Coronary arteries supply myocardium

37. Capillaries Network of tiny, thin-walled blood vessels called a capillary bed Connecting unit between arteries and veins –Arterial blood flows into capillary bed –Venous blood flows out of capillary bed Location for: –Oxygen and nutrients to diffuse out –Carbon dioxide and wastes to diffuse in

38. Veins Much thinner walls than arteries Much lower pressure system than in arteries –Have valves to insure blood flows only towards heart –Squeezing by skeletal muscles also assists blood return to heart Smallest veins are called venules

39. Veins Carry blood towards the heart –From either the lungs or the cells and tissues of body –Pulmonary veins carry oxygenated blood from lungs –Superior and inferior vena cava carry deoxygenated blood from body

40. Comparative structure of arteries, capillaries, and veins.

41. Blood Pressure Measurement of force exerted by blood against walls of a vessel May be affected by several characteristics of blood and blood vessels –Elasticity of arteries –Diameter of blood vessels –Viscosity of blood –Volume of blood –Amount of resistance to blood flow

42. Blood Pressure During ventricular systole –Blood is under great pressure –Gives highest pressure—systolic –Top number of blood pressure reading During ventricular diastole –Blood isn’t being pushed from heart at all –Blood pressure drops to lowest point— diastolic –Bottom number of blood pressure reading

46. BILL NYE THE SCIENCE GUY video clips on next 3 slides

50. There are 33 Root Words, 30 prefixes and 17 suffixes introduced in this chapter. You can produce 100s of terms from the parts! Focus on the definitions of the parts and you will be able to define terms by breaking them apart. CAUTION

51. READ YOUR TEXT- Beginning on pg 151 there are lists of word parts and terms for the cardiovascular system. Working on the end of the chapter review exercises is a great way to ensure you have a grasp on the content. REMEMBER

52. There are so many medical terms to learn focus on the definitions of the parts. This is the best way to build your new vocabulary. PERSPECTIVE

53. NEXT UP: BLOOD AND THE LYMPHATIC AND IMMUNE SYSTEMS Close this Window or Tab to return to Blackboard. How it all flows to keep us healthy