1. CARDIOVASCULAR SYSTEM

2. INTRODUCTION: AKA: the circulatory system
Consists of the heart and a closed system of vessels called arteries, veins, and capillaries

3. Two Pathways Pulmonary Circulation Systemic Circulation
Carries blood to lungs and back
Systemic Circulation
Carries blood to body and back

4. Arteries: carries blood Away from heart
Large
Thick-walled, Muscular
Elastic
Oxygenated blood
Exception Pulmonary Artery
Carried under great pressure
Steady pulsating

5. Capillaries Smallest vessel Microscopic Walls one cell thick
Nutrients and gases diffuse here

6. Veins: Carries blood to heart
Carries blood that contains waste and CO2
Exception pulmonary vein
Blood not under much pressure
Valves to prevent much gravity pull

7. Varicose Veins Damaged Valves in Veins

8. Artery vs. Vein

9. SIZE,SHAPE & LOCATION OF HEART
4 chambered muscular organ
Shaped/sized roughly like a person’s closed fist
Lies in the mediastinum
2/3 of heart located on left side of the midline and 1/3 on the right.

10. Structure of the Heart Covering
PERICARDIUM is a loose-fitting sac and consist of two parts:
Fibrous portion tough, loose, and inelastic sac around the heart
Serous portion consist of two layers

11. Serous portion -layers
PARIETAL LAYER: lining inside of the fibrous pericardium
VISCERAL LAYER: is also known as the EPICARDIUM -It attaches to the large blood vessels at the top of the heart
PERICARDIAL SPACE is a space between the visceral layer (epicardium) and the parietal layer
Lubricating fluid secreted by the serous membrane known as PERICARDIAL FLUID

12. Wall of the Heart Three layers of tissue make up the heart wall:
Epicardium
Myocardium
Endocardium

13. Epicardium Outer layer Meaning “on the heart”
Is actually the visceral layer of the pericardium

14. Myocardium Makes up the bulk of the heart wall
Is the thick, contractile middle layer of cardiac muscle cells
Cardiac muscles do not fatigue

15. Endocardium The lining of the interior of the myocardial wall
Composed of a layer of endothelial tissue, which line the heart and blood vessels

16. Chambers of the Heart Interior is divided into 4 chambers (cavities)
ATRIA (ATRIUM) Two upper chambers
VENTRICLES Two lower chambers
SEPTUM the left chambers is separated form the right chambers by this heart wall

17. Atria Often called the “receiving chambers”
They receive blood from vessels termed veins
Myocardium is not as thick here

18. Ventricles The lower chambers
Receive blood from the atria and pump blood out of the heart into arteries
“primary pumping chambers”
Myocardium is thicker here

19. Valves of the heart
Are mechanical devices that permit the flow of blood in one direction only
Two Atrioventricular valves (AV)
Guard the opening between the atria and the ventricles
Two Semilunar valves (SL)
Located where the pulmonary artery (right ventricle) and the aorta (left ventricle) arise

20. Atrioventricular Valves
Tricuspid valve: consists of three flaps (cusps).
The free edge of each flap is anchored to the papillary muscles by several cordlike structures termed chordae tendineae
Bicuspid (or mitral valve): the left atrioventricular valve guards the left opening
Only has two flaps.
Both allow blood to flow from atria into ventricles but prevents it from flowing back.

21. Semilunar Valves Consist of half-moon shaped flaps
Pulmonary semilunar valve
Aortic semilunar valve

22. Blood Flow Through the Heart

23. Blood Pressure 2 types of pressure Systolic-
measures the pressure in the arteries when the heart beats (when the heart muscle contracts). The top number, which is also the higher of the two numbers.  
Diastolic-
measures the pressure in the arteries between heartbeats (when the heart muscle is resting between beats and refilling with blood). The bottom number, which is also the lower number.
A normal blood pressure is 120/80

24. Heart Rate
Or pulse, is the number of times your heart beats per minute.
Normal heart rate varies from person to person.
To get the most accurate reading, put your finger over your pulse and count the number of beats in 60 seconds.
The normal resting adult human heart rate ranges from 60–100 bpm.

25. Cardiac Output
Cardiac output is the volume of blood pumped by one ventricle in a given period of time. It is calculated by multiplying the stroke volume by the heart rate (HR).
CO= HR X SV
Stroke volume (SV) - the amount of blood pumped by one ventricle during a contraction
Calculated by subtracting the amount of blood after a contraction from the amount of blood in the ventricle before the contraction.
EDV − ESV = SV.
(End Diastolic Volume) - (End Systolic Volume)

26. Echocardiogram a graphic outline of the heart's movement.
During an echo test, ultrasound (high-frequency sound waves) from a hand-held wand placed on your chest provides pictures of the heart's valves and chambers and helps evaluate the overall function of the heart.

27. Heartbeat Regulation
The heart beats due to a small electrical current by the cardiac conduction system. It has 5 major components:
1. The sinoatrial node (SA node): Known as the heart's "pacemaker", causes the heart to beat.

28. Heartbeat Regulation
2. The atrioventricular node (AV node): the electrical "relay station" between the upper and lower heart chambers. 3. The bundle of His: muscle fibers that conduct the electrical impulses that regulate heartbeat. 4. Bundle branches: Connected to the bundle of His, these lead to the lower ventricles. 5. Purkinje fibers: conduct impulses through the heart.

29. Cardiac Conduction System

30. How it works!
Special cells, produce electricity in the body by rapidly changing their electrical charge.
When the heart is relaxed the cells have a negative charge. Outside of the cells are positive.
Cells depolarize as some of their negative atoms move through the cell membrane, and it's this depolarization that causes electricity in the heart.

31. How it works -continued
Once one cell depolarizes it sparks a chain reaction and electricity flows from cell to cell.
When cells return to normal it's called repolarization, and the process is repeated with every heartbeat.