1. By Jenny R. Sheriff, EMT-P, I/C
Cardiovascular A&P
By Jenny R. Sheriff, EMT-P, I/C

2. Objectives At the end of this lesson, the student will be able to:
Label parts of the heart on a diagram
Understand what each section of the heart does
Trace a drop of blood through the heart
Know and locate major veins and arteries

3. Objectives Cont’d Understand how the heart is perfused
Relate preload and afterload to stroke volume
Know Starling’s law
Label components of the electrical system
Recite how electricity moves throughout the heart to result in contraction

4. Outside of the heart Pericardial Sac Visceral layer (epicardium)
Parietal layer
Pericardial fluid
The pericardial sac is made up of 2 layers of tissue: the visceral layer (or epicardium), which lies closest to the heart, and the parietal layer. Between the 2 layers is the pericardial fluid. This fluid provides lubrication between the 2 layers to reduce friction during muscle movement (or cardiac contraction). There is approximately mL of pericardial fluid between the epicardium and parietal layer.

5. The Heart Endocardium Myocardium
Lines the inside chambers of the heart
Myocardium
Heart muscle
Specialized cells
The endocardium is made up of epithelial and connective tissues and lines the inside chambers of the heart.
The myocardium is the actual heart muscle and is made up of specialized cells. Myocardial cells have the special property of automaticity. This means the heart does not have to rely solely on the brain to function. It can, in fact, create electrical impulses independently.

6. The Heart Atria Ventricles Septum
Small chambers at the top of the heart
Pumps blood to the ventricls
Ventricles
Large chambers at the bottom of the heart
Pumps blood to the lungs and body
Septum
The heart is made up of 4 chambers: the left and right atria and the left and right ventricles. The atria are the small chambers at the top of the heart (the top of the heart is referred to as the base because this is the flattest part of the heart. The bottom is the apex because of the “point” of the left ventricle).
The ventricles are at the bottom of the heart and are larger than the atria. This is because they work against gravity and a pressure gradient created by blood already in the vessels.
The septum separates the left and right side of the heart. It is thickest between the ventricles, tapering off to a fibrous membrane between the atria.

7. You can see how the septum is thicker between the ventricles
You can see how the septum is thicker between the ventricles. This picture also shows how blood moves through the heart, which is also demonstrated in the video that follows this slide.

8. To view the video, right click on the slide and select “preview”
To view the video, right click on the slide and select “preview”. Be sure to have your sound on for the narrative.

9. The Heart Valves Cusps Papillary muscles Chordae tendineae 4 valves
3 tricuspid, 1 bicuspid
Cusps
“Leaves” of the valves
Papillary muscles
Chordae tendineae

11. Blood Vessels Arteries Veins Capillaries 3 layers of tissue arterioles
venules
Capillaries
3 layers of tissue
Tunica intima
Tunica media
Tunica adventitia

12. Major Arteries Aorta Ascending Descending 3 branches Brachiocephalic
Left common carotid
Left subclavian
Descending
2 branches

15. Major Arteries Pulmonary Carotids Radial Brachial Femoral
Only artery that carries deoxygenated blood
Carotids
Radial
Brachial
Femoral
Dorsalis Pedal

16. Major Veins Vena Cavae External Jugular Cephalic Median cubital
Superior and Inferior
External Jugular
Cephalic
Median cubital
Basilic
Pulmonary
Carries oxygenated blood

17. Capillaries
Nutrient and waste exchange

18. Vasculature of the heart
Coronary Arteries
RCA
LCA
Coronary Sinus

19. Coronary Arteries Branch off directly from aorta RCA LCA 9 branches
All 9 may or may not be present
LCA
2 branches
Lt. anterior descending artery (LAD)
Circumflex artery

20. Coronary Arteries RCA LCA
Blood supply for RA and RV, inferior LV, SA & AV nodes
LCA
Supplies blood to most of LV, interventricular septum, and sometimes the AV node

21. Cardiac Cycle Preload Afterload Stroke Volume Cardiac output
Ejection Fraction
Starlings law

22. Electrophysiology Cardiac pacemaker SA Node Internodal Pathways
AV node
Bundle of His
Purkinje Fibers

23. SA Node Main cardiac pacemaker 3 internodal pathways Bachman Bundle
Anterior
Middle
posterior
Bachman Bundle
Innervates LA
Located in RA near superior vena cava

24. AV Node In RA near coronary sinus
“Holds” conduction to allow for contraction

25. Bundle of His Located in the walls of the RA
Provides communication between atria and ventricles
Forms bundle branches

26. Left Bundle Branch Innervates LV and lt. side of septum
LAF (left anterior superior fascicle)
Travels through LV and purkinje fibers to innervate anterior and superior aspect of LV
LPF (left posterior fascicle)
Goes to purkinje fibers and innervates posterior and inferior aspects of LV
Fanlike structure

27. Purkinje Fibers Directly innervates the cardiac cells
Initiates ventricular depolarization
Made up of individual cells in the endocardium

28. Questions??